Clinical phenotype and genotypic analysis of a four-generation Chinese pedigree affected with Stickler syndrome and a literature review
10.3760/cma.j.cn511374-20250418-00235
- VernacularTitle:Stickler综合征Ⅰ型1个四代家系的临床表型及基因型研究
- Author:
Wenjun HE
1
;
Fang TANG
;
Fan JIANG
;
Ziman CHEN
;
Yan LU
;
Yutong NI
;
Jianying ZHOU
;
Dongzhi LI
Author Information
1. 广州中医药大学第二附属医院，广东省中医院，广州 510370
- Publication Type:Journal Article
- Keywords:
Stickler syndrome type I;
COL2A1 gene;
Retinal detachment;
Pierre-Robin sequence
- From:
Chinese Journal of Medical Genetics
2025;42(6):684-690
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To carry out genetic testing and clinical phenotypic characterization on a four-generation Chinese pedigree affected with Stickler syndrome type I and explore its genotype-phenotype correlation.Methods:A child presented at the Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine in February 2023 for micrognathia, glossoptosis and cleft palate and his family members were selected as the study subjects. Clinical data were collected from the affected members, and peripheral blood samples were obtained from 17 participants (4 patients and 13 asymptomatic individuals). Whole exome sequencing (WES) was carried out. Candidate variant was verified by Sanger sequencing. Genotype-phenotype correlations were analyzed by integrating the sequencing data with evidence from existing literature. This study has bee granted by the Ethics Committee of Guangdong Provincial Hospital of Traditional Chinese Medicine and Guangzhou Women and Children′s Medical Center (Ethics No.: 2022-406B00).Results:The four-generation pedigree has comprised 19 members. In addition to the proband, 5 affected individuals had manifested high myopia, congenital cataracts, and progressive vision loss. Two deceased members reportedly exhibited similar ocular manifestations. Among the four living patients, two had developed retinal detachment, while two others presented with chronic joint pain onset between 35 ~ 40 years of age. One patient required hip replacement surgery at age 42 secondary to femoral head necrosis. The proband, the youngest affected member, exhibited characteristic phenotypes including congenital micrognathia and cleft palate, consistent with Pierre-Robin syndrome. Genetic analysis revealed a heterozygous nonsense mutation in COL2A1 (NM_001844.5: c. 2668C>T; p. Gln890Ter) segregating with the disease in all four symptomatic patients. This variant was absent in asymptomatic family members and unaffected controls. While the mutation is listed in ClinVar, no clinical case reports has associated it with this phenotypic spectrum. It was not observed in population databases (gnomAD v4.1.0, 1000 Genomes Project, or ExAC), supporting its potential pathogenicity. Conclusion:This study has diagnosed a four-generation Chinese pedigree with Stickler syndrome type I attributed to the pathogenic COL2A1 variant c. 2668C>T (p.Gln890Ter), which is a rare nonsense mutation associated with ocular predominance and variable skeletal involvement. Notably, this family exhibited marked clinical heterogeneity despite sharing the identical genotype, which highlighted challenges in phenotype-genotype correlation. The autosomal dominant transmission pattern observed in this pedigree has provided critical insights into COL2A1-related collagenopathies and underscored the necessity of ultrasonographic monitoring for ocular anomalies in prenatal diagnostics. Above findings have advanced our understanding of pleiotropic effects in type Ⅱ collagen disorders and lay the foundation for precision-based genetic counseling, enabling targeted cascade screening and implementation of tertiary prevention strategies against congenital disabilities in high-risk families.
