Autosomal and X-Linked Auditory Disorders - Genetics of Auditory Disorders - page 135

TABLE 6.3. X-linked nonsyndromic deafness loci (DFN)
Locus

Location Onset of Hearing Loss in Males Additional Comments about