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Wang Y, Chang Y, Gao M, Zang W, Liu X. Genetic analysis of albinism caused by compound heterozygous mutations of the OCA2 gene in a Chinese family. Hereditas 2024; 161:8. [PMID: 38317267 PMCID: PMC10845747 DOI: 10.1186/s41065-024-00312-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 01/25/2024] [Indexed: 02/07/2024] Open
Abstract
BACKGROUND Oculocutaneous albinism (OCA) is a group of rare genetic disorders characterized by a reduced or complete lack of melanin in the skin, hair, and eyes. Patients present with colorless retina, pale pink iris, and pupil, and fear of light. The skin, eyebrows, hair, and other body hair are white or yellowish-white. These conditions are caused by mutations in specific genes necessary for the production of melanin. OCA is divided into eight clinical types (OCA1-8), each with different clinical phenotypes and potential genetic factors. This study aimed to identify the genetic causes of non-syndromic OCA in a Chinese Han family. METHODS We performed a comprehensive clinical examination of family members, screened for mutation loci using whole exome sequencing (WES) technology, and predicted mutations using In silico tools. RESULTS The patient's clinical manifestations were white skin, yellow hair, a few freckles on the cheeks and bridge of the nose, decreased vision, blue iris, poorly defined optic disk borders, pigmentation of the fundus being insufficient, and significant vascular exposure. The WES test results indicate that the patient has compound heterozygous mutations in the OCA2 gene (c.1258G > A (p.G420R), c.1441G > A (p.A481T), and c.2267-2 A > C), respectively, originating from her parents. Among them, c.1258G > A (p.G420R) is a de novo mutation with pathogenic. Our analysis suggests that compound heterozygous mutations in the OCA2 gene are the primary cause of the disease in this patient. CONCLUSIONS The widespread application of next-generation sequencing technologies such as WES in clinical practice can effectively replace conventional detection methods and assist in the diagnosis of clinical diseases more quickly and accurately. The newly discovered c.1258G > A (p.G420R) mutation can update and expand the gene mutation spectrum of OCA2-type albinism.
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Affiliation(s)
- Yanan Wang
- Genetics and Prenatal Diagnosis Department, Luoyang Maternal and Child Health Hospital, Luoyang, China.
| | - Yujie Chang
- Genetics and Prenatal Diagnosis Department, Luoyang Maternal and Child Health Hospital, Luoyang, China
| | - Mingya Gao
- Genetics and Prenatal Diagnosis Department, Luoyang Maternal and Child Health Hospital, Luoyang, China
| | - Weiwei Zang
- Genetics and Prenatal Diagnosis Department, Luoyang Maternal and Child Health Hospital, Luoyang, China
| | - Xiaofei Liu
- Genetics and Prenatal Diagnosis Department, Luoyang Maternal and Child Health Hospital, Luoyang, China
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2
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Chen C, Li J, Wang B, Wang Y, Yu X. TYR mutation in a Chinese population with oculocutaneous albinism: Molecular characteristics and ophthalmic manifestations. Exp Eye Res 2024; 239:109761. [PMID: 38145795 DOI: 10.1016/j.exer.2023.109761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 12/07/2023] [Accepted: 12/19/2023] [Indexed: 12/27/2023]
Abstract
Oculocutaneous albinism (OCA) is a rare inherited disorder characterized by a partial or complete reduction of melanin biosynthesis that leads to hypopigmentation in the skin, hair and eyes. The OCA1 subtype is caused by mutations in TYR. The purpose of this study was to investigate the genetic and clinical ophthalmic characteristics of TYR mutations in patients with OCA. Herein, 51 probands with a clinical diagnosis of OCA were enrolled. Whole-exome sequencing and comprehensive ophthalmic examinations were performed. Overall, TYR mutations were detected in 37.3% (19/51) in the patients with OCA. Fifteen patients had compound heterozygous variants, and four cases had homozygous variants. Eleven different pathogenic variants in TYR were detected in these 19 patients, with missense, insertion, delins and nonsense in 71.1% (27/38), 15.8% (6/38), 2.6% (1/38), and 10.5% (4/38), respectively. Clinical examinations revealed that 84.2% (16/19) of patients were OCA1A, and 15.8% (3/19) were OCA1B. Most TYR probands (52.6%, 10/19) had moderate vision impairment, 15.8% (3/19) had severe visual impairment, 10.5% (2/19) exhibited blindness, only 5.3% (1/19) had mild visual impairment and 15.8% (3/19) were not available. Photophobia and nystagmus were found in 100% (19/19) of the patients. In addition, grade 4 foveal hypoplasia was detected in 100% (12/12) of the patients. In conclusion: The TYR patients exhibited severe ocular phenotypes: the majority (93.8%, 15/16) of them had a moderate vision impairment or worse, and 100% (12/12) had severe grade 4 foveal hypoplasia. These novel findings could provide insight into the understanding of OCA.
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Affiliation(s)
- Chonglin Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Jun Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Bingqi Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Yinghuan Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Xinping Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China.
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3
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Jiang B, Zhang H, Kan Y, Gao X, Du Z, Liu Q. Novel compound heterozygous mutations in OCA2 gene were identified in a Chinese family with oculocutaneous albinism. Mol Genet Genomic Med 2024; 12:e2297. [PMID: 37882226 PMCID: PMC10767448 DOI: 10.1002/mgg3.2297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/18/2023] [Accepted: 09/27/2023] [Indexed: 10/27/2023] Open
Abstract
BACKGROUND Oculocutaneous albinism (OCA) is a group of rare autosomal recessive disorders characterized by clinical genetic heterogeneity. OCA type II (OMIM: 203200) is the most common subtype among African and African Americans, primarily caused by pathogenic variants in the OCA2 (HGNC ID: 8101) gene. In this study, we presented a Chinese family with OCA and reported two novel variants in the OCA2 gene. METHODS Whole-exome sequencing (WES) was performed to identify pathogenic variants in the proband. The candidate variants were subsequently validated using Sanger sequencing and QPCR assay. Additionally, bioinformatics analyses were employed to predict the deleteriousness and conservation of the identified mutations. RESULTS In the 16-year-old male proband, two novel compound heterozygous OCA2 variants, NM_000275.3: c.1640T>G (NP_000266.2: p.L547R) and an exons 10-19 deletion variant, were identified. Meanwhile, a reported heterozygous variant c.1441G>A/p.A481T (NM_000275.3, NP_000266.2) in the OCA2 gene was also found in the proband. Sanger sequencing confirmed that the two variants c.1441G>A/p.A481T and c.1640T>G/p.L547R were inherited from his father. Moreover, qPCR assay revealed that the exons 10-19 deletion was inherited from the mother, his sister also carried this variant. Fortunately, the variant was not detected in the amniotic fluid of the proband's sister. Multiple online bioinformatics tools predicted the variant c.1640T>G to be damaging, leading to the replacement of a highly conserved leucine with an arginine. The gross exon 10-19 deletion in the OCA2 gene resulted in a truncated, non-functional protein losing the 3-9 transmembrane α-helices domains. According to the American College of Medical Genetics and Genomics classification, these three variants in the OCA2 gene were evaluated as likely pathogenic. CONCLUSION This study has identified two novel compound variants in the OCA2 gene and a previously reported variant in a Chinese family with OCA. By expanding the mutation spectrum of the OCA2 gene, our findings contribute to a better understanding of the genetic basis of OCA.
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Affiliation(s)
- Beilei Jiang
- Prenatal Diagnosis CenterBinhu District of Hefei First People's HospitalHefeiAnhuiChina
| | - Hua Zhang
- Prenatal Diagnosis CenterBinhu District of Hefei First People's HospitalHefeiAnhuiChina
| | - Yuling Kan
- Central LaboratoryBinzhou People's HospitalBinzhouShandongChina
| | - Xueping Gao
- Yinfeng Gene Technology Co, LtdJinanShandongChina
| | - Zhaoli Du
- Yinfeng Gene Technology Co, LtdJinanShandongChina
| | - Quan Liu
- Prenatal Diagnosis CenterBinhu District of Hefei First People's HospitalHefeiAnhuiChina
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4
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Si S, Jia X, Xu L, Qin Q, Wu J, Ji W, Dong K, Zhang X, Cao L, Wang H, Liu P, Wang R, Bai J, Fu S, Huang Y, Sun W. Identification and characterization of the compound heterozygous variants of TYR gene in a northern Chinese family with Oculocutaneous albinism type 1. Pigment Cell Melanoma Res 2023; 36:472-480. [PMID: 37403904 DOI: 10.1111/pcmr.13111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 06/01/2023] [Accepted: 06/21/2023] [Indexed: 07/06/2023]
Abstract
Oculocutaneous albinism (OCA) is a genetically heterogeneous disease and is most inherited in an autosomal recessive manner. The characteristic manifestation of OCA is due to disfunction of melanin synthesis. OCA1 is the most severe subtype of OCA and is caused by homozygous or compound heterozygous variants in tyrosinase (TYR) gene, which is the key gene for melanin synthesis. This study aimed to identify the genetic variants of a northern Chinese family with OCA1. Clinical information and peripheral blood samples were collected. PCR amplification and Sanger sequencing were used to detect the entire exons and adjacent flanking sequences of TYR gene. Functional prediction of variants was performed by various bioinformatic analyses, while the pathogenicity classification of variants was evaluated according to ACMG standards and guidelines. A missense variant NM_000372.5:c.107G > C;NP_000363.1:p.C36S was discovered in TYR gene which converted cysteine to serine. Another variant in intron, NM_000372.5:c.1037-7 T > A, also affected the function of TYR gene. We verified the pathogenicity of the intron variant with a pCAS2 mini-gene based splicing assay and found that c.1037-7 T > A led to an insertion of 5 bp upstream from the common acceptor site of exon 3, which caused a frameshift TYR:c.1037-7 T > A:p.G346Efs*11. The results showed that the compound heterozygous variants c.107G > C:p.C36S and c.1037-7 T > A:p.G346Efs*11 of TYR gene were the pathogenic variants for this OCA1 family.
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Affiliation(s)
- Shuhan Si
- Laboratory of Medical Genetics (Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China, Ministry of Education), Harbin Medical University, Harbin, China
| | - Xueyuan Jia
- Laboratory of Medical Genetics (Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China, Ministry of Education), Harbin Medical University, Harbin, China
| | - Lidan Xu
- Laboratory of Medical Genetics (Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China, Ministry of Education), Harbin Medical University, Harbin, China
| | - Qian Qin
- Laboratory of Medical Genetics (Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China, Ministry of Education), Harbin Medical University, Harbin, China
| | - Jie Wu
- Laboratory of Medical Genetics (Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China, Ministry of Education), Harbin Medical University, Harbin, China
| | - Wei Ji
- Laboratory of Medical Genetics (Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China, Ministry of Education), Harbin Medical University, Harbin, China
| | - Kexian Dong
- Laboratory of Medical Genetics (Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China, Ministry of Education), Harbin Medical University, Harbin, China
| | - Xuelong Zhang
- Laboratory of Medical Genetics (Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China, Ministry of Education), Harbin Medical University, Harbin, China
| | - Lin Cao
- Department of Hepatopancreatobiliary Surgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Hao Wang
- Department of Hepatopancreatobiliary Surgery, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Peng Liu
- Laboratory of Medical Genetics (Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China, Ministry of Education), Harbin Medical University, Harbin, China
| | - Rongrong Wang
- McKusick-Zhang Center for Genetic Medicine, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China
| | - Jing Bai
- Laboratory of Medical Genetics (Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China, Ministry of Education), Harbin Medical University, Harbin, China
| | - Songbin Fu
- Laboratory of Medical Genetics (Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China, Ministry of Education), Harbin Medical University, Harbin, China
| | - Yun Huang
- Laboratory of Medical Genetics (Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China, Ministry of Education), Harbin Medical University, Harbin, China
| | - Wenjing Sun
- Laboratory of Medical Genetics (Key Laboratory of Preservation of Human Genetic Resources and Disease Control in China, Ministry of Education), Harbin Medical University, Harbin, China
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Dolinska MB, Anderson DE, Sergeev YV. In vitro characterization of the intramelanosomal domain of human recombinant TYRP1 and its oculocutaneous albinism type 3-related mutant variants. Protein Sci 2023; 32:e4518. [PMID: 36412553 PMCID: PMC9793978 DOI: 10.1002/pro.4518] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 11/16/2022] [Accepted: 11/18/2022] [Indexed: 11/23/2022]
Abstract
Tyrosinase related protein 1 (TYRP1) is the most abundant melanosomal protein of the melanocyte, where plays an important role in the synthesis of eumelanin, possibly catalyzing the oxidation of 5,6-dihydroxyindole-2-carboxylic acid to 5,6-quinone-2-carboxylic acid. Mutations to the TYRP1 gene can result in oculocutaneous albinism type 3 (OCA3), a rare disease characterized by reduced synthesis of melanin in skin, hair, and eyes. To investigate the effect of genetic mutations on the TYRP1 structure, function, and stability, we engineered the intramelanosomal domain of TYRP1 and its mutant variants mimicking either OCA3-related changes, C30R, H215Y, D308N, and R326H or R87G mutant variant, analogous to OCA1-related pathogenic effect in tyrosinase. Proteins were produced in Trichoplusia Ni larvae, then purified, and analyzed by biochemical methods. Data shows that D308N and R326H mutants keep the native conformations and demonstrate no change in their stability and enzymatic activity. In contrast, mutations C30R and R87G localized in the Cys-rich domain show the variants misfolding during the purification process. The H215Y variant disrupts the binding of Zn2+ in the active site and thus reduces the strength of the enzyme/substrate interactions. Our results, consistent with the clinical and in silico studies, show that mutations at the protein surface are expected to have a negligible phenotype change compared to that of TYRP1. For the mutations with severe phenotype changes, which were localized in the Cys-rich domain or the active site, we confirmed a complete or partial protein misfolding as the possible mechanism of protein malfunction caused by OCA3 inherited mutations.
