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Karim S, Saharti S, Alganmi N, Mirza Z, Alfares A, Turkistany S, Al-Attas M, Noureldin H, Al Sakkaf K, Abusamra H, Al-Qahtani M, Abuzenadah A. Two Novel Homozygous HPS6 Mutations (Double Mutant) Identified by Whole-Exome Sequencing in a Saudi Consanguineous Family Suspected for Oculocutaneous Albinism. Life (Basel) 2021; 12:life12010014. [PMID: 35054407 PMCID: PMC8779141 DOI: 10.3390/life12010014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 12/11/2021] [Accepted: 12/13/2021] [Indexed: 11/28/2022] Open
Abstract
Background: Oculocutaneous albinism (OCA) is an autosomal recessive disorder of low or missing pigmentation in the eyes, hair, and skin. Multiple types of OCA, including Hermansky-Pudlak syndrome 6 (HPS6), are distinguished by their genetic cause and pigmentation pattern. HPS6 is characterized by OCA, nose bleeding due to platelet dysfunction, and lysosome storage defect. To date, 25 disease-associated mutations have been reported in the HPS6 gene. Methods: DNA was extracted from proband, and whole-exome sequencing (WES) was performed using the Illumina NovaSeq platform. Bioinformatic analysis was done with a custom-designed filter pipeline to detect the causative variant. We did Sanger sequencing to confirm the candidate variant and segregation analysis, and protein-based structural analysis to evaluate the functional impact of variants. Result: Proband-based WES identified two novel homozygous mutations in HPS6 (double mutation, c.1136C>A and c.1789delG) in an OCA suspect. Sanger sequencing confirmed the WES results. Although no platelet and/or lysosome storage defect was detected in the patient or family, an oculocutaneous albinism diagnosis was established based on the HPS6 mutations. Structural analysis revealed the transformation of abnormalities at protein level for both nonsense and frameshift mutations in HPS6. Conclusion: To the best of our knowledge, the double mutation in HPS6 (p.Ser379Ter and p.Ala597GlnfsTer16) represents novel pathogenic variants, not described previously, which we report for the first time in the Saudi family. In silico analyses showed a significant impact on protein structure. WES should be used to identify HPS6 and/or other disease-associated genetic variants in Saudi Arabia, particularly in consanguineous families.
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Affiliation(s)
- Sajjad Karim
- Center of Excellence in Genomic Medicine Research, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-Q.); (A.A.)
- Department of Medical Lab Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
- Correspondence: ; Tel.: +966-557581741
| | - Samah Saharti
- Department of Pathology, Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
| | - Nofe Alganmi
- Computer Science Department, Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
| | - Zeenat Mirza
- Department of Medical Lab Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
- King Fahd Medical Research Center, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Ahmed Alfares
- Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Riyadh 11426, Saudi Arabia;
| | - Shereen Turkistany
- Center of Innovation in Personalized Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
| | - Manal Al-Attas
- Roya Specialized Medical Laboratories, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-A.); (H.N.); (K.A.S.); (H.A.)
| | - Hend Noureldin
- Roya Specialized Medical Laboratories, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-A.); (H.N.); (K.A.S.); (H.A.)
| | - Khadega Al Sakkaf
- Roya Specialized Medical Laboratories, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-A.); (H.N.); (K.A.S.); (H.A.)
| | - Heba Abusamra
- Roya Specialized Medical Laboratories, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-A.); (H.N.); (K.A.S.); (H.A.)
| | - Mohammed Al-Qahtani
- Center of Excellence in Genomic Medicine Research, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-Q.); (A.A.)
| | - Adel Abuzenadah
- Center of Excellence in Genomic Medicine Research, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-Q.); (A.A.)
- Department of Medical Lab Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
- King Fahd Medical Research Center, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Roya Specialized Medical Laboratories, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (M.A.-A.); (H.N.); (K.A.S.); (H.A.)
