1
|
Gao S, Zhang Q, Ding Y, Wang L, Li Z, Hu F, Yao RE, Yu T, Chang G, Wang X. Molecular and phenotypic characteristics of Bardet-Biedl syndrome in Chinese patients. Orphanet J Rare Dis 2024; 19:149. [PMID: 38584252 PMCID: PMC11000329 DOI: 10.1186/s13023-024-03150-9] [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: 09/08/2023] [Accepted: 03/27/2024] [Indexed: 04/09/2024] Open
Abstract
BACKGROUND Bardet-Biedl syndrome (BBS) is a type of non-motile ciliopathy. To date, 26 genes have been reported to be associated with BBS. However, BBS is genetically heterogeneous, with significant clinical overlap with other ciliopathies, which complicates diagnosis. Disability and mortality rates are high in BBS patients; therefore, it is urgent to improve our understanding of BBS. Thus, our study aimed to describe the genotypic and phenotypic spectra of BBS in China and to elucidate genotype-phenotype correlations. METHODS Twenty Chinese patients diagnosed with BBS were enrolled in this study. We compared the phenotypes of Chinese BBS patients in this study with those from other countries to analyze the phenotypic differences across patients worldwide. In addition, genotype-phenotype correlations were described for our cohort. We also summarized all previously reported cases of BBS in Chinese patients (71 patients) and identified common and specific genetic variants in the Chinese population. RESULTS Twenty-eight variants, of which 10 are novel, in 5 different BBS-associated genes were identified in 20 Chinese BBS patients. By comparing the phenotypes of BBSome-coding genes (BBS2,7,9) with those of chaperonin-coding genes (BBS10,12), we found that patients with mutations in BBS10 and 12 had an earlier age of onset (1.10 Vs. 2.20, p < 0.01) and diagnosis (4.64 Vs. 13.17, p < 0.01), whereas patients with mutations in BBS2, 7, and 9 had a higher body mass index (28.35 Vs. 24.21, p < 0.05) and more vision problems (p < 0.05). Furthermore, in 91 Chinese BBS patients, mutations were predominant in BBS2 (28.89%) and BBS7 (15.56%), and the most frequent variants were in BBS2: c.534 + 1G > T (10/182 alleles) and BBS7: c.1002delT (7/182 alleles), marking a difference from the genotypic spectra of BBS reported abroad. CONCLUSIONS We recruited 20 Chinese patients with BBS for genetic and phenotypic analyses, and identified common clinical manifestations, pathogenic genes, and variants. We also described the phenotypic differences across patients worldwide and among different BBS-associated genes. This study involved the largest cohort of Chinese patients with BBS, and provides new insights into the distinctive clinical features of specific pathogenic variants.
Collapse
Affiliation(s)
- Shiyang Gao
- Department of Endocrinology, Metabolism and Genetics, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Qianwen Zhang
- Department of Endocrinology, Metabolism and Genetics, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Yu Ding
- Department of Endocrinology, Metabolism and Genetics, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Libo Wang
- Department of Endocrinology, Metabolism and Genetics, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Zhiying Li
- Department of Endocrinology, Metabolism and Genetics, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Feihan Hu
- Department of Endocrinology, Metabolism and Genetics, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Ru-En Yao
- Department of Genetic Molecular Diagnostic Laboratory, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Tingting Yu
- Department of Genetic Molecular Diagnostic Laboratory, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China
| | - Guoying Chang
- Department of Endocrinology, Metabolism and Genetics, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
| | - Xiumin Wang
- Department of Endocrinology, Metabolism and Genetics, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200127, China.