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Affiliation(s)
| | - David E. Anderson
- National Institute of Diabetes and Digestive and Kidney DiseasesNational Institutes of HealthBethesdaMarylandUSA
| | - Yuri V. Sergeev
- National Eye InstituteNational Institutes of HealthBethesdaMarylandUSA
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6
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Thuong MTH, Anh LTL, Nhung VP, Ngoc TTB, Lan HT, Phuong DK, Ha NH, Van Hai N, Ton ND. Genetic analyses of Vietnamese patients with oculocutaneous albinism. J Clin Lab Anal 2022; 36:e24625. [PMID: 35870188 PMCID: PMC9459276 DOI: 10.1002/jcla.24625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/12/2022] [Accepted: 07/13/2022] [Indexed: 11/07/2022] Open
Affiliation(s)
- Ma Thi Huyen Thuong
- Institute of Genome Research (IGR) Vietnam Academy of Science and Technology (VAST) Ha Noi Vietnam
- Graduated University of Science and Technology Vietnam Academy of Science and Technology (VAST) Ha Noi Vietnam
| | - Luong Thi Lan Anh
- Department of Medical Biology and Genetics Hanoi Medical University Hanoi Viet Nam
| | - Vu Phuong Nhung
- Institute of Genome Research (IGR) Vietnam Academy of Science and Technology (VAST) Ha Noi Vietnam
| | - Tran Thi Bich Ngoc
- Institute of Genome Research (IGR) Vietnam Academy of Science and Technology (VAST) Ha Noi Vietnam
| | - Hoang Thu Lan
- Department of Medical Biology and Genetics Hanoi Medical University Hanoi Viet Nam
| | - Doan Kim Phuong
- Department of Medical Biology and Genetics Hanoi Medical University Hanoi Viet Nam
| | - Nguyen Hai Ha
- Institute of Genome Research (IGR) Vietnam Academy of Science and Technology (VAST) Ha Noi Vietnam
- Graduated University of Science and Technology Vietnam Academy of Science and Technology (VAST) Ha Noi Vietnam
| | - Nong Van Hai
- Institute of Genome Research (IGR) Vietnam Academy of Science and Technology (VAST) Ha Noi Vietnam
- Graduated University of Science and Technology Vietnam Academy of Science and Technology (VAST) Ha Noi Vietnam
| | - Nguyen Dang Ton
- Institute of Genome Research (IGR) Vietnam Academy of Science and Technology (VAST) Ha Noi Vietnam
- Graduated University of Science and Technology Vietnam Academy of Science and Technology (VAST) Ha Noi Vietnam
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7
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Zhong Z, Zhou Z, Chen J, Zhang J. Identification of 12 OCA Cases in Chinese Population and Two Novel Variants. Front Genet 2022; 13:926511. [PMID: 35923705 PMCID: PMC9340472 DOI: 10.3389/fgene.2022.926511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/09/2022] [Indexed: 11/21/2022] Open
Abstract
OCA (oculocutaneous albinism) refers to a group of heterogeneous congenital disorders of which the common manifestations are variable degrees of cutaneous hypopigmentation and significant visual impairment, including poor visual acuity, photophobia, and nystagmus. Molecular analysis may elucidate its pathogenesis and be in favor of accurate diagnosis. High-throughput sequencing and Sanger sequencing were performed to detect mutational alleles and in silico analysis was performed for prediction of variant pathogenicity. Ten TYR-related and two OCA2-related patients were identified with 16 different variants with potential pathogenicity. Two novel missense variants [TYR: c.623T > G, p(Leu208Arg) and OCA2: c.1325A > G, p(Asn442Ser)] are identified in this study, and three OCA cases are reported for the first time in Chinese population based on their associated variants. Analysis of crystal structures of TYR ortholog and its paralog TYRP1 suggests that the substitution of Leu208 may have an impact on protein stability. This study may facilitate OCA diagnosis by expanding the mutational spectrum of TYR and OCA2 as well as further basic studies about these two genes.
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Affiliation(s)
- Zilin Zhong
- Birth Defect Group, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People’s Hospital, School of Medicine, Tongji University, Shanghai, China
- Department of Regenerative Medicine, School of Medicine, Tongji University, Shanghai, China
| | - Zheng Zhou
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jianjun Chen
- Birth Defect Group, Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People’s Hospital, School of Medicine, Tongji University, Shanghai, China
- Department of Medical Genetics, School of Medicine, Tongji University, Shanghai, China
- *Correspondence: Jianjun Chen, Jun Zhang,
| | - Jun Zhang
- Research Center for Translational Medicine, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Stem Cell Translational Research Center of Tongji Hospital, School of Medicine, Tongji University, Shanghai, China
- *Correspondence: Jianjun Chen, Jun Zhang,
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Xiao Y, Zhou C, Xie H, Huang S, Wang J, Liu S. NGS-based targeted sequencing identified two novel variants in Southwestern Chinese families with oculocutaneous albinism. BMC Genomics 2022; 23:332. [PMID: 35488210 PMCID: PMC9055679 DOI: 10.1186/s12864-022-08597-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 04/27/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Oculocutaneous albinism (OCA) is a group of heterogeneous genetic diseases characterized by a reduction or complete lack of pigmentation in the hair, skin, and eyes. It is associated with reduced visual acuity, nystagmus, photophobia, and strabismus. OCA type 1 (OCA1) and type 2 (OCA2) are caused by mutations in the tyrosinase (TYR) and OCA2 genes, which are responsible for most cases of OCA. The present study aimed to identify the mutational spectra of 18 southwest Chinese probands with OCA. RESULTS We used a skin disease-targeted panel to sequence more than 400 genes, including 23 genes (TYR, OCA2, AP3B1, BLOC1S3, BLOC1S6, C10orf11, DTNBP1, FRMD7, GPR143, HPS1, HPS3, HPS4, HPS5, HPS6, LYST, MC1R, MITF, MLPH, MYO5A, RAB27A, SLC24A5, SLC45A2, TYRP1) associated with syndromic and non-syndromic albinism. The targeted panel was applied to 18 patients from southwest China, nine (50%) patients were diagnosed with OCA1, and nine (50%) were diagnosed with OCA2. Our data indicate that OCA1 and OCA2, the most common subtypes, probably have the same prevalence in southwest China. In total, we identified 26 variants in TYR and OCA2 from 18 OCA cases using the NGS technology, including 24 variants presented in the Human Gene Mutation Database Professional (HGMD) and two novel variants, c.559_560insCATTATTATGTGTCAAATTATCCCC in TYR and c.1514 T > C in OCA2, which have not been previously reported. According to the American College of Medical Genetics and Genomics (ACMG) classification, c.559_560insCATTATTATGTGTCAAATTATCCCC (p.G190Cfs*12) is classified as a pathogenic variant, and c.1514 T > C (p.F505S) is evaluated as a likely pathogenic variant. CONCLUSIONS Two novel variants were identified which will expand the mutational spectra of TYR and OCA2. The results of the present study may have implications for genetic counseling, carrier screening, and clinical management of the disease.
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Affiliation(s)
- Yuanyuan Xiao
- Department of Obstetrics and Gynecology, West China Second University Hospital of Sichuan University, Chengdu, 610041, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, China
| | - Cong Zhou
- Department of Obstetrics and Gynecology, West China Second University Hospital of Sichuan University, Chengdu, 610041, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, China
| | - Hanbing Xie
- Department of Obstetrics and Gynecology, West China Second University Hospital of Sichuan University, Chengdu, 610041, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, China
| | - Shuang Huang
- Department of Obstetrics and Gynecology, West China Second University Hospital of Sichuan University, Chengdu, 610041, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, China
| | - Jing Wang
- Department of Obstetrics and Gynecology, West China Second University Hospital of Sichuan University, Chengdu, 610041, China. .,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, China.
| | - Shanling Liu
- Department of Obstetrics and Gynecology, West China Second University Hospital of Sichuan University, Chengdu, 610041, China. .,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, Sichuan University, Chengdu, 610041, China.
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9
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Li C, Chen Q, Wu J, Ren J, Zhang M, Wang H, Li J, Tang Y. Identification and characterization of two novel noncoding tyrosinase (TYR) gene variants leading to oculocutaneous albinism type 1. J Biol Chem 2022; 298:101922. [PMID: 35413289 PMCID: PMC9108984 DOI: 10.1016/j.jbc.2022.101922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 04/01/2022] [Accepted: 04/03/2022] [Indexed: 11/25/2022] Open
Abstract
Oculocutaneous albinism type 1 (OCA1), resulting from pathogenic variants in the tyrosinase (TYR) gene, refers to a group of phenotypically heterogeneous autosomal recessive disorders characterized by a partial or a complete absence of pigment in the skin/hair and is also associated with common developmental eye defects. In this study, we identified two novel compound heterozygous TYR variants from a Chinese hypopigmentary patient by whole-exome sequencing. Specifically, the two variants were c.-89T>G, located at the core of the initiator E-box (Inr E-box) of the TYR promoter, and p.S16Y (c.47C>A), located within the signal sequence. We performed both in silico analysis and experimental validation and verified these mutations as OCA1 variants that caused either impaired or complete loss of function of TYR. Mechanistically, the Inr E-box variant dampened TYR binding to microphthalmia-associated transcription factor, a master transcriptional regulator of the melanocyte development, whereas the S16Y variant contributed to endoplasmic reticulum retention, a common and principal cause of impaired TYR activity. Interestingly, we found that the Inr E-box variant creates novel protospacer adjacent motif sites, recognized by nucleases SpCas9 and SaCas9-KKH, respectively, without compromising the functional TYR coding sequence. We further used allele-specific genomic editing by CRISPR activation to specifically target the variant promoter and successfully activated its downstream gene expression, which could lead to potential therapeutic benefits. In conclusion, this study expands the spectrum of TYR variants, especially those within the promoter and noncoding regions, which can facilitate genetic counseling and clinical diagnosis of OCA1.
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Affiliation(s)
- Chaoyi Li
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China; Aging Research Center, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Qian Chen
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China; Aging Research Center, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Junjiao Wu
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China; Department of Rheumatology and Immunology, Xiangya Hospital, Central South University, Changsha, China; Provincial Clinical Research Center for Rheumatic and Immunologic Diseases, Xiangya Hospital, Central South University, Changsha, China
| | - Jie Ren
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China; Aging Research Center, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Mengfei Zhang
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China; Aging Research Center, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Huakun Wang
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China; Aging Research Center, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Jinchen Li
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China; Aging Research Center, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Yu Tang
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, China; Aging Research Center, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China; The Biobank of Xiangya Hospital, Central South University, Changsha, China.
