Dr Karen Liddle1,2, Dr Rebecca Kriukelis1, Dr Rachael Beswick1
1Children’s Health Queensland, South Brisbane, Australia, 2Translational Research Institute, University of Queensland, Woolloongabba, Australia
Purpose:
To describe a cohort of paediatric patients from Queensland, Australia who have hearing loss(HL) as well as a pathological GJB2 variant and/or the common GBJ6 variant deletion (GJB6-D13S11830). The pathological variants and audiology profiles are described in order to determine if there are genotype-phenotype correlations in this population.
Nature and scope of the topic:
Retrospective analysis of statewide public pathology results and medical records of individuals with hearing loss and variants in GJB2 and /or the common GJB6 variant deletion (GJB6-D13S11830). The pathological variants as well as audiology profiles are also described to determine if there are genotype-phenotype correlations in this population.
Issue or problem under consideration:
The commonest causes of hearing loss in children are genetic factors, most frequently a single gene defect. The most common gene implicated in non-syndromic HL is GJB2 (encodes connexin 26). Mutations in this gene account for up to 50% of autosomal recessive HL cases described in the literature. However, GJB2 variants result in widely variable phenotypic profiles of hearing loss, often making it difficult to counsel patients around prognostication and management options. In addition, there are limited studies describing the genotype/phenotype profiles for patients from Oceania regions.
Outcome or conclusion reached:
The most common variant was GJB2 c.109G>A p.(Val37Ile), contributing to mostly mild degrees of hearing impairment. This is unique as, while seen in people of Asian descent, it is not usually the most common variant in European or Asian populations. Our findings align with the widely accepted notion that there is a wide degree of variability in genotype/phenotype findings for patients with GJB2 and GJB6 pathogenic variants and hearing impairment. This local information is helpful for both pre and postnatal genetic counselling.
Biography:
Dr Karen Liddle, MBBS FRACP MPH, is a Senior Staff Specialist Paediatrician at the Queensland Children’s Hospital and PhD candidate with the University of Queensland with the Integrating Genomics into Medicine Group. She has been clinically and developmentally assessing children with permanent hearing loss in the Childhood Hearing Clinic for twelve years. Her current research engages national and international collaborators to evaluate the utility of genetic testing and imaging in informing diagnoses and improving outcomes in childhood hearing loss. She is a member of the Childhood Hearing Australasia Medical Professionals (CHAMP) network and the Australasian Newborn Hearing Screening Committee.