Audiological characteristics of the Monge family of Costa Rica

Abstract

The audiological characteristics of the Monge family of Costa Rica were investigated in a sample of fifty-two affect-

Further Characterization of the DFNA1 Audiovestibular Phenotype

“…The audiometric series from subject 3 (Figure) is typical of disease progression in this family; nonetheless, there is variability in the rate of progression of hearing loss among affected family members. 11,13,14 Because of the heterogeneity in the hearing impairment with respect to age at onset and the rate of auditory deterioration, pure-tone losses of 50 dB at 250 Hz and 500 Hz by age 30 years have been established as a minimal criterion for affected status in this family based on audiologic and genetic data. The abnormal gene is fully penetrant: all family members who carry the DFNA1 mutation are affected by age 30 years.…”

“…Routine audiometric evaluation of this family showed that the hearing impairment begins in childhood, initially involves the low tones, and progresses to involve the middle and high frequencies in the second to third decade of life. 11,13,14 The hearing loss is mild at onset and profound by adulthood, involving both ears. The ratio of affected to unaffected children of deaf parents is 1:1; males and females are equally likely to be affected.…”

Audiological Aspects of “Monge Deafness”

“…Such damage was appointed by the International Commission of gene nomenclature as DFNA1 (DFN is an abbreviation of deafness word deafness in English and A1, which means prevail autosomal dominant gene). Today there are over 100 individuals carriers of this disorder [1][2][3][4][5].…”