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10
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Xiong HY, Shi YQ, Zhong C, Yang Q, Zhang G, Yang H, Wu D, Chen Y, Li Q, Wang M. Detection of De Novo PAX2 Variants and Phenotypes in Chinese Population: A Single-Center Study. Front Genet 2022; 13:799562. [PMID: 35444690 PMCID: PMC9014304 DOI: 10.3389/fgene.2022.799562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 03/01/2022] [Indexed: 11/13/2022] Open
Abstract
Background:PAX2 is a nuclear transcription factor gene that is highly conserved among species. Variants within PAX2 could result in optic nerve colobomas and kidney hypoplasia. However, little clinical and genetic information is currently available about PAX2 variants in Chinese children. Objective: This study aims to further understand the clinical manifestations and genetic characteristics of PAX2 variants in Chinese population. Methods: In this single-center retrospective study, we analyzed the clinical data of 10 children identified as carriers of PAX2 variants by gene sequencing. All the variants found in this study were analyzed using in silico prediction and American College of Medical Genetics and Genomics (ACMG) standards and guidelines. Results: The mean age for developing the first symptom in 10 unrelated children was 7.2 years old. Proteinuria and bilateral kidney dysplasia were found in every patient. Two children underwent kidney histological examination; one child showed high-intensity C1q deposition in the kidney, and the other child showed focal segmental glomerular sclerosis (FSGS). Three children had PAX2-related ocular abnormalities, including nystagmus, retinal exudation, amblyopia, microphthalmia, microcornea, and total blindness. In addition, one patient had the comorbidity of oculocutaneous albinism (OCA). Eight different PAX2 variants were found in ten patients, three of which were reported for the first time. Conclusion: We reported some patients with unique manifestations and comorbidities, and we reported three variants that have not been previously identified. The PAX2 gene is prone to spontaneous variants, and the outcome of patients is unfavorable. Because of the lack of specific therapy, genetic testing should be recommended for individuals with obvious evidence of kidney dysplasia and eye abnormalities, and kidney protective treatment should be initiated early.
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Affiliation(s)
- Hua-Ying Xiong
- Department of Nephrology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, National Clinical Research Center for Child Health and Disorders, Pediatric Research Institute, Chongqing, China
| | - Yong-Qi Shi
- Department of Nephrology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, National Clinical Research Center for Child Health and Disorders, Pediatric Research Institute, Chongqing, China
| | - Cheng Zhong
- Department of Nephrology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, National Clinical Research Center for Child Health and Disorders, Pediatric Research Institute, Chongqing, China
| | - Qin Yang
- Department of Nephrology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, National Clinical Research Center for Child Health and Disorders, Pediatric Research Institute, Chongqing, China
| | - Gaofu Zhang
- Department of Nephrology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, National Clinical Research Center for Child Health and Disorders, Pediatric Research Institute, Chongqing, China
| | - Haiping Yang
- Department of Nephrology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, National Clinical Research Center for Child Health and Disorders, Pediatric Research Institute, Chongqing, China
| | - Daoqi Wu
- Department of Nephrology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, National Clinical Research Center for Child Health and Disorders, Pediatric Research Institute, Chongqing, China
| | - Yaxi Chen
- Key Laboratory of Molecular Biology for Infectious Diseases, Department of Infectious Diseases, Ministry of Education, Centre for Lipid Research, The Second Affiliated Hospital, Institute for Viral Hepatitis, Chongqing Medical University, Chongqing, China
| | - Qiu Li
- Department of Nephrology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, National Clinical Research Center for Child Health and Disorders, Pediatric Research Institute, Chongqing, China
- *Correspondence: Qiu Li, ; Mo Wang,
| | - Mo Wang
- Department of Nephrology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, National Clinical Research Center for Child Health and Disorders, Pediatric Research Institute, Chongqing, China
- *Correspondence: Qiu Li, ; Mo Wang,
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11
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Wei A, Zhang T, Yuan Y, Qi Z, Bai D, Zhang Y, Zhang Y, Liu T, Huang Q, Yang X, Li W. Spectrum Analysis of Albinism Genes in a Large Cohort of Chinese Index Patients. J Invest Dermatol 2021; 142:1752-1755.e3. [PMID: 34838614 DOI: 10.1016/j.jid.2021.11.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/02/2021] [Accepted: 11/12/2021] [Indexed: 11/30/2022]
Affiliation(s)
- Aihua Wei
- Department of Dermatology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Tianjiao Zhang
- Department of Dermatology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yefeng Yuan
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing, China
| | - Zhan Qi
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing, China; MOE Key Laboratory of Major Diseases in Children, Beijing, China; Rare Disease Center, National Center for Children's Health, Beijing, China; Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Dayong Bai
- Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Yingzi Zhang
- Department of Dermatology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yunlan Zhang
- Department of Dermatology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Teng Liu
- Department of Dermatology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Qiaorong Huang
- Department of Dermatology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xiumin Yang
- Department of Dermatology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Wei Li
- Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute, Beijing, China; MOE Key Laboratory of Major Diseases in Children, Beijing, China; Rare Disease Center, National Center for Children's Health, Beijing, China; Beijing Children's Hospital, Capital Medical University, Beijing, China.
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12
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Ma L, Zhu J, Wang J, Huang Y, Zhang J, Wang C, Zhou Y, Peng D. Genetic Analysis of 28 Chinese Families With Tyrosinase-Positive Oculocutaneous Albinism. Front Genet 2021; 12:715437. [PMID: 34707637 PMCID: PMC8544823 DOI: 10.3389/fgene.2021.715437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 07/30/2021] [Indexed: 11/28/2022] Open
Abstract
Background Tyrosinase-positive oculocutaneous albinism (OCA, type II, OCA2) is an autosomal recessive genetic disease in which the biosynthesis of melanin decreases in the skin, hair, and eyes. OCA2 disease is caused by mutations in OCA2 gene. The gene product plays a role in regulating the pH of melanosomes. Up to now, hundreds of OCA2 mutations have been reported and novel variants are still being discovered. Methods In this study, we reviewed the records of OCA2 patients who had conducted albinism genetic testing, and then analyzed the clinical and genetic information of 28 OCA2 patients who had been genetically diagnosed by using Sanger sequencing and next-generation sequencing. Results In this study, we reported 31 variants screened from 28 Chinese OCA2 families, and characterized the detailed molecular and clinical presentations. There were 12 novel variants among all detected variants, including 3 missense variants (p.G393V, p.T482A, and p.R720P), 4 frameshift variants (p.R53Gfs∗49, p.N279Kfs∗17, p.I469Lfs∗4, p.I655Nfs∗12), 2 splicing variants (c.1637-2A > G, c.1951 + 1G > C), 2 stopgain variants (p.L278X, p.W652X) and 1 insertion variants (p.P315LinsT). One potential cluster of missense variants was implicated indicating the important roles of the underlying domains in OCA2 pathogenesis. Conclusion Our results were beneficial for diagnosis and precision clinical management for OCA2-related disorder, and this study expanded the mutation spectrum of oculocutaneous albinism.
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Affiliation(s)
- Linya Ma
- Department of Medical Genetics, Changde First People's Hospital, Changde, China
| | - Jianjian Zhu
- Department of Medical Genetics, Changde First People's Hospital, Changde, China
| | - Jing Wang
- Changsha Kingmed Center for Clinical Laboratory, Changsha, China
| | - Yazhou Huang
- Department of Medical Genetics, Changde First People's Hospital, Changde, China
| | - Jibo Zhang
- Department of Medical Genetics, Changde First People's Hospital, Changde, China
| | - Chao Wang
- Department of Medical Genetics, Changde First People's Hospital, Changde, China
| | - Yuan Zhou
- Department of Medical Genetics, Changde First People's Hospital, Changde, China
| | - Dan Peng
- Department of Medical Genetics, Changde First People's Hospital, Changde, China.,Affiliated Hospital of Changde City, University of South China, Hengyang, China
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13
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Loftus SK, Lundh L, Watkins-Chow DE, Baxter LL, Pairo-Castineira E, Nisc Comparative Sequencing Program, Jackson IJ, Oetting WS, Pavan WJ, Adams DR. A custom capture sequence approach for oculocutaneous albinism identifies structural variant alleles at the OCA2 locus. Hum Mutat 2021; 42:1239-1253. [PMID: 34246199 DOI: 10.1002/humu.24257] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 06/02/2021] [Accepted: 06/24/2021] [Indexed: 11/09/2022]
Abstract
Oculocutaneous albinism (OCA) is a heritable disorder of pigment production that manifests as hypopigmentation and altered eye development. Exon sequencing of known OCA genes is unsuccessful in producing a complete molecular diagnosis for a significant number of affected individuals. We sequenced the DNA of individuals with OCA using short-read custom capture sequencing that targeted coding, intronic, and noncoding regulatory regions of known OCA genes, and genome-wide association study-associated pigmentation loci. We identified an OCA2 complex structural variant (CxSV), defined by a 143 kb inverted segment reintroduced in intron 1, upstream of the native location. The corresponding CxSV junctions were observed in 11/390 probands screened. The 143 kb CxSV presents in one family as a copy number variant duplication for the 143 kb region. In the remaining 10/11 families, the 143 kb CxSV acquired an additional 184 kb deletion across the same region, restoring exons 3-19 of OCA2 to a copy-number neutral state. Allele-associated haplotype analysis found rare SNVs rs374519281 and rs139696407 are linked with the 143 kb CxSV in both OCA2 alleles. For individuals in which customary molecular evaluation does not reveal a biallelic OCA diagnosis, we recommend preliminary screening for these haplotype-associated rare variants, followed by junction-specific validation for the OCA2 143 kb CxSV.
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Affiliation(s)
- Stacie K Loftus
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Linnea Lundh
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Dawn E Watkins-Chow
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Laura L Baxter
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Erola Pairo-Castineira
- Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh, UK.,MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, UK
| | | | - Ian J Jackson
- Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh, UK.,MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, UK
| | - William S Oetting
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, Minnesota, USA
| | - William J Pavan
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - David R Adams
- Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
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14
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Evident hypopigmentation without other ocular deficits in Dutch patients with oculocutaneous albinism type 4. Sci Rep 2021; 11:11572. [PMID: 34078970 PMCID: PMC8172864 DOI: 10.1038/s41598-021-90896-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/05/2021] [Indexed: 02/04/2023] Open
Abstract
To describe the phenotype of Dutch patients with oculocutaneous albinism type 4 (OCA4), we collected data on pigmentation (skin, hair, and eyes), visual acuity (VA), nystagmus, foveal hypoplasia, chiasmal misrouting, and molecular analyses of nine Dutch OCA4 patients from the Bartiméus Diagnostic Center for complex visual disorders. All patients had severely reduced pigmentation of skin, hair, and eyes with iris transillumination over 360 degrees. Three unrelated OCA4 patients had normal VA, no nystagmus, no foveal hypoplasia, and no misrouting of the visual pathways. Six patients had poor visual acuity (0.6 to 1.0 logMAR), nystagmus, severe foveal hypoplasia and misrouting. We found two novel variants in the SLC45A2 gene, c.310C > T; (p.Pro104Ser), and c.1368 + 3_1368 + 9del; (p.?). OCA4 patients of this Dutch cohort all had hypopigmentation of skin, hair, and iris translucency. However, patients were either severely affected with regard to visual acuity, foveal hypoplasia, and misrouting, or visually not affected at all. We describe for the first time OCA4 patients with an evident lack of pigmentation, but normal visual acuity, normal foveal development and absence of misrouting. This implies that absence of melanin does not invariably lead to foveal hypoplasia and abnormal routing of the visual pathways.