| |
Collapse
|
2
|
Xin-Yi Z, Yang-Li D, Ling-Hui Z. Review of the phenotypes and genotypes of Bardet-Biedl syndrome from China. Front Genet 2023; 14:1247557. [PMID: 38034494 PMCID: PMC10684923 DOI: 10.3389/fgene.2023.1247557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 10/27/2023] [Indexed: 12/02/2023] Open
Abstract
Objective: To analyze the phenotypes, genotypes, and the relationship of phenotypes and genotypes for Chinese patients with Bardet-Biedl syndrome (BBS). Methods: The Chinese Wanfang and Weipu data, and PubMed were searched up to December 2022. Patients with detailed clinical feature data were involved in the analysis. Results: A total of 153 Chinese patients, including 87 males, 53 females, and 12 unknown, were enrolled. Their ages ranged from 1.2 to 44 years old with a mean of 16.70 ± 9.90 years old. Among these patients, 80 (52.29%) were reported by ophthalmologists, and only 24 (15.68%) reported by pediatricians. Most patients (132/137, 96.35%) had visual problems; 131/153 (85.62%) had polydactyly; 124/132 (93.93%) were overweight or obese; 63/114 (55.26%) had renal abnormalities; kidney dysfunction was found in 33 (21.57%); 83/104 (79.81%) had hypogonadism and/or genital hypoplasia; and 111/136 (81.62%) had mental retardation. In this series, genetic analysis was performed in 90 (58.82%) patients, including 22 BBS7 (24.71%), 20 BBS2 (22.73%), and 10 BBS10 (11.24%) patients. Moreover, 11 fetuses were diagnosed prenatally in the last 4 years except for one patient in 2004 year. It was noted that BBS7 had higher penetrance. BBS2 had higher hearing impairment and lower renal abnormality penetrance. BBS10 also had lower renal abnormality penetrance as well. Conclusion: Misdiagnosis or miss diagnosis of BBS may be common in China. In patients with polydactyly, visual impairment, obesity, renal abnormalities, hypogonadism, and mental retardation, or in fetuses with polydactyly and/or renal abnormalities, BBS should be considered in the differential diagnosis. Other deformities should be evaluated carefully and genetic analysis should be performed as early as possible.
Collapse
Affiliation(s)
- Zou Xin-Yi
- Department of Clinical Medicine, Medical School of Hangzhou City University, Hangzhou, China
| | - Dai Yang-Li
- Department of Endocrinology, The Children’s Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Zeng Ling-Hui
- Department of Clinical Medicine, Medical School of Hangzhou City University, Hangzhou, China
| |
Collapse
|
3
|
Meyer JR, Krentz AD, Berg RL, Richardson JG, Pomeroy J, Hebbring SJ, Haws RM. Kidney Failure in Bardet-Biedl Syndrome. Clin Genet 2022; 101:429-441. [PMID: 35112343 PMCID: PMC9311438 DOI: 10.1111/cge.14119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 01/29/2022] [Accepted: 01/30/2022] [Indexed: 11/29/2022]
Abstract
The aim of this study was to explore kidney failure (KF) in Bardet–Biedl syndrome (BBS), focusing on high‐risk gene variants, demographics, and morbidity. We employed the Clinical Registry Investigating BBS (CRIBBS) to identify 44 (7.2%) individuals with KF out of 607 subjects. Molecularly confirmed BBS was identified in 37 KF subjects and 364 CRIBBS registrants. KF was concomitant with recessive causal variants in 12 genes, with BBS10 the most predominant causal gene (26.6%), while disease penetrance was highest in SDCCAG8 (100%). Two truncating variants were present in 67.6% of KF cases. KF incidence was increased in genes not belonging to the BBSome or chaperonin‐like genes (p < 0.001), including TTC21B, a new candidate BBS gene. Median age of KF was 12.5 years, with the vast majority of KF occurring by 30 years (86.3%). Females were disproportionately affected (77.3%). Diverse uropathies were identified, but were not more common in the KF group (p = 0.672). Kidney failure was evident in 11 of 15 (73.3%) deaths outside infancy. We conclude that KF poses a significant risk for premature morbidity in BBS. Risk factors for KF include female sex, truncating variants, and genes other than BBSome/chaperonin‐like genes highlighting the value of comprehensive genetic investigation.
