RESUMEN
Introduction: Hearing loss is one of the most prevalent congenital sensory disorders. Over 50% of congenital hearing loss cases are attributed to genetic factors. The PTPRQ gene encodes the protein tyrosine phosphatase receptor Q, which plays an important role in maintaining the structure and function of the stereocilia of hair cells. Variants in the PTPRQ gene have been implicated in hereditary sensorineural hearing loss. Methods and Results: Utilizing next-generation sequencing technology, we identified novel compound heterozygous variants (c.977G>A:p.W326X and c.6742C>T:p.Q2248X) in the PTPRQ gene within a Chinese national lineage, marking the first association of these variants with hereditary sensorineural hearing loss. Discussion: Our findings further emphasize the critical role of PTPRQ in auditory function and contribute to a more comprehensive understanding of PTPRQ-associated hearing loss mechanisms, aiding in clinical management and genetic counseling.
RESUMEN
BACKGROUND: The Protein tyrosine phosphatase receptor Q (PTPRQ) gene encodes a member of the type III receptor-like protein tyrosine phosphatase family found in the stereocilium. Mutations in PTPRQ are mostly associated with deafness, autosomal recessive type 84 (DFNB 84), which usually results in progressive familial hearing loss. METHODS: A 25-year-old woman and her sister, both with postlingual-delayed progressive sensorineural hearing loss, were examined. They were from a nonconsanguineous marriage and had no family history of hearing loss. New compound heterozygous PTPRQ gene mutations, nonsense (c.90C > A, p.Y30X) and splice (c.5426 + 1G > A) mutations in two PTPRQ alleles, were identified in the two sisters and were presumably autosomal recessive. The c.90C > A (p.Y30X) mutation was mapped to exon 2 of PTPRQ (NM_001145026). RESULTS: The c.90C > A mutation leads to a premature stop codon and a truncated protein. The c.5426 + 1G > A mutation leads to a truncated protein lacking the extracellular domain. Hence, both mutations were predicted to be pathogenic, leading to a deficiency of the extracellular, transmembrane, and phosphatase domains because of nonsense-mediated mRNA degradation. CONCLUSIONS: This study increases the spectrum of PTPRQ gene mutations that might be involved in delayed progressive autosomal recessive non-syndromic hearing loss.