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15
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Xu C, Xiang Y, Li H, Xu Y, Mao Y, Zhou L, Xu X, Tang S. Genetic analysis and prenatal diagnosis of 20 Chinese families with oculocutaneous albinism. J Clin Lab Anal 2020; 35:e23647. [PMID: 33124154 PMCID: PMC7891544 DOI: 10.1002/jcla.23647] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 10/09/2020] [Accepted: 10/11/2020] [Indexed: 12/27/2022] Open
Abstract
Background Oculocutaneous albinism (OCA) is a group of heterogeneous genetic disorders characterized by abnormal melanin synthesis in the hair, skin, and eyes. OCA exhibits obvious genetic and phenotypic heterogeneity. Molecular diagnosis of causal genes can be of help in the classification of OCA subtypes and the study of OCA pathogenesis. Methods In this study, Sanger sequencing and whole exome sequencing were used to genetically diagnose 20 nonconsanguineous Chinese OCA patients. In addition, prenatal diagnosis was provided to six OCA families. Results Variants of TYR, OCA2, and HPS1 were detected in 85%, 10%, and 5% of affected patients, respectively. A total of 21 distinct variants of these three genes were identified. Exons 1 and 2 were the hotspot regions of the TYR variants, and c.895C > A and c.896G > A were the hotspot variants. We also found seven novel variants: c.731G > A, c.741C > A, c.867C > A, and c.1037‐2A > T in TYR, c.695dupT and c.1054A > G in OCA2, and c.9C > A in HPS1. Genetic tests on six fetuses revealed three carrier fetuses, two normal fetuses, and one affected fetus. The follow‐up results after birth were consistent with the results of prenatal diagnosis (one fetus terminated during pregnancy was not followed up). Conclusions This study expands our understanding of the genotypic spectrum of the Chinese OCA population. The findings indicate that prenatal diagnosis can provide important information for genetic counseling.
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Affiliation(s)
- Chenyang Xu
- Key Laboratory of Birth Defects, Department of Genetics, Wenzhou Central Hospital, Wenzhou, China
| | - Yanbao Xiang
- Key Laboratory of Birth Defects, Department of Genetics, Wenzhou Central Hospital, Wenzhou, China
| | - Huanzheng Li
- Key Laboratory of Birth Defects, Department of Genetics, Wenzhou Central Hospital, Wenzhou, China
| | - Yunzhi Xu
- Key Laboratory of Birth Defects, Department of Genetics, Wenzhou Central Hospital, Wenzhou, China
| | - Yijian Mao
- Key Laboratory of Birth Defects, Department of Genetics, Wenzhou Central Hospital, Wenzhou, China
| | - Lili Zhou
- Key Laboratory of Birth Defects, Department of Genetics, Wenzhou Central Hospital, Wenzhou, China
| | - Xueqin Xu
- Key Laboratory of Birth Defects, Department of Genetics, Wenzhou Central Hospital, Wenzhou, China
| | - Shaohua Tang
- Key Laboratory of Birth Defects, Department of Genetics, Wenzhou Central Hospital, Wenzhou, China.,Key Laboratory of Medical Genetic, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, China
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16
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Le L, Escobar IE, Ho T, Lefkovith AJ, Latteri E, Haltaufderhyde KD, Dennis MK, Plowright L, Sviderskaya EV, Bennett DC, Oancea E, Marks MS. SLC45A2 protein stability and regulation of melanosome pH determine melanocyte pigmentation. Mol Biol Cell 2020; 31:2687-2702. [PMID: 32966160 PMCID: PMC7927184 DOI: 10.1091/mbc.e20-03-0200] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
SLC45A2 encodes a putative transporter expressed primarily in pigment cells. SLC45A2 mutations cause oculocutaneous albinism type 4 (OCA4) and polymorphisms are associated with pigmentation variation, but the localization, function, and regulation of SLC45A2 and its variants remain unknown. We show that SLC45A2 localizes to a cohort of mature melanosomes that only partially overlaps with the cohort expressing the chloride channel OCA2. SLC45A2 expressed ectopically in HeLa cells localizes to lysosomes and raises lysosomal pH, suggesting that in melanocytes SLC45A2 expression, like OCA2 expression, results in the deacidification of maturing melanosomes to support melanin synthesis. Interestingly, OCA2 overexpression compensates for loss of SLC45A2 expression in pigmentation. Analyses of SLC45A2- and OCA2-deficient mouse melanocytes show that SLC45A2 likely functions later during melanosome maturation than OCA2. Moreover, the light skin-associated SLC45A2 allelic F374 variant restores only moderate pigmentation to SLC45A2-deficient melanocytes due to rapid proteasome-dependent degradation resulting in lower protein expression levels in melanosomes than the dark skin-associated allelic L374 variant. Our data suggest that SLC45A2 maintains melanosome neutralization that is initially orchestrated by transient OCA2 activity to support melanization at late stages of melanosome maturation, and that a common allelic variant imparts reduced activity due to protein instability.
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Affiliation(s)
- Linh Le
- Department of Pathology & Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104.,Department of Pathology and Laboratory Medicine and Department of Physiology and.,Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Iliana E Escobar
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912
| | - Tina Ho
- Department of Pathology & Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104.,Department of Pathology and Laboratory Medicine and Department of Physiology and.,Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Ariel J Lefkovith
- Department of Pathology & Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104.,Department of Pathology and Laboratory Medicine and Department of Physiology and.,Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Emily Latteri
- Department of Pathology & Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104.,Department of Pathology and Laboratory Medicine and Department of Physiology and
| | - Kirk D Haltaufderhyde
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912
| | - Megan K Dennis
- Department of Pathology & Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104.,Department of Pathology and Laboratory Medicine and Department of Physiology and.,Biology Department, Marist College, Poughkeepsie, NY 12601
| | - Lynn Plowright
- Molecular & Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK
| | - Elena V Sviderskaya
- Molecular & Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK
| | - Dorothy C Bennett
- Molecular & Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK
| | - Elena Oancea
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912
| | - Michael S Marks
- Department of Pathology & Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104.,Department of Pathology and Laboratory Medicine and Department of Physiology and
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17
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Liu T, Yuan Y, Bai D, Qi Z, Yang L, Zhang T, Yang X, Li W, Wei A. Genetic variants and mutational spectrum of Chinese Hermansky–Pudlak syndrome patients. Pigment Cell Melanoma Res 2020; 34:111-121. [PMID: 32725903 DOI: 10.1111/pcmr.12916] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 07/13/2020] [Accepted: 07/21/2020] [Indexed: 01/09/2023]
Affiliation(s)
- Teng Liu
- Department of Dermatology Beijing Tongren Hospital Capital Medical University Beijing China
| | - Yefeng Yuan
- Beijing Key Laboratory for Genetics of Birth Defects Beijing Pediatric Research Institute Beijing Children's Hospital Capital Medical University Beijing China
- Genetics and Birth Defects Control Center National Center for Children's HealthBeijing China
- MOE Key Laboratory of Major Diseases in Children Capital Medical University Beijing China
| | - Dayong Bai
- Department of Ophthalmology National Center for Children's Health Beijing Children’s Hospital Capital Medical University Beijing China
| | - Zhan Qi
- Beijing Key Laboratory for Genetics of Birth Defects Beijing Pediatric Research Institute Beijing Children's Hospital Capital Medical University Beijing China
- Genetics and Birth Defects Control Center National Center for Children's HealthBeijing China
- MOE Key Laboratory of Major Diseases in Children Capital Medical University Beijing China
| | - Lin Yang
- Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing China
| | - Tianjiao Zhang
- Department of Dermatology Beijing Tongren Hospital Capital Medical University Beijing China
| | - Xiumin Yang
- Department of Dermatology Beijing Tongren Hospital Capital Medical University Beijing China
| | - Wei Li
- Beijing Key Laboratory for Genetics of Birth Defects Beijing Pediatric Research Institute Beijing Children's Hospital Capital Medical University Beijing China
- Genetics and Birth Defects Control Center National Center for Children's HealthBeijing China
- MOE Key Laboratory of Major Diseases in Children Capital Medical University Beijing China
| | - Aihua Wei
- Department of Dermatology Beijing Tongren Hospital Capital Medical University Beijing China
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18
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Chuan Z, Yan Y, Hao S, Zhang Q, Zhou B, Feng X, Wang X, Liu F, Zheng L, Cao Z, Ma X. Mutation Analysis of 63 Northwest Chinese Probands with Oculocutaneous Albinism. Curr Eye Res 2020; 46:140-143. [PMID: 32552135 DOI: 10.1080/02713683.2020.1781192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE To identify the mutational spectrum of 63 northwest Chinese probands with Oculocutaneous albinism (OCA), and identify correlations between phenotype and genotype. METHODS We recruited 63 clinically diagnosed with OCA patients in Gansu Provincial Maternal and Child Health Care Hospital. Mutation screening analysis was performed by direct sequencing and NGS-target sequencing to screen the variants on genes related to OCA. PolyPhen2 and PROVEN tools were used to predict the possible functional role of the novel variants. We assessed the pathogenicity of the novel mutations according to the clinical interpretation of genetic variants by ACMG/AMP 2015 guideline. RESULTS By molecular testing, 56 of the OCA probands were diagnosed as OCA 1, three were OCA 2 and one was OCA 4. The most common variants of TYR were c.929insC(33.7%), c.896 G > A(12.5%), c.832 C > T(9.6%).We found five novel variants of TYR that have not previously been reported. CONCLUSIONS We make an accurate diagnosis and classification for the OCA probands. Our result enlarged the mutational spectrum of TYR and SLC45A2. These findings could be useful for genetic counseling and gene diagnosis of OCA in Northwest of China.
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Affiliation(s)
- Zhang Chuan
- Graduate School of Peking Union Medical College , Beijing, China.,National Research Institute for Family Planning , Beijing, China.,Gansu Province Medical Genetics Center, Gansu Province Maternal and Child Health Care Hospital , Lanzhou, China
| | - Yousheng Yan
- National Research Institute for Family Planning , Beijing, China
| | - Shengju Hao
- Gansu Province Medical Genetics Center, Gansu Province Maternal and Child Health Care Hospital , Lanzhou, China
| | - Qinghua Zhang
- Gansu Province Medical Genetics Center, Gansu Province Maternal and Child Health Care Hospital , Lanzhou, China
| | - Bingbo Zhou
- Gansu Province Medical Genetics Center, Gansu Province Maternal and Child Health Care Hospital , Lanzhou, China
| | - Xuan Feng
- Gansu Province Medical Genetics Center, Gansu Province Maternal and Child Health Care Hospital , Lanzhou, China
| | - Xing Wang
- Gansu Province Medical Genetics Center, Gansu Province Maternal and Child Health Care Hospital , Lanzhou, China
| | - Furong Liu
- Gansu Province Medical Genetics Center, Gansu Province Maternal and Child Health Care Hospital , Lanzhou, China
| | - Lei Zheng
- Gansu Province Medical Genetics Center, Gansu Province Maternal and Child Health Care Hospital , Lanzhou, China
| | - Zongfu Cao
- Graduate School of Peking Union Medical College , Beijing, China.,National Research Institute for Family Planning , Beijing, China.,National Human Genetic Resources Center , Beijing, China
| | - Xu Ma
- Graduate School of Peking Union Medical College , Beijing, China.,National Research Institute for Family Planning , Beijing, China.,National Human Genetic Resources Center , Beijing, China
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Huizing M, Malicdan MCV, Wang JA, Pri-Chen H, Hess RA, Fischer R, O'Brien KJ, Merideth MA, Gahl WA, Gochuico BR. Hermansky-Pudlak syndrome: Mutation update. Hum Mutat 2020; 41:543-580. [PMID: 31898847 DOI: 10.1002/humu.23968] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/06/2019] [Accepted: 12/26/2019] [Indexed: 12/14/2022]
Abstract
Hermansky-Pudlak syndrome (HPS) is a group of 10 autosomal recessive multisystem disorders, each defined by the deficiency of a specific gene. HPS-associated genes encode components of four ubiquitously expressed protein complexes: Adaptor protein-3 (AP-3) and biogenesis of lysosome-related organelles complex-1 (BLOC-1) through -3. All individuals with HPS exhibit albinism and a bleeding diathesis; additional features occur depending on the defective protein complex. Pulmonary fibrosis is associated with AP-3 and BLOC-3 deficiency, immunodeficiency with AP-3 defects, and gastrointestinal symptoms are more prevalent and severe in BLOC-3 deficiency. Therefore, identification of the HPS subtype is valuable for prognosis, clinical management, and treatment options. The prevalence of HPS is estimated at 1-9 per 1,000,000. Here we summarize 264 reported and novel variants in 10 HPS genes and estimate that ~333 Puerto Rican HPS subjects and ~385 with other ethnicities are reported to date. We provide pathogenicity predictions for missense and splice site variants and list variants with high minor allele frequencies. Current cellular and clinical aspects of HPS are also summarized. This review can serve as a manifest for molecular diagnostics and genetic counseling aspects of HPS.
