Molecular diagnosis, clinical evaluation and phenotypic spectrum of Townes-Brocks syndrome : insights from a large Chinese hearing loss cohort

© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ..

BACKGROUND: Townes-Brocks syndrome (TBS) is a rare genetic disorder characterised by multiple malformations. Due to its phenotypic heterogeneity and rarity, diagnosis and recognition of TBS can be challenging and there has been a lack of investigation of patients with atypical TBS in large cohorts and delineation of their phenotypic characteristics.

METHODS: We screened SALL1 and DACT1 variants using next-generation sequencing in the China Deafness Genetics Consortium (CDGC) cohort enrolling 20 666 unrelated hearing loss (HL) cases. Comprehensive clinical evaluations were conducted on seven members from a three-generation TBS family. Combining data from previously reported cases, we also provided a landscape of phenotypes and genotypes of patients with TBS.

RESULTS: We identified five novel and two reported pathogenic/likely pathogenic (P/LP) SALL1 variants from seven families. Audiological features in patients differed in severity and binaural asymmetry. Moreover, previously undocumented malformations in the middle and inner ear were detected in one patient. By comprehensive clinical evaluations, we further provide evidence for the causal relationship between SALL1 variation and certain endocrine abnormalities. Penetrance analysis within familial contexts revealed incomplete penetrance among first-generation patients with TBS and a higher disease burden among their affected offspring.

CONCLUSION: This study presents the first insight of genetic screening for patients with TBS in a large HL cohort. We broadened the phenotypic-genotypic spectrum of TBS and our results supported an underestimated prevalence of TBS. Due to the rarity and phenotypic heterogeneity of rare diseases, broader spectrum molecular tests, especially whole genome sequencing, can improve the situation of underdiagnosis and provide effective recommendations for clinical management.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:61

Enthalten in:

Journal of medical genetics - 61(2024), 5 vom: 19. Apr., Seite 459-468

Sprache:

Englisch

Beteiligte Personen:

Yan, Xiaohong [VerfasserIn]
Wang, Jing [VerfasserIn]
Yang, Wen [VerfasserIn]
Li, Linke [VerfasserIn]
Shen, Tian [VerfasserIn]
Geng, Jia [VerfasserIn]
Zhang, Qian [VerfasserIn]
Zhong, Mingjun [VerfasserIn]
Xiong, Wenyu [VerfasserIn]
Bu, Fengxiao [VerfasserIn]
Lu, Yu [VerfasserIn]
Zhao, Yu [VerfasserIn]
Cheng, Jing [VerfasserIn]
Yuan, Huijun [VerfasserIn]

Links:

Volltext

Themen:

Adaptor Proteins, Signal Transducing
DACT1 protein, human
Genetic Carrier Screening
Genetic Diseases, Inborn
Journal Article
Nuclear Proteins
Otolaryngology
Transcription Factors

Anmerkungen:

Date Completed 22.04.2024

Date Revised 26.04.2024

published: Electronic

Citation Status MEDLINE

doi:

10.1136/jmg-2023-109579

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM367859378