Collapse
Affiliation(s)
- Jennifer R Meyer
- University of Wisconsin, School of Medicine and Public Health, Madison, WI, USA
| | | | - Richard L Berg
- Marshfield Clinic Research Institute, Marshfield, Wisconsin, USA
| | | | - Jeremy Pomeroy
- Marshfield Clinic Research Institute, Marshfield, Wisconsin, USA
| | - Scott J Hebbring
- Marshfield Clinic Research Institute, Marshfield, Wisconsin, USA
| | - Robert M Haws
- Marshfield Clinic Research Institute, Marshfield, Wisconsin, USA.,Marshfield Clinic Health System, Marshfield, Wisconsin, USA
| |
Collapse
|
4
|
Aleman TS, O'Neil EC, O'Connor K, Jiang YY, Aleman IA, Bennett J, Morgan JIW, Toussaint BW. Bardet-Biedl syndrome-7 ( BBS7) shows treatment potential and a cone-rod dystrophy phenotype that recapitulates the non-human primate model. Ophthalmic Genet 2021; 42:252-265. [PMID: 33729075 DOI: 10.1080/13816810.2021.1888132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Purpose: To provide a detailed ophthalmic phenotype of two male patients with Bardet-Biedl Syndrome (BBS) due to mutations in the BBS7 geneMethods: Two brothers ages 26 (Patient 1, P1) and 23 (P2) underwent comprehensive ophthalmic evaluations over three years. Visual function was assessed with full-field electroretinograms (ffERGs), kinetic and chromatic perimetry, multimodal imaging with spectral domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF) with short- (SW) and near-infrared (NIR) excitation lights and adaptive optics scanning light ophthalmoscopy (AOSLO).Results: Both siblings had a history of obesity and postaxial polydactyly; P2 had diagnoses of type 1 Diabetes Mellitus, Addison's disease, high-functioning autism-spectrum disorder and -12D myopia. Visual acuities were better than 20/30. Kinetic fields were moderately constricted. Cone-mediated ffERGs were undetectable, rod ERGs were ~80% of normal mean. Static perimetry showed severe central cone and rod dysfunction. Foveal to parafoveal hypoautofluorescence, most obvious on NIR-FAF, co-localized with outer segment shortening/loss and outer nuclear layer thinning by SD-OCT, and with reduced photoreceptors densities by AOSLO. A structural-functional dissociation was confirmed for cone- and rod-mediated parameters. Worsening of the above abnormalities was documented by SD-OCT and FAF in P2 at 3 years. Gene screening identified compound heterozygous mutations in BBS7 (p.Val266Glu: c.797 T > A of maternal origin; c.1781_1783delCAT, paternal) in both patients.Conclusions: BBS7-associated retinal degeneration may present as a progressive cone-rod dystrophy pattern, reminiscent of both the murine and non-human primate models of the disease. Predominantly central retinal abnormalities in both cone and rod photoreceptors showed a structural-functional dissociation, an ideal scenario for gene augmentation treatments.
Collapse
Affiliation(s)
- Tomas S Aleman
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Division of Ophthalmology of the Children's Hospital of Philadelphia, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Erin C O'Neil
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Division of Ophthalmology of the Children's Hospital of Philadelphia, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Keli O'Connor
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Yu You Jiang
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Isabella A Aleman
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jean Bennett
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jessica I W Morgan
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Brian W Toussaint
- Christiana Care Health System, Wilmington, Delaware, USA.,Department of Ophthalmology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA
| |
Collapse
|
5
|
Meng X, Long Y, Ren J, Wang G, Yin X, Li S. Ocular Characteristics of Patients With Bardet-Biedl Syndrome Caused by Pathogenic BBS Gene Variation in a Chinese Cohort. Front Cell Dev Biol 2021; 9:635216. [PMID: 33777945 PMCID: PMC7991091 DOI: 10.3389/fcell.2021.635216] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/08/2021] [Indexed: 12/29/2022] Open
Abstract
Bardet–Biedl syndrome (BBS; OMIM 209900) is a rare genetic disease causing damage to multiple organs and affecting patients’ quality of life in late adolescence or early adulthood. In this study, the ocular characteristics including morphology and function, were analyzed in 12 BBS patients from 10 Chinese families by molecular diagnostics. A total of five known and twelve novel variants in four BBS genes (BBS2, 58.33%; BBS4, 8.33%; BBS7, 16.67%; and BBS9, 16.67%) were identified in 10 Chinese families with BBS. All patients had typical phenotypes of retinitis pigmentosa with unrecordable or severely damaged cone and rod responses on full-field flash electroretinography (ffERG). Most of the patients showed unremarkable reactions in pattern visual evoked potential (PVEP) and multifocal electroretinography (mfERG), while their flash visual evoked potentials (FVEP) indicated display residual visual function. Changes in the fundus morphology, including color fundus photography and autofluorescence (AF) imaging, were heterogeneous and not consistent with the patients’ functional tests. Overall, our study expands the variation spectrum of the BBS gene, showing that the ocular characteristics of BBS patients are clinically highly heterogeneous, and demonstrates the usefulness of a combination of the ffERG and FVEP assessments of visual function in the advanced stage of retinopathy in BBS.