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Affiliation(s)
- Marjan Huizing
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - May C V Malicdan
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Jennifer A Wang
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Hadass Pri-Chen
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland.,Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Richard A Hess
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Roxanne Fischer
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Kevin J O'Brien
- Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Melissa A Merideth
- Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - William A Gahl
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Bernadette R Gochuico
- Human Biochemical Genetics Section, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
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20
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Wu W, Lin K, Yang Y, Dong Z, Zhang T, Lei W, Yang W, Yang Z. A novel mutation causes Hermansky-Pudlak syndrome type 4 with pulmonary fibrosis in 2 siblings from China. Medicine (Baltimore) 2019; 98:e16899. [PMID: 31415434 PMCID: PMC6831253 DOI: 10.1097/md.0000000000016899] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive multisystem disorder characterized by oculocutaneous albinism (OCA) and bleeding diathesis, although it displays both genetic and phenotypic heterogeneity. Several genetic subtypes of HPS have been identified in human; however, the characterizations of HPS type 4 (HPS-4) genotype and phenotype remain unclear. This study was aimed to identify gene mutation responsible for HPS-4 with pulmonary fibrosis (PF).Two Chinese siblings in their 50 s afflicted with OCA and progressive dyspnea were recruited and underwent clinical and genetic examinations. In both patients, chest high-resolution computerized tomography showed severe interstitial PF in bilateral lung fields, and the pulmonary function test indicated restrictive lung disease. A novel homozygous frameshift mutation (NM_022081: c.630dupC; p.A211fs) in the HPS4 gene was identified by whole-exome sequencing analysis followed by Sanger DNA sequencing, and it segregated with the phenotypes. The c.630dupC mutation was not found in unaffected healthy controls. The patients were considered as HPS-4 with interstitial PF and eventually died of respiratory failure.This is the first report on the genotype and clinical phenotype of HPS-4 in China. Our results demonstrate the association between a novel frameshift mutation in HPS4 and severe PF with poor prognosis in HPS is presented.
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Affiliation(s)
- Wenjuan Wu
- School of Pharmaceutical Science and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University
- The second affiliated hospital of Kunming Medical University, 374 Dianmian Avenue, Kunming, China
| | - Keqin Lin
- Department of Medical Genetics, Institute of Medical Biology, Peking Union Medical University & Chinese Academy of Medical Sciences
| | - Yanni Yang
- The second affiliated hospital of Kunming Medical University, 374 Dianmian Avenue, Kunming, China
| | - ZhaoXing Dong
- The second affiliated hospital of Kunming Medical University, 374 Dianmian Avenue, Kunming, China
| | - Tao Zhang
- The second affiliated hospital of Kunming Medical University, 374 Dianmian Avenue, Kunming, China
| | - Wen Lei
- The second affiliated hospital of Kunming Medical University, 374 Dianmian Avenue, Kunming, China
| | - Weimin Yang
- School of Pharmaceutical Science and Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University
| | - Zhaoqing Yang
- Department of Medical Genetics, Institute of Medical Biology, Peking Union Medical University & Chinese Academy of Medical Sciences
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21
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Luo D, Linpeng S, Zeng L, Tan H, Li Z, Wu L. Molecular genetic study of 59 Chinese Oculocutaneous albinism families. Eur J Med Genet 2019; 62:103709. [PMID: 31229681 DOI: 10.1016/j.ejmg.2019.103709] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 04/24/2019] [Accepted: 06/19/2019] [Indexed: 12/11/2022]
Abstract
Oculocutaneous albinism is an autosomal recessive disorder characterized by either a complete lack of or reduction in melanin biosynthesis in the skin, hair, and eyes. The aim of the present study was to identify the molecular basis for 59 Chinese OCA families. In this study, compound heterozygous or homozygous pathogenic variants were found in 53 families, 4 families possessed only one heterozygous variant, and the pathogenic variants of 2 families remain undiscovered by using Sanger sequencing, whole exome sequencing and multiplex ligation-dependent probe amplification. We have identified a total of 55 variants including 21 novel variants in TYR, OCA2, SLC45A2, SLC24A5, and HPS1. The 21 novel variants include 11 missense changes, 4 nonsense changes, 2 splice site changes, 1 frameshift and 3 gross deletions. Forty-six variants including 14 novel variants were segregated with the phenotype in 37 families. We conducted RT-PCR of the novel splicing site variant (c.399-14G > A) of HPS1 and verified that the variant would result in the inclusion of 12 bp of intronic material in exon 6 of HPS1. The results of platelet whole mount electron microscopy further confirmed the diagnosis of HPS1. These novel variants identified in our study expand the mutational spectrum of the disease, which contributes to prenatal diagnosis and genetic counselling.
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Affiliation(s)
- Dan Luo
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Siyuan Linpeng
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Lanlan Zeng
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Hu Tan
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Zhuo Li
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Lingqian Wu
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China.
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22
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Lin Y, Chen X, Yang Y, Che F, Zhang S, Yuan L, Wu Y. Mutational Analysis of TYR, OCA2, and SLC45A2 Genes in Chinese Families with Oculocutaneous Albinism. Mol Genet Genomic Med 2019; 7:e00687. [PMID: 31199599 PMCID: PMC6625147 DOI: 10.1002/mgg3.687] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 02/24/2019] [Accepted: 03/06/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Oculocutaneous albinism (OCA) is a group of heterogeneous autosomal recessive genetic disorder of melanin synthesis results in hypopigmented hair, skin, and eyes. OCA type 1, OCA type 2, and OCA type 4, which are respectively caused by mutations in TYR, OCA2, and SLC45A2 have high morbidity rates in Asia. METHODS TYR, OCA2, and SLC45A2 mutation analysis was carried out on 18 nonconsanguineous OCA patients and four fetuses were included for prenatal diagnose. Three genes of all individuals were amplified by polymerase chain reaction and examined by Sanger sequencing. The pathogenicity of the detected mutations were analyzed by Mutation Taster, PolyPhen 2, and SIFT software, and the conservation of the substituted amino acids were analyzed by MEGA software. RESULTS Eleven TYR mutations, three OCA2 mutations, and two SLC45A2 mutations were identified in 14 OCA type 1 patients, two OCA type 2 patients, and two OCA type 4 patients. c.1021A>G, p.R341G in TYR, c.1096_1104del, p.V366*, and c.1079C>T, p.S360F in OCA2 were novel. One of the four fetuses carried compound heterozygous mutation of TYR and became spontaneous abortion, the other three carried no mutations and appeared normal at birth. CONCLUSION In this study, specific clinical characteristics of OCA patients were described. Three novel pathogenic mutations were identified which will enrich the mutation spectrum of OCA, and the prenatal genetic screening in fetus at risk of OCA can provide vital information for genetic counseling.
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Affiliation(s)
- Ye Lin
- The General Hospital of the People's Liberation Army, Beijing, P.R. China
| | - Xihui Chen
- Department of Biochemistry and Molecular Biology, Center for DNA Typing, Air Force Medical University, Xi'an, Shaanxi, P.R. China
| | - Ying Yang
- Shaanxi Institute of Pediatric Diseases, Xi'an Children's Hospital, Xi'an, Shaanxi, P.R. China
| | - Fengyu Che
- Shaanxi Institute of Pediatric Diseases, Xi'an Children's Hospital, Xi'an, Shaanxi, P.R. China
| | - Sijia Zhang
- Department of Biochemistry and Molecular Biology, Center for DNA Typing, Air Force Medical University, Xi'an, Shaanxi, P.R. China
| | - Lijuan Yuan
- Department of Biochemistry and Molecular Biology, Center for DNA Typing, Air Force Medical University, Xi'an, Shaanxi, P.R. China.,Department of General Surgery, Tangdu Hospital, Air Force Medical University, Xi'an, Shaanxi, P.R. China
| | - Yuanming Wu
- Department of Biochemistry and Molecular Biology, Center for DNA Typing, Air Force Medical University, Xi'an, Shaanxi, P.R. China
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23
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Zhong Z, Gu L, Zheng X, Ma N, Wu Z, Duan J, Zhang J, Chen J. Comprehensive analysis of spectral distribution of a large cohort of Chinese patients with non-syndromic oculocutaneous albinism facilitates genetic diagnosis. Pigment Cell Melanoma Res 2019; 32:672-686. [PMID: 31077556 PMCID: PMC6852118 DOI: 10.1111/pcmr.12790] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 03/31/2019] [Accepted: 05/05/2019] [Indexed: 12/25/2022]
Abstract
Non-syndromic oculocutaneous albinism (nsOCA) is a group of genetically heterogeneous autosomal recessive disorders with complete lack or decrease pigmentation in skin, hair, and eyes. TYR, OCA2, TYRP1, SLC45A2, SLC24A5, and LRMDA were reported to cause OCA1-4 and OCA6-7, respectively. By sequencing all the known nsOCA genes in 114 unrelated Chinese nsOCA patients combined with In silico analyses, splicing assay, and classification of variants according to the standards and guidelines of American College of Medical Genetics and Genomics, we detected seventy-one different OCA-causing variants separately in TYR, OCA2, SLC45A2, and SLC24A5, including thirty-one novel variants (13 in TYR, 11 in OCA2, and 7 in SLC45A2). This study shows that OCA1 is the most common (75/114) and OCA2 ranks the second most common (16/114) in Chinese. 99 patients of our cohort were caused by variants of all the known nsOCA genes. Cutaneous phenotypes of OCA1, OCA2, and OCA4 patients were shown in this study. The second OCA6 case in China was identified here. These data expand the spectrum of OCA variants as well phenotype and facilitate clinical implement of Chinese OCA patients.
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Affiliation(s)
- Zilin Zhong
- Department of Pediatrics of Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Medical Genetics, Tongji University School of Medicine, Shanghai, China.,Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
| | - Li Gu
- Department of Pediatrics of Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Xiujie Zheng
- Department of Pediatrics of Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Medical Genetics, Tongji University School of Medicine, Shanghai, China
| | - Nengjun Ma
- Department of Pediatrics of Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Medical Genetics, Tongji University School of Medicine, Shanghai, China
| | - Zehua Wu
- Department of Pediatrics of Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Medical Genetics, Tongji University School of Medicine, Shanghai, China
| | - Juan Duan
- Department of Auxiliary Reproductive, Jiujiang Maternal and Child Health Hospital, Jiujiang, China
| | - Jun Zhang
- Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
| | - Jianjun Chen
- Department of Pediatrics of Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Medical Genetics, Tongji University School of Medicine, Shanghai, China.,Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
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24
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Liu Z, Shan H, Chen S, Chen M, Zhang Q, Lai L, Li Z. Improved base editor for efficient editing in GC contexts in rabbits with an optimized AID-Cas9 fusion. FASEB J 2019; 33:9210-9219. [PMID: 31071267 DOI: 10.1096/fj.201900476rr] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Cytidine base editors, which are composed of a cytidine deaminase fused to clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9) nickase, enable the efficient conversion of the C·G base pair to T·A in various organisms. However, the currently used rat apolipoprotein B mRNA-editing enzyme, catalytic polypeptide 1(rA1)-based BE3 is often inefficient in target Cs that are immediately downstream of a G (GC context). Here, we observed that, with an 11-nt editing window, an optimized activation-induced cytidine deaminase (AID)-Cas9 fusion can efficiently convert C to T in a variety of sequence contexts in rabbits. Strikingly, the enhanced AID-Cas9 fusion (eAID-BE4max) has significant effectiveness of inducing Tyr p.R299H mutation in GC contexts (from 16.67 to 83.33%) in comparison with BE3 in founder rabbits. Furthermore, the engineered AID-Cas9 variants were produced with reduced bystander activity [eAID (N51G)-BE4max] and increased genome-targeting scope (eAID-NG-BE4max). Overall, this work provides a series of improved tools that were generated using optimized AID-Cas9 fusions and associated engineered variants that can be used for efficient and versatile C-to-T base editing, especially in GC contexts.-Liu, Z., Shan, H., Chen, S., Chen, M., Zhang, Q., Lai, L., Li, Z. Improved base editor for efficient editing in GC contexts in rabbits with an optimized AID-Cas9 fusion.