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Wang Y. Association of pigmentation related-genes polymorphisms and geographic environmental variables in the Chinese population. Hereditas 2021; 158:24. [PMID: 34238381 PMCID: PMC8268332 DOI: 10.1186/s41065-021-00189-7] [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: 11/30/2020] [Accepted: 06/09/2021] [Indexed: 11/10/2022] Open
Abstract
Background Human skin color is highly heritable and one of the most variable phenotypic traits. However, the genetic causes and environmental selective pressures underlying this phenotypic variation have remained largely unknown. To investigate whether the pigmentation related-genes polymorphisms are associated with the geographic environmental variables. We selected randomly 795 healthy individuals from eight ethnic groups in nine provinces in China. Six single nucleotide polymorphisms (SNPs) of SLC45A2 and TYR were genotyped using Agena MassARRAY. The Chi-square test and Spearman correlation analysis were used to compare the frequency distribution of genotypes among different ethnic groups and evaluate the relationship between SNP genetic diversity and environmental variables, respectively. Results The results indicated that rs28777 and rs183671 (SLC45A2) and rs1042602 (TYR) genotype frequency distributions were significantly different between the Xinjiang-Uighur and other ethnic groups (P < 0.05). Spearman correlation analysis found that rs28777-A (r = − 0.090, P = 0.011), rs183671-G (r = − 0.105, P = 0.003), rs1042602-A (r = − 0.108, P = 0.002), rs1126809-A (r = − 0.151, P < 0.001) allele frequencies were negatively correlated with the longitude; rs183671-G (r = 0.151), rs1042602-A (r = 0.157) and rs1126809-A (r = 0.138) allele frequencies were positively associated with the latitude (P < 0.001); rs183671-G (r = 0.116, P = 0.001), rs1042602-A (r = 0.105, P = 0.003) and rs1126809-A (r = 0.070, P = 0.048) allele frequencies were positively correlated with the sunshine hours; rs183671-G (r = − 0.076, P = 0.033), rs1042602-A (r = − 0.079, P = 0.027) and rs1126809-A (r = − 0.076, P = 0.031) were negatively correlated with the annual average temperature. Conclusions Our results confirmed the idea that environmental factors have been an important selective pressure upon pigmentation related gene polymorphisms. Supplementary Information The online version contains supplementary material available at 10.1186/s41065-021-00189-7.
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Affiliation(s)
- Yuxin Wang
- Queen Mary School, Nanchang University, 461 Bayi Road, Nanchang, 330006, Jiangxi, China.
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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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Rothammer S, Kunz E, Seichter D, Krebs S, Wassertheurer M, Fries R, Brem G, Medugorac I. Detection of two non-synonymous SNPs in SLC45A2 on BTA20 as candidate causal mutations for oculocutaneous albinism in Braunvieh cattle. Genet Sel Evol 2017; 49:73. [PMID: 28982372 PMCID: PMC5628493 DOI: 10.1186/s12711-017-0349-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 09/27/2017] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Cases of albinism have been reported in several species including cattle. So far, research has identified many genes that are involved in this eye-catching phenotype. Thus, when two paternal Braunvieh half-sibs with oculocutaneous albinism were detected on a private farm, we were interested in knowing whether their phenotype was caused by an already known gene/mutation. RESULTS Analysis of genotyping data (50K) of the two albino individuals, their mothers and five other relatives identified a 47.61-Mb candidate haplotype on Bos taurus chromosome BTA20. Subsequent comparisons of the sequence of this haplotype with sequence data from four Braunvieh sires and the Aurochs genome identified two possible candidate causal mutations at positions 39,829,806 bp (G/A; R45Q) and 39,864,148 bp (C/T; T444I) that were absent in 1682 animals from various bovine breeds included in the 1000 bull genomes project. Both polymorphisms represent coding variants in the SLC45A2 gene, for which the human equivalent harbors numerous variants associated with oculocutaneous albinism type 4. We demonstrate an association of R45Q and T444I with the albino phenotype by targeted genotyping. CONCLUSIONS Although the candidate gene SLC45A2 is known to be involved in albinism in different species, to date in cattle only mutations in the TYR and MITF genes were reported to be associated with albinism or albinism-like phenotypes. Thus, our study extends the list of genes that are associated with bovine albinism. However, further research and more samples from related animals are needed to elucidate if only one of these two single nucleotide polymorphisms or the combination of both is the actual causal variant.
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Affiliation(s)
- Sophie Rothammer
- Chair of Animal Genetics and Husbandry, LMU Munich, Veterinaerstr. 13, 80539, Munich, Germany
| | - Elisabeth Kunz
- Chair of Animal Genetics and Husbandry, LMU Munich, Veterinaerstr. 13, 80539, Munich, Germany
| | - Doris Seichter
- Tierzuchtforschung e.V. München, Senator-Gerauer-Strasse 23a, 85586, Poing, Germany
| | - Stefan Krebs
- Laboratory for Functional Genome Analysis, Gene Center, LMU Munich, Feodor-Lynen-Strasse 25, 81377, Munich, Germany
| | - Martina Wassertheurer
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria
| | - Ruedi Fries
- Chair of Animal Breeding, TU Munich, Liesel-Beckmann-Strasse (Hochfeldweg) 1, 85354, Freising-Weihenstephan, Germany
| | - Gottfried Brem
- Institute of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria
| | - Ivica Medugorac
- Chair of Animal Genetics and Husbandry, LMU Munich, Veterinaerstr. 13, 80539, Munich, Germany.