Collapse
Affiliation(s)
- Xiaohong Meng
- Department of Ophthalmology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Yanling Long
- Department of Ophthalmology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Jiayun Ren
- Department of Ophthalmology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Gang Wang
- Department of Ophthalmology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Xin Yin
- Department of Ophthalmology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Shiying Li
- Department of Ophthalmology, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, China.,Key Laboratory of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| |
Collapse
|
6
|
Gumus E, Tuncez E, Oz O, Saka Guvenc M. Clinical and exome sequencing findings in seven children with Bardet-Biedl syndrome from Turkey. Ann Hum Genet 2020; 85:27-36. [PMID: 32686083 DOI: 10.1111/ahg.12401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 07/02/2020] [Accepted: 07/02/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Bardet-Biedl syndrome (BBS) is a very-rare autosomal recessive genetic disorder with severe multisystem manifestations. Genetic testing plays an important role in the early diagnosis of the disease. In this study, while trying to elucidate the genetic etiology of seven individuals with clinical BBS diagnosis from six different families, we also aimed to examine the distribution of BBS variations in this region of Turkey. METHODS AND MATERIALS Exome sequencing analysis is performed for clinically diagnosed patients with BBS in the present study followed by parental segregation. The unreported and previously described clinical features are presented. RESULTS Homozygous variants, four of which are unreported, in BBS-related genes (BBS5 [c.682-2A > G], MKKS [c.775del], BBS7 [c.849+1G > T], BBS9 [c.965G > A], BBS10 [c.145C > T], LZTFL1[c.384G > A]) are detected for all the seven individuals included in the study. The most common clinical finding is polydactyly followed by renal anomalies. The clinical features not previously described are correlated to the unreported variant. CONCLUSIONS In this study, exome sequencing findings are discussed and four previously unreported disease-associated variants are described including the fifth BBS-implicated LZTFL1 change and possible genotype-phenotype correlation is described.
Collapse
Affiliation(s)
- Evren Gumus
- Department of Medical Genetics, Faculty of Medicine, University of Harran, Sanliurfa, Turkey.,Department of Medical Genetics, Faculty of Medicine, University of Mugla Sitki Kocman, Mugla, Turkey
| | - Ebru Tuncez
- Clinic of Medical Genetics, Sanliurfa Training and Research Hospital, Sanliurfa, Turkey
| | - Ozlem Oz
- Department of Medical Genetics, Faculty of Medicine, University of Harran, Sanliurfa, Turkey
| | - Merve Saka Guvenc
- Genetic Diagnosis Center, Tepecik Training and Research Hospital, University of Health Sciences, Izmir, Turkey
| |
Collapse
|
7
|
Tao T, Wang L, Chong W, Yang L, Li G. Characteristics of genotype and phenotype in Chinese patients with Bardet-Biedl syndrome. Int Ophthalmol 2020; 40:2325-2343. [PMID: 32448990 DOI: 10.1007/s10792-020-01415-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 05/02/2020] [Indexed: 12/31/2022]
Abstract
PURPOSE To investigate complex and different phenotypes in seven Chinese patients diagnosed with Bardet-Biedl syndrome (BBS) and carrying pathogenic mutations. METHODS Seven unrelated BBS patients were enrolled. Their medical and ophthalmic histories were reviewed, and comprehensive clinical examinations, such as fundus photography, optical coherence tomography, and medical imaging, were performed. A specific hereditary eye disease enrichment panel based on exome-capture technology was used to collect and amplify the protein-coding regions of 441 targeted hereditary eye disease genes, followed by high-throughput sequencing using the Illumina HiSeq platform. RESULTS All patients exhibited the primary clinical phenotype of BBS. Seven BBS mutations were found in five patients (BBS7 in two patients, BBS10 in two patients, BBS12 in one patient), for a detection rate of 71% (5/7). The ratio of novel to known BBS mutations was 5:2. CONCLUSIONS This study showed the phenotypic and genotypic spectrum of BBS patients from China, and the findings underscore the importance of obtaining comprehensive clinical observations and molecular analyses for ciliopathies.
Collapse
Affiliation(s)
- Tianchang Tao
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Lei Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Weihua Chong
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Liping Yang
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Restoration of Damaged Ocular Nerve Beijing, Beijing, People's Republic of China
| | - Genlin Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China.
| |
Collapse
|