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Affiliation(s)
- Zhiquan Liu
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun, China
| | - Huanhuan Shan
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun, China
| | - Siyu Chen
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun, China
| | - Mao Chen
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun, China
| | - Quanjun Zhang
- Guangzhou Regenerative Medicine and Health Guang Dong Laboratory (GRMH-GDL), Guangzhou, China
| | - Liangxue Lai
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun, China.,Guangzhou Regenerative Medicine and Health Guang Dong Laboratory (GRMH-GDL), Guangzhou, China
| | - Zhanjun Li
- Key Laboratory of Zoonosis Research, Ministry of Education, College of Animal Sciences, Jilin University, Changchun, China
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25
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Wei A, Yuan Y, Qi Z, Liu T, Bai D, Zhang Y, Yu J, Yang L, Yang X, Li W. Instability of BLOC‐2 and BLOC‐3 in Chinese patients with Hermansky‐Pudlak syndrome. Pigment Cell Melanoma Res 2018; 32:373-380. [PMID: 30387913 DOI: 10.1111/pcmr.12748] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 08/30/2018] [Accepted: 10/21/2018] [Indexed: 01/06/2023]
Affiliation(s)
- Aihua Wei
- Department of Dermatology, Beijing Tongren Hospital Capital Medical University Beijing China
| | - Yefeng Yuan
- Beijing Key Laboratory for Genetics of Birth Defects; MOE Key Laboratory of Major Diseases in Children; Center for Medical Genetics, Beijing Pediatric Research Institute; Beijing Children’s HospitalCapital Medical University; National Center for Children's Health Beijing China
| | - Zhan Qi
- Beijing Key Laboratory for Genetics of Birth Defects; MOE Key Laboratory of Major Diseases in Children; Center for Medical Genetics, Beijing Pediatric Research Institute; Beijing Children’s HospitalCapital Medical University; National Center for Children's Health Beijing China
| | - Teng Liu
- Department of Dermatology, Beijing Tongren Hospital Capital Medical University Beijing China
| | - Dayong Bai
- Department of Ophthalmology, Beijing Children’s Hospital Capital Medical University Beijing China
| | - Yingzi Zhang
- Shunyi Women and Children’s Hospital of Beijing Children’s Hospital Beijing China
| | - Jiaying Yu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing China
| | - Lin Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing China
| | - Xiumin Yang
- Department of Dermatology, Beijing Tongren Hospital Capital Medical University Beijing China
| | - Wei Li
- Beijing Key Laboratory for Genetics of Birth Defects; MOE Key Laboratory of Major Diseases in Children; Center for Medical Genetics, Beijing Pediatric Research Institute; Beijing Children’s HospitalCapital Medical University; National Center for Children's Health Beijing China
- Shunyi Women and Children’s Hospital of Beijing Children’s Hospital Beijing China
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26
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Farney SK, Dolinska MB, Sergeev YV. Dynamic analysis of human tyrosinase intra-melanosomal domain and mutant variants to further understand oculocutaneous albinism type 1. ACTA ACUST UNITED AC 2018; 7:621-632. [PMID: 30868138 PMCID: PMC6411056 DOI: 10.15406/japlr.2018.07.00293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Human tyrosinase (Tyr) is a Type I membrane glycoprotein that is the rate-limiting enzyme for controlling the production of melanin pigment in melanosomes. Currently, ~300 Tyr mutations are known to be involved in the genetic disease oculocutaneous albinism type 1 (OCA1), which exists in two forms, OCA1A and OCA1B. OCA1A is caused by a full loss of Tyr enzymatic activity, resulting in the absence of pigment in the skin, hair, and eyes, while OCA1B has reduced Tyr activity and pigment. Here, we used molecular modeling to try to understand the role of genetic changes at the protein level in inherited disease. The significant part of Tyr intra-melanosomal domain and five OCA1 mutant variants were built by homology modeling, glycosylated in silico, and refined using molecular dynamics in water. The modeling confirmed experimental results that N347 and N371 glycosylation is vital for protein stability. The changes caused by the T373K mutation indicate a significant impact on protein structure, as expected for OCA1A. In addition, evaluation of free energy changes in OCA1B mutants showed a strong association with the changes observed in our unfolding/refolding experiments in vitro. In conclusion, our results could be useful for understanding the role of OCA1 mutant variants in melanin pigment production, in silico searching for inhibitors and activators of tyrosinase activity, and genotype-to- phenotype analysis in OCA1.
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Affiliation(s)
- S Katie Farney
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, USA
| | - Monika B Dolinska
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, USA
| | - Yuri V Sergeev
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, USA
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27
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Wang Y, Zhou YF, Shen N, Zhu YW, Tan K, Wang X. Identification of a Homozygous Missense Mutation in the TYR Gene in a Chinese Family with OCA1. Curr Med Sci 2018; 38:932-936. [PMID: 30341532 DOI: 10.1007/s11596-018-1965-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 09/20/2018] [Indexed: 12/28/2022]
Abstract
Oculocutaneous albinism (OCA) is an autosomal recessive pigmentation abnormality, characterized by variable hair, skin, and ocular hypopigmentation. OCA1 is the most frequent subtype of OCA, caused by mutations in the tyrosinase gene (TYR). In this study, we investigated the genetic mutation of a Chinese family with a female OCA patient who came for genetic counseling before pregnancy. Complete physical examination was performed, and DNA from blood samples was collected from the family members. Mutations of TYR, OCA2, and SLC45A2 genes were examined in the proband, and verified in her parents by Sanger sequencing. Large deletion or duplication of TYR and OCA2 genes was detected by multiplex ligation-dependent probe amplification (MLPA). A homozygous TYR c.307T>C (p.Cys103Arg) missense mutation was identified in the proband, and both parents were heterozygous carriers. No large deletion or duplication was found in the proband. This mutation was absent in 1000G, ExAC, or HGMD database, and multiple lines of in silico tools supported a deleterious effect. These results suggest that TYR c.307T>C mutation might be responsible for OCA1, and our study further expands the mutation spectrum of OCA1 in the Chinese population.
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Affiliation(s)
- Yan Wang
- Department of Neurosurgery, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yi-Fan Zhou
- Reproductive Medicine Center, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Na Shen
- Department of Laboratory Medicine, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yao-Wu Zhu
- Department of Laboratory Medicine, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Kun Tan
- Department of Infection Control, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Xiong Wang
- Department of Laboratory Medicine, Huazhong University of Science and Technology, Wuhan, 430030, China.
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28
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Computational analysis of deleterious SNPs of SLC45A2 involved in oculocutaneous albinism type 4. GENE REPORTS 2018. [DOI: 10.1016/j.genrep.2018.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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29
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Sun W, Shen Y, Shan S, Han L, Li Y, Zhou Z, Zhong Z, Chen J. Identification of TYR mutations in patients with oculocutaneous albinism. Mol Med Rep 2018; 17:8409-8413. [PMID: 29658579 DOI: 10.3892/mmr.2018.8881] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 08/01/2017] [Indexed: 11/06/2022] Open
Abstract
Oculocutaneous albinism (OCA) is a set of autosomal recessive disorders characterized by hypopigmented hair, skin and eyes. Homozygous or compound heterozygous mutations in the tyrosinase (TYR) gene can cause OCA1, which is the most common and severe subtype of albinism. In the present study, 17 patients with non‑syndromic OCA were enrolled from eight provinces of China and were non‑consanguineous, with the exception of Patient 4000301. Total genomic DNA was isolated from peripheral blood. Screening was performed for the whole exons and their flanking regions of the TYR gene using Sanger sequencing and the pathogenicity of variants was predicted using in silico analysis. In total, 12 TYR mutations were identified in 10 patients, respectively. Of these, two patients carried homozygous mutations and eight patients carried compound heterozygous mutations. Among the 12 TYR mutations, two missense mutations c.1198T>G (p.W400G) and c.819G>T (p.Q273H) were novel. The results of the present study expand the mutation spectrum of the TYR gene, which may further assist in the prenatal examination and genetic diagnosis of OCA.
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Affiliation(s)
- Wan Sun
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji Eye Institute, Tongji University School of Medicine, Shanghai 200092, P.R. China
| | - Yanjie Shen
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji Eye Institute, Tongji University School of Medicine, Shanghai 200092, P.R. China
| | - Shan Shan
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China
| | - Liyun Han
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji Eye Institute, Tongji University School of Medicine, Shanghai 200092, P.R. China
| | - Yang Li
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji Eye Institute, Tongji University School of Medicine, Shanghai 200092, P.R. China
| | - Zheng Zhou
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, P.R. China
| | - Zilin Zhong
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji Eye Institute, Tongji University School of Medicine, Shanghai 200092, P.R. China
| | - Jianjun Chen
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji Eye Institute, Tongji University School of Medicine, Shanghai 200092, P.R. China
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30
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Wang X, Zhu Y, Shen N, Peng J, Wang C, Liu H, Lu Y. Mutation analysis of a Chinese family with oculocutaneous albinism. Oncotarget 2018; 7:84981-84988. [PMID: 27829221 PMCID: PMC5356713 DOI: 10.18632/oncotarget.13109] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 10/22/2016] [Indexed: 11/25/2022] Open
Abstract
Oculocutaneous albinism (OCA) is an autosomal recessive disorder characterized by either complete lack of or a reduction in melanin biosynthesis in the skin, hair, and eyes. OCA1, the most common and severe type, is caused by mutations in the tyrosinase (TYR) gene. In this study, we report a Chinese family with two members affected by OCA. Blood samples were collected from all family members. Genomic DNA was isolated from blood leukocytes, and all coding exons and adjacent intronic sequences of the TYR gene were examined for mutation analysis using polymerase chain reaction (PCR)-based sequencing. A pedigree chart was drawn, and clinical examinations and paraclinical tests were performed. Compound heterozygous mutations in TYR (c.832C>T and c.929_930insC, which resulted in p.Arg278* and p.Arg311Lysfs*7, respectively) were identified in the two patients with milky skin, white hair, photophobia, and reduced visual acuity, while other family members only carried one of two heterozygous mutations. In addition, a homozygous missense mutation c.814G>A (p.Glu272Lys) in the solute carrier family 45 member 2 (SLC45A2) gene was found in both patients and unaffected family members, suggesting that this may not be a causative mutation. The findings of this study expand the mutational spectrum of OCA. Compound heterozygous mutations (c.832C>T and c.929_930insC) in the TYR gene may be responsible for partial clinical manifestations of OCA, while the homozygous missense mutation c.814G>A (p.Glu272Lys) in the SLC45A2 gene may not be associated with OCA.
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Affiliation(s)
- Xiong Wang
- Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yaowu Zhu
- Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Na Shen
- Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jing Peng
- Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Chunyu Wang
- Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Haiyi Liu
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yanjun Lu
- Department of Laboratory Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
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Qiu B, Ma T, Peng C, Zheng X, Yang J. Identification of Five Novel Variants in Chinese Oculocutaneous Albinism by Targeted Next-Generation Sequencing. Genet Test Mol Biomarkers 2018; 22:252-258. [PMID: 29437493 DOI: 10.1089/gtmb.2017.0211] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The diagnosis of oculocutaneous albinism (OCA) is established using clinical signs and symptoms. OCA is, however, a highly genetically heterogeneous disease with mutations identified in at least nineteen unique genes, many of which produce overlapping phenotypic traits. Thus, differentiating genetic OCA subtypes for diagnoses and genetic counseling is challenging, based on clinical presentation alone, and would benefit from a comprehensive molecular diagnostic. AIM To develop and validate a more comprehensive, targeted, next-generation-sequencing-based diagnostic for the identification of OCA-causing variants. MATERIALS AND METHODS The genomic DNA samples from 28 OCA probands were analyzed by targeted next-generation sequencing (NGS), and the candidate variants were confirmed through Sanger sequencing. RESULTS We observed mutations in the TYR, OCA2, and SLC45A2 genes in 25/28 (89%) patients with OCA. We identified 38 pathogenic variants among these three genes, including 5 novel variants: c.1970G>T (p.Gly657Val), c.1669A>C (p.Thr557Pro), c.2339-2A>C, and c.1349C>G (p.Thr450Arg) in OCA2; c.459_470delTTTTGCTGCCGA (p.Ala155_Phe158del) in SLC45A2. CONCLUSION Our findings expand the mutational spectrum of OCA in the Chinese population, and the assay we developed should be broadly useful as a molecular diagnostic, and as an aid for genetic counseling for OCA patients.
