Population-Specific Mutational Spectrum of Autosomal Recessive Nonsyndromic Hearing Loss in Croatian Roma: Implications for Clinical Genetics.

BACKGROUND/

OBJECTIVES

Hearing impairment is a highly prevalent sensory disorder resulting from a variety of causes. A high proportion of autosomal recessive non-syndromic hearing impairment is linked to the GJB2 (OMIM 121011) gene which encodes for a gap junction protein, connexin-26. Alterations of genes that encode for connexins can lead to changes in cell ion content and cause hearing impairment.

METHODS

GJB2 gene polymorphisms (c.71G>A, p.Trp24*rs104894396; c.457G>A, p.Val153Ile, rs111033186; c.380G>A, p.Arg127His, rs111033196; c.109G>A, p.Val37Ile, rs72474224; and c.269T>C, p.Leu90Pro, rs80338945) were analyzed in the Roma population of Croatia. Loci were genotyped using the KASP method.

RESULTS

Altered alleles were detected on the loci c.71G>A, c.457G>A and c.380G>A and statistically significant differences in allele frequencies were noticed. Furthermore, in comparison to worldwide populations, the Roma population also shows statistically significant difference in allele frequency of these loci.

CONCLUSIONS

This study reveals marked genetic differentiation among Croatian Roma particularly with respect to the c.71G>A variant. Characterizing such population-specific mutational heterogeneity is crucial for the accurate prevention, diagnosis, and clinical management of autosomal recessive nonsyndromic hearing loss.