Disease relevance of DFNA25

• DFNA25, a novel locus for dominant nonsyndromic hereditary hearing impairment, maps to 12q21-24 [1].
• CONCLUSIONS: It is difficult to differentiate delayed-onset high-frequency sensorineural hearing loss inherited as a simple mendelian trait like DFNA25-associated hearing loss from that due to noise exposure or presbycusis, disorders that may also have a genetic component [2].

High impact information on DFNA25

• Using linkage analysis, we identified a novel dominant locus, DFNA25, for delayed-onset, progressive, high-frequency, nonsyndromic sensorineural hearing loss in a large, multigenerational United States family of Czech descent [1].
• On the basis of recombinations in affected individuals, we determined that DFNA25 is located in a 20-cM region of chromosome 12q21-24 between D12S327 (centromeric) and D12S84 (telomeric), with a maximum two-point LOD score of 6.82, at recombination fraction.041, for D12S1030 [1].
• OBJECTIVES: To clinically characterize a family with nonsyndromic sensorineural hearing loss linked to the DFNA25 gene and to assess whether mitochondrial mutations influence the penetrance of the phenotype [2].

Biological context of DFNA25

• In those inheriting the DFNA25-associated haplotype from an affected mother, hearing loss invariably developed by the second decade of life, whereas those inheriting the DFNA25 haplotype from an affected father often maintained hearing levels comparable to those of age-matched control subjects, even into the seventh decade of life [2].

References