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Affiliation(s)
- Biyuan Qiu
- 1 Medical Technology College, Chengdu University of Traditional Chinese Medicine of China , Chengdu, Sichuan, P.R. China
| | - Tao Ma
- 2 Prenatal Diagnosis Center, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital , Chengdu, Sichuan, P.R. China .,3 Department of Gynecology & Obstetrics, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital , Chengdu, Sichuan, P.R. China
| | - Chunyan Peng
- 4 School of Medicine, University of Electronic Science and Technology of China , Chengdu, Sichuan, P.R. China
| | - Xiaoqin Zheng
- 1 Medical Technology College, Chengdu University of Traditional Chinese Medicine of China , Chengdu, Sichuan, P.R. China
| | - Jiyun Yang
- 2 Prenatal Diagnosis Center, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital , Chengdu, Sichuan, P.R. China .,4 School of Medicine, University of Electronic Science and Technology of China , Chengdu, Sichuan, P.R. China .,5 Sichuan Provincial Key Laboratory for Human Disease Gene Study, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital , Chengdu, Sichuan, P.R. China
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Fábos B, Farkas K, Tóth L, Sulák A, Tripolszki K, Tihanyi M, Németh R, Vas K, Csoma Z, Kemény L, Széll M, Nagy N. Delineating the genetic heterogeneity of OCA in Hungarian patients. Eur J Med Res 2017. [PMID: 28629449 PMCID: PMC5477306 DOI: 10.1186/s40001-017-0262-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Oculocutaneous albinism (OCA) is a clinically and genetically heterogenic group of pigmentation abnormalities characterized by variable hair, skin, and ocular hypopigmentation. Six known genes and a locus on human chromosome 4q24 have been implicated in the etiology of isolated OCA forms (OCA 1-7). METHODS The most frequent OCA types among Caucasians are OCA1, OCA2, and OCA4. We aimed to investigate genes responsible for the development of these OCA forms in Hungarian OCA patients (n = 13). Mutation screening and polymorphism analysis were performed by direct sequencing on TYR, OCA2, SLC45A2 genes. RESULTS Although the clinical features of the investigated Hungarian OCA patients were identical, the molecular genetic data suggested OCA1 subtype in eight cases and OCA4 subtype in two cases. The molecular diagnosis was not clearly identifiable in three cases. In four patients, two different heterozygous known pathogenic or predicted to be pathogenic mutations were present. Seven patients had only one pathogenic mutation, which was associated with non-pathogenic variants in six cases. In two patients no pathogenic mutation was identified. CONCLUSIONS Our results suggest that the concomitant screening of the non-pathogenic variants-which alone do not cause the development of OCA, but might have clinical significance in association with a pathogenic variant-is important. Our results also show significant variation in the disease spectrum compared to other populations. These data also confirm that the concomitant analysis of OCA genes is critical, providing new insights to the phenotypic diversity of OCA and expanding the mutation spectrum of OCA genes in Hungarian patients.
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Affiliation(s)
- Beáta Fábos
- Mór Kaposi Teaching Hospital of the Somogy County, Kaposvár, Hungary
| | - Katalin Farkas
- MTA-SZTE Dermatological Research Group, University of Szeged, Szeged, Hungary
| | - Lola Tóth
- Department of Medical Genetics, University of Szeged, 4 Somogyi Bela Street, 6720, Szeged, Hungary
| | - Adrienn Sulák
- Department of Medical Genetics, University of Szeged, 4 Somogyi Bela Street, 6720, Szeged, Hungary
| | - Kornélia Tripolszki
- Department of Medical Genetics, University of Szeged, 4 Somogyi Bela Street, 6720, Szeged, Hungary
| | - Mariann Tihanyi
- Genetic Laboratory, Hospital of Zala County, Zalaegerszeg, Hungary
| | - Réka Németh
- Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
| | - Krisztina Vas
- Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
| | - Zsanett Csoma
- Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
| | - Lajos Kemény
- MTA-SZTE Dermatological Research Group, University of Szeged, Szeged, Hungary.,Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
| | - Márta Széll
- MTA-SZTE Dermatological Research Group, University of Szeged, Szeged, Hungary.,Department of Medical Genetics, University of Szeged, 4 Somogyi Bela Street, 6720, Szeged, Hungary
| | - Nikoletta Nagy
- MTA-SZTE Dermatological Research Group, University of Szeged, Szeged, Hungary. .,Department of Medical Genetics, University of Szeged, 4 Somogyi Bela Street, 6720, Szeged, Hungary. .,Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary.
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Lu Q, Yuan L, Xu H, Huang X, Yang Z, Yi J, Ni B, Chen Y, Deng H. Identification of a missense mutation in the tyrosinase gene in a Chinese family with oculocutaneous albinism type 1. Mol Med Rep 2017; 15:1426-1430. [PMID: 28112372 DOI: 10.3892/mmr.2017.6137] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 12/07/2016] [Indexed: 11/05/2022] Open
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Wei A, Yuan Y, Bai D, Ma J, Hao Z, Zhang Y, Yu J, Zhou Z, Yang L, Yang X, Li L, Li W. NGS-based 100-gene panel of hypopigmentation identifies mutations in Chinese Hermansky-Pudlak syndrome patients. Pigment Cell Melanoma Res 2016; 29:702-706. [PMID: 27593200 DOI: 10.1111/pcmr.12534] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 08/22/2016] [Indexed: 01/22/2023]
Abstract
Hermansky-Pudlak syndrome (HPS) is a rare recessive disorder characterized by hypopigmentation, bleeding diathesis, and other symptoms due to multiple defects in lysosome-related organelles. Ten HPS subtypes have been identified with mutations in HPS1 to HPS10. Only four patients with HPS-1 have been reported in Chinese population. Using next-generation sequencing (NGS), we have screened 100 hypopigmentation genes and identified four HPS-1, two HPS-3, one HPS-5, and three HPS-6 in Chinese HPS patients with typical ocular or oculocutaneous albinism and the absence of platelet dense granules together with other variable phenotypes. All these patients except one homozygote were compound heterozygotes. Among these mutations, 14 were previously unreported alleles (four in HPS1, three in HPS3, two in HPS5, five in HPS6). Our results demonstrate the feasibility and utility of NGS-based panel diagnostics for HPS. Genotyping of HPS subtypes is a prerequisite for intervention of subtype-specific symptoms.
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Affiliation(s)
- Aihua Wei
- Department of Dermatology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yefeng Yuan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics & Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Dayong Bai
- Department of Ophthalmology, Beijing Childrens Hospital, Capital Medical University, Beijing, China
| | - Jing Ma
- Center for Medical Genetics, Beijing Childrens Hospital, Capital Medical University, Beijing Pediatric Research Institute, MOE Key Laboratory of Major Diseases in Children, Beijing, China
| | - Zhenhua Hao
- Center for Medical Genetics, Beijing Childrens Hospital, Capital Medical University, Beijing Pediatric Research Institute, MOE Key Laboratory of Major Diseases in Children, Beijing, China
| | - Yingzi Zhang
- Department of Dermatology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Jiaying Yu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics & Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Zhiyong Zhou
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics & Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Lin Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics & Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Xiumin Yang
- Department of Dermatology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Li Li
- Department of Ophthalmology, Beijing Childrens Hospital, Capital Medical University, Beijing, China
| | - Wei Li
- Center for Medical Genetics, Beijing Childrens Hospital, Capital Medical University, Beijing Pediatric Research Institute, MOE Key Laboratory of Major Diseases in Children, Beijing, China.,Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, China
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Khordadpoor-Deilamani F, Akbari MT, Karimipoor M, Javadi GR. Homozygosity mapping in albinism patients using a novel panel of 13 STR markers inside the nonsyndromic OCA genes: introducing 5 novel mutations. J Hum Genet 2016; 61:373-9. [DOI: 10.1038/jhg.2015.167] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 11/16/2015] [Accepted: 11/26/2015] [Indexed: 02/06/2023]
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Wei AH, Zang DJ, Zhang Z, Yang XM, Li W. Prenatal Genotyping of Four Common Oculocutaneous Albinism Genes in 51 Chinese Families. J Genet Genomics 2015; 42:279-86. [DOI: 10.1016/j.jgg.2015.05.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 05/17/2015] [Accepted: 05/18/2015] [Indexed: 11/28/2022]
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Mutational Analysis of the TYR and OCA2 Genes in Four Chinese Families with Oculocutaneous Albinism. PLoS One 2015; 10:e0125651. [PMID: 25919014 PMCID: PMC4412409 DOI: 10.1371/journal.pone.0125651] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Accepted: 03/17/2015] [Indexed: 11/19/2022] Open
Abstract
Background Oculocutaneous albinism (OCA) is an autosomal recessive disorder. The most common type OCA1 and OCA2 are caused by homozygous or compound heterozygous mutations in the tyrosinase gene (TYR) and OCA2 gene, respectively. Objective The purpose of this study was to evaluate the molecular basis of oculocutaneous albinism in four Chinese families. Patients and Methods Four non-consanguineous OCA families were included in the study. The TYR and OCA2 genes of all individuals were amplified by polymerase chain reaction (PCR), sequenced and compared with a reference database. Results Four patients with a diagnosis of oculocutaneous albinism, presented with milky skin, white or light brown hair and nystagmus. Genetic analyses demonstrated that patient A was compound heterozygous for c.1037-7T.A, c.1037-10_11delTT and c.1114delG mutations in the TYR gene; patient B was heterozygous for c.593C>T and c.1426A>G mutations in the OCA2 gene, patients C and D were compound heterozygous mutations in the TYR gene (c.549_550delGT and c.896G>A, c.832C>T and c.985T>C, respectively). The heterozygous c.549_550delGT and c.1114delG alleles in the TYR gene were two novel mutations. Interestingly, heterozygous members in these pedigrees who carried c.1114delG mutations in the TYR gene or c.1426A>G mutations in the OCA2 gene presented with blond or brown hair and pale skin, but no ocular disorders when they were born; the skin of these patients accumulated pigment over time and with sun exposure. Conclusion This study expands the mutation spectrum of oculocutaneous albinism. It is the first time, to the best of our knowledge, to report that c.549_550delGT and c.1114delG mutations in the TYR gene were associated with OCA. The two mutations (c.1114delG in the TYR gene and c.1426A>G in the OCA2 gene) may be responsible for partial clinical manifestations of OCA.
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Abstract
Oculocutaneous albinism (OCA) is a heterogeneous autosomal recessive genetic disorder that affects melanin synthesis. OCA results in reduced or absent pigmentation in the hair, skin and eyes. Type 1 OCA (OCA1) is the result of tyrosinase (TYR) gene mutations and is a severe disease type. This study investigated TYR mutations in a Chinese cohort with OCA1. This study included two parts: patient genetic study and prenatal genetic diagnosis. A total of 30 OCA1 patients were subjected to TYR gene mutation analysis. Ten pedigrees were included for prenatal genetic diagnosis. A total of 100 unrelated healthy Chinese individuals were genotyped for controls. The coding sequence and the intron/exon junctions of TYR were analysed by bidirectional DNA sequencing. In this study, 20 mutations were identified, four of which were novel. Of these 30 OCA1 patients, 25 patients were TYR compound heterozygous; two patients carried homozygous TYR mutations; and three were heterozygous. Among the ten prenatally genotyped fetuses, three fetuses carried compound heterozygous mutations and seven carried no mutation or only one mutant allele of TYR and appeared normal at birth. In conclusion, we identified four novel TYR mutations and showed that molecular-based prenatal screening to detect TYR mutations in a fetus at risk for OCA1 provided essential information for genetic counselling of couples at risk.
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Ghodsinejad Kalahroudi V, Kamalidehghan B, Arasteh Kani A, Aryani O, Tondar M, Ahmadipour F, Chung LY, Houshmand M. Two novel tyrosinase (TYR) gene mutations with pathogenic impact on oculocutaneous albinism type 1 (OCA1). PLoS One 2014; 9:e106656. [PMID: 25216246 PMCID: PMC4162572 DOI: 10.1371/journal.pone.0106656] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 08/06/2014] [Indexed: 11/19/2022] Open
Abstract
Oculocutaneous albinism (OCA) is a heterogeneous group of autosomal recessive disorders resulting from mutations of the tyrosinase (TYR) gene and presents with either complete or partial absence of pigment in the skin, hair and eyes due to a defect in an enzyme involved in the production of melanin. In this study, mutations in the TYR gene of 30 unrelated Iranian OCA1 patients and 100 healthy individuals were examined using PCR-sequencing. Additionally, in order to predict the possible effects of new mutations on the structure and function of tyrosinase, these mutations were analyzed by SIFT, PolyPhen and I-Mutant 2 software. Here, two new pathogenic p.C89S and p.H180R mutations were detected in two OCA1 patients. Moreover, the R402Q and S192Y variants, which are common non-pathogenic polymorphisms, were detected in 17.5% and 35% of the patients, respectively. The outcome of this study has extended the genotypic spectrum of OCA1 patients, which paves the way for more efficient carrier detection and genetic counseling.