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Clinical evaluation and molecular screening of a large consecutive series of albino patients. J Hum Genet 2016; 62:277-290. [PMID: 27734839 DOI: 10.1038/jhg.2016.123] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 09/08/2016] [Accepted: 09/10/2016] [Indexed: 12/26/2022]
Abstract
Oculocutaneous albinism (OCA) is characterized by hypopigmentation of the skin, hair and eye, and by ophthalmologic abnormalities caused by a deficiency in melanin biosynthesis. In this study we recruited 321 albino patients and screened them for the genes known to cause oculocutaneous albinism (OCA1-4 and OCA6) and ocular albinism (OA1). Our purpose was to detect mutations and genetic frequencies of the main causative genes, offering to albino patients an exhaustive diagnostic assessment within a multidisciplinary approach including ophthalmological, dermatological, audiological and genetic evaluations. We report 70 novel mutations and the frequencies of the major causative OCA genes that are as follows: TYR (44%), OCA2 (17%), TYRP1 (1%), SLC45A2 (7%) and SLC24A5 (<0.5%). An additional 5% of patients had GPR143 mutations. In 19% of cases, a second reliable mutation was not detected, whereas 7% of our patients remain still molecularly undiagnosed. This comprehensive study of a consecutive series of OCA/OA1 patients allowed us to perform a clinical evaluation of the different OCA forms.
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Veniani E, Mauri L, Manfredini E, Gesu GP, Patrosso MC, Zelante L, D'Agruma L, Del Longo A, Mazza M, Piozzi E, Penco S, Primignani P. Detection of the first OCA6 Italian patient in a large cohort of albino subjects. J Dermatol Sci 2015; 81:208-9. [PMID: 26686029 DOI: 10.1016/j.jdermsci.2015.11.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 11/16/2015] [Accepted: 11/26/2015] [Indexed: 11/18/2022]
Affiliation(s)
- Emanuela Veniani
- Medical Genetics Unit-Department of Laboratory Medicine, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Lucia Mauri
- Medical Genetics Unit-Department of Laboratory Medicine, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Emanuela Manfredini
- Medical Genetics Unit-Department of Laboratory Medicine, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Giovanni P Gesu
- Medical Genetics Unit-Department of Laboratory Medicine, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Maria Cristina Patrosso
- Medical Genetics Unit-Department of Laboratory Medicine, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Leopoldo Zelante
- UOC Medical Genetics-"IRCCS Casa Sollievo della Sofferenza", San Giovanni Rotondo, Italy
| | - Leonardo D'Agruma
- UOC Medical Genetics-"IRCCS Casa Sollievo della Sofferenza", San Giovanni Rotondo, Italy
| | | | - Marco Mazza
- Pediatric Ophthalmolgy Department, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Elena Piozzi
- Pediatric Ophthalmolgy Department, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Silvana Penco
- Medical Genetics Unit-Department of Laboratory Medicine, Niguarda Ca' Granda Hospital, Milan, Italy
| | - Paola Primignani
- Medical Genetics Unit-Department of Laboratory Medicine, Niguarda Ca' Granda Hospital, Milan, Italy.
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McCafferty BK, Wilk MA, McAllister JT, Stepien KE, Dubis AM, Brilliant MH, Anderson JL, Carroll J, Summers CG. Clinical Insights Into Foveal Morphology in Albinism. J Pediatr Ophthalmol Strabismus 2015; 52:167-72. [PMID: 26053207 PMCID: PMC4948980 DOI: 10.3928/01913913-20150427-06] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Accepted: 01/13/2015] [Indexed: 11/20/2022]
Abstract
PURPOSE A hallmark of albinism is foveal hypoplasia. However, literature suggests variable foveal development. This study evaluates the association between ocular phenotype and foveal morphology to demonstrate the broad structural and functional spectrum. METHODS Best-corrected visual acuity (BCVA), nystagmus, angle kappa, stereoacuity, iris transillumination, macular melanin presence, foveal avascular zone, and annular reflex were recorded in 14 patients with albinism. Spectral-domain optical coherence tomography provided macular images. RESULTS The clinical phenotype was broad, with BCVA varying from 20/20 to 20/100. Better BCVA was associated with a preserved foveal avascular zone, annular macular reflex, stereoacuity, and macular melanin. Imaging demonstrated a continuum of foveal development correlating with BCVA. Individuals with a rudimentary pit had normal inner and outer segment lengthening and better BCVA. CONCLUSIONS The spectrum of ocular structure and visual function in albinism is broad, suggesting a possible diagnosis of albinism in a patient with an even more normal clinical presentation.
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MESH Headings
- Adolescent
- Adult
- Aged, 80 and over
- Albinism, Ocular/diagnosis
- Albinism, Ocular/genetics
- Albinism, Ocular/physiopathology
- Albinism, Oculocutaneous/diagnosis
- Albinism, Oculocutaneous/genetics
- Albinism, Oculocutaneous/physiopathology
- Child
- DNA Mutational Analysis
- Depth Perception/physiology
- Evoked Potentials, Visual
- Eye Abnormalities/diagnosis
- Eye Abnormalities/genetics
- Eye Abnormalities/physiopathology
- Eye Proteins/genetics
- Female
- Fovea Centralis/abnormalities
- Fovea Centralis/pathology
- Humans
- Male
- Membrane Proteins/genetics
- Nystagmus, Pathologic/diagnosis
- Phenotype
- Polymerase Chain Reaction
- Prospective Studies
- Tomography, Optical Coherence
- Visual Acuity/physiology
- Young Adult
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