The deafness-causing mutation c.508_511dup in the GJB2 gene and a literature review

Abstract

Conclusions: The mutation c.508_511dup in GJB2 gene has been incorrectly named as other mutations. It is essential to standardize mutation nomenclature to describe complex mutations. Objectives: This paper aimed to verify a series of patients with the frame-shift mutation c.508_511dup in the GJB2 gene and review the literature on related mutations. Methods: All the included patients with non-syndromic hearing loss (NSHL) carried the 504insAACG or c.508_511dup mutation of the GJB2 gene in the present study. Their parents were encouraged to participate. After written informed consent and clinic data had been obtained, genomic DNA was extracted from venous blood of participants. The target fragments were amplified by polymerase chain reaction (PCR) and subjected to bidirectional sequencing to identify sequence variations. Results: A total of 14 patients with prelingual NSHL and 6 normal parents were recruited. Genotyping revealed that one mutation, c.508_511dup (not 504insAACG), was homozygous in 1 patient, heterozygous in 2 patients and 3 parents, and compound heterozygous in 11 patients. Twelve patients had hearing loss caused by c.508_511dup in a homozygous or compound heterozygous form, and further study showed that it was wrongly named as 504insAACG. Additionally, according to the standard nomenclature, the previously reported mutations with distinct names from the literature review may be replaced by c.508_511dup.

Keywords:

• Frame-shift mutation
• GJB2, hearing loss
• nomenclature

Acknowledgments

This work was supported by grants from the National Natural Science Foundation of China (General Program nos 81172765 and 30771857). We are indebted to the participating people and their family members for their cooperation during this study.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.