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Affiliation(s)
- Vadieh Ghodsinejad Kalahroudi
- Department of Biology, Kharazmi University, Tehran, Iran
- Department of Medical Genetics, Special Medical Center, Tehran, Iran
| | - Behnam Kamalidehghan
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | | | - Omid Aryani
- Department of Medical Genetics, Special Medical Center, Tehran, Iran
| | - Mahdi Tondar
- Department of Medical Genetics, Special Medical Center, Tehran, Iran
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, D.C., United States of America
| | - Fatemeh Ahmadipour
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Lip Yong Chung
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Massoud Houshmand
- Department of Medical Genetics, Special Medical Center, Tehran, Iran
- Department of Medical Genetics, National Institute for Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
- * E-mail:
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Wei AH, He X, Li W. Hypopigmentation in Hermansky-Pudlak syndrome. J Dermatol 2014; 40:325-9. [PMID: 23668540 DOI: 10.1111/1346-8138.12025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Accepted: 09/20/2012] [Indexed: 11/28/2022]
Abstract
Hermansky-Pudlak syndrome (HPS) is characterized by oculocutaneous albinism, bleeding tendency, and ceroid deposition which often leads to death in midlife. Currently, nine genes have been identified as causative for HPS in humans. Hypopigmentation is the prominent feature of HPS, attributable to the disrupted biogenesis of melanosome, a member of the lysosome-related organelle (LRO) family. Current understanding of the cargo transporting mechanisms into the melanosomes expands our knowledge of the pathogenesis of hypopigmentation in HPS patients.
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Affiliation(s)
- Ai-Hua Wei
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
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Montoliu L, Grønskov K, Wei AH, Martínez-García M, Fernández A, Arveiler B, Morice-Picard F, Riazuddin S, Suzuki T, Ahmed ZM, Rosenberg T, Li W. Increasing the complexity: new genes and new types of albinism. Pigment Cell Melanoma Res 2013; 27:11-8. [PMID: 24066960 DOI: 10.1111/pcmr.12167] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 09/08/2013] [Accepted: 09/17/2013] [Indexed: 12/24/2022]
Abstract
Albinism is a rare genetic condition globally characterized by a number of specific deficits in the visual system, resulting in poor vision, in association with a variable hypopigmentation phenotype. This lack or reduction in pigment might affect the eyes, skin, and hair (oculocutaneous albinism, OCA), or only the eyes (ocular albinism, OA). In addition, there are several syndromic forms of albinism (e.g. Hermansky-Pudlak and Chediak-Higashi syndromes, HPS and CHS, respectively) in which the described hypopigmented and visual phenotypes coexist with more severe pathological alterations. Recently, a locus has been mapped to the 4q24 human chromosomal region and thus represents an additional genetic cause of OCA, termed OCA5, while the gene is eventually identified. In addition, two new genes have been identified as causing OCA when mutated: SLC24A5 and C10orf11, and hence designated as OCA6 and OCA7, respectively. This consensus review, involving all laboratories that have reported these new genes, aims to update and agree upon the current gene nomenclature and types of albinism, while providing additional insights from the function of these new genes in pigment cells.
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Affiliation(s)
- Lluís Montoliu
- Department of Molecular and Cellular Biology, National Centre for Biotechnology (CNB-CSIC), Campus de Cantoblanco, Madrid, Spain; CIBERER, ISCIII, Madrid, Spain
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Mártinez-García M, Montoliu L. Albinism in Europe. J Dermatol 2013; 40:319-24. [DOI: 10.1111/1346-8138.12170] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 03/17/2013] [Indexed: 11/27/2022]
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Vidal-Ríos P, Fernández-Seara M, Cortés E, Hurtado L, Couce M. Albinismo oculocutáneo 1B asociado a una nueva mutación en el gen TYR. An Pediatr (Barc) 2013; 78:339-40. [DOI: 10.1016/j.anpedi.2012.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 07/22/2012] [Accepted: 09/05/2012] [Indexed: 10/27/2022] Open
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Simeonov DR, Wang X, Wang C, Sergeev Y, Dolinska M, Bower M, Fischer R, Winer D, Dubrovsky G, Balog JZ, Huizing M, Hart R, Zein WM, Gahl WA, Brooks BP, Adams DR. DNA variations in oculocutaneous albinism: an updated mutation list and current outstanding issues in molecular diagnostics. Hum Mutat 2013; 34:827-35. [PMID: 23504663 DOI: 10.1002/humu.22315] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 03/08/2013] [Indexed: 12/20/2022]
Abstract
Oculocutaneous albinism (OCA) is a rare genetic disorder of melanin synthesis that results in hypopigmented hair, skin, and eyes. There are four types of OCA caused by mutations in TYR (OCA-1), OCA2 (OCA-2), TYRP1 (OCA-3), or SLC45A2 (OCA-4). Here we report 22 novel mutations in the OCA genes; 14 from a cohort of 61 patients seen as part of the NIH OCA Natural History Study and eight from a prior study at the University of Minnesota. We also include a comprehensive list of almost 600 previously reported OCA mutations along with ethnicity information, carrier frequencies, and in silico pathogenicity predictions as a supplement. In addition to discussing the clinical and molecular features of OCA, we address the cases of apparent missing heritability. In our cohort, 26% of patients did not have two mutations in a single OCA gene. We demonstrate the utility of multiple detection methods to reveal mutations missed by Sanger sequencing. Finally, we review the TYR p.R402Q temperature-sensitive variant and confirm its association with cases of albinism with only one identifiable TYR mutation.
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Affiliation(s)
- Dimitre R Simeonov
- National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
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Wei AH, Zang DJ, Zhang Z, Liu XZ, He X, Yang L, Wang Y, Zhou ZY, Zhang MR, Dai LL, Yang XM, Li W. Exome sequencing identifies SLC24A5 as a candidate gene for nonsyndromic oculocutaneous albinism. J Invest Dermatol 2013; 133:1834-40. [PMID: 23364476 DOI: 10.1038/jid.2013.49] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Oculocutaneous albinism (OCA) is a heterogeneous and autosomal recessive disorder with hypopigmentation in the eye, hair, and skin color. Four genes, TYR, OCA2, TYRP1, and SLC45A2, have been identified as causative genes for nonsyndromic OCA1-4, respectively. The genetic identity of OCA5 locus on 4q24 is unknown. Additional unknown OCA genes may exist as at least 5% of OCA patients have not been characterized during mutational screening in several populations. We used exome sequencing with a family-based recessive mutation model to determine that SLC24A5 is a previously unreported candidate gene for nonsyndromic OCA, which we designate as OCA6. Two deleterious mutations in this patient, c.591G>A and c.1361insT, were identified. We found apparent increase of immature melanosomes and less mature melanosomes in the patient's skin melanocytes. However, no defects in the platelet dense granules were observed, excluding typical Hermansky-Pudlak syndrome (HPS), a well-known syndromic OCA. Moreover, the SLC24A5 protein was reduced in steady-state levels in mouse HPS mutants with deficiencies in BLOC-1 and BLOC-2. Our results suggest that SLC24A5 is a previously unreported nonsyndromic OCA candidate gene and that the SLC24A5 transporter is transported into mature melanosomes by HPS protein complexes.
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Affiliation(s)
- Ai-Hua Wei
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
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Wei AH, Li W. Hermansky-Pudlak syndrome: pigmentary and non-pigmentary defects and their pathogenesis. Pigment Cell Melanoma Res 2012; 26:176-92. [DOI: 10.1111/pcmr.12051] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 11/16/2012] [Indexed: 10/27/2022]
Affiliation(s)
| | - Wei Li
- State Key Laboratory of Molecular Developmental Biology; Institute of Genetics & Developmental Biology; Chinese Academy of Sciences; Beijing; China
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Yang Q, He X, Yang L, Zhou Z, Cullinane AR, Wei A, Zhang Z, Hao Z, Zhang A, He M, Feng Y, Gao X, Gahl WA, Huizing M, Li W. The BLOS1-interacting protein KXD1 is involved in the biogenesis of lysosome-related organelles. Traffic 2012; 13:1160-9. [PMID: 22554196 DOI: 10.1111/j.1600-0854.2012.01375.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 04/30/2012] [Accepted: 05/03/2012] [Indexed: 12/24/2022]
Abstract
Biogenesis of lysosome-related organelles (LROs) complex-1 (BLOC-1) is an eight-subunit complex involved in lysosomal trafficking. Interacting proteins of these subunits expand the understanding of its biological functions. With the implementation of the naïve Bayesian analysis, we found that a human uncharacterized 20 kDa coiled-coil KxDL protein, KXD1, is a BLOS1-interacting protein. In vitro binding assays confirmed the interaction between BLOS1 and KXD1. The mouse KXD1 homolog was widely expressed and absent in Kxd1 knockout (KO) mice. BLOS1 was apparently reduced in Kxd1-KO mice. Mild defects in the melanosomes of the retinal pigment epithelia and in the platelet dense granules of the Kxd1-KO mouse were observed, mimicking a mouse model of mild Hermansky-Pudlak syndrome that affects the biogenesis of LROs.
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Affiliation(s)
- Qing Yang
- State Key Laboratory of Molecular and Developmental Biology, Institute of Genetics & Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
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REINDERS ANKE, WARD JOHNM. Investigating polymorphisms in membrane-associated transporter protein SLC45A2, using sucrose transporters as a model. Mol Med Rep 2012; 12:1393-8. [DOI: 10.3892/mmr.2015.3462] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 02/05/2015] [Indexed: 11/06/2022] Open
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Ko JM, Yang JA, Jeong SY, Kim HJ. Mutation spectrum of the TYR and SLC45A2 genes in patients with oculocutaneous albinism. Mol Med Rep 2012; 5:943-8. [PMID: 22294196 PMCID: PMC3493039 DOI: 10.3892/mmr.2012.764] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 01/11/2012] [Indexed: 12/24/2022] Open
Abstract
Oculocutaneous albinism (OCA) is a group of inherited disorders characterized by defective melanin biosynthesis. OCA1, the most common and severe form, is caused by mutations in the tyrosinase (TYR) gene. OCA4, caused by mutations in the SLC45A2 gene, has frequently been reported in the Japanese population. To determine the mutational spectrum in Korean OCA patients, 12 patients were recruited. The samples were first screened for TYR mutations, and negative samples were screened for SLC45A2 mutations. OCA1 was confirmed in 8 of 12 (66.7%) patients, and OCA4 was diagnosed in 1 (8.3%) patient. In the OCA1 patients, a total of 6 distinct TYR mutations were found in 15 of 16 (93.8%) alleles, all of which had been previously reported. Out of the 6 alleles, c.929insC was the most frequently detected (31.3%), and was mainly associated with OCA1A phenotypes. Other TYR mutations identified included c.1037-7T>A/c.1037-10delTT, p.D383N, p.R77Q and p.R299H. These largely overlapped with mutations found in Japanese and Chinese patients. The SLC45A2 gene analysis identified 1 novel mutation, p.D93N, in 1 patient. This study has provided information on the mutation spectrum in Korean OCA patients, and allows us to estimate the relative frequencies of OCA1 and OCA4 in Korea.
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Affiliation(s)
- Jung Min Ko
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul 110-769, Republic of Korea.
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Yamada M, Sakai K, Hayashi M, Hozumi Y, Abe Y, Kawaguchi M, Ihn H, Suzuki T. Oculocutaneous albinism type 3: A Japanese girl with novel mutations in TYRP1 gene. J Dermatol Sci 2011; 64:217-22. [DOI: 10.1016/j.jdermsci.2011.09.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2011] [Revised: 09/07/2011] [Accepted: 09/09/2011] [Indexed: 12/11/2022]
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