Evaluación de mutaciones en los genes GJB2 y GJB6 en pacientes con sordera congénita identificados mediante screening neonatal

摘要

If not detected and treated early, congenital sensorineural hearing loss generates impairment in linguistic, intellectual and social development of individuals. Most congenital hearing deficits are genetic. The most common causes are mutations in GJB2 and GJB6 genes, both located on chromosome 13, encoding junction proteins that allow the transduction of sound in the inner ear. Objetive: To evaluate the presence of mutations in GJB2 and GJB6 genes in a population of children diagnosed with deafness in Complejo Hospitalario Sótero del Río since implementation of the universal newborn hearing screening program. Patients and Methods: 8 patients with congenital nonsyndromic sensorineural deafness were evaluated. Genomic DNA was extracted from oral mucosa swabs. PCR was performed to identify the 35delG mutation in GJB2, followed by sequencing of this gene, and PCR for 2 GJB6 deletions. Results: Two patients were heterozygous for 35delG mutation in GJB2, being their other alleles normal. Another 2 patients were heterozygous for V27I polymorphism, one of them also accompanied by p.A148A (c.444C > A) variant. A patient was found with a previously undescribed mutation (c.4360 C>T) in GJB2's intron 1, being the second allele normal. No mutations were identified in GJB6. Conclusions: In this population of children, mutations in the GJB2 gene were an identifiable cause of congenital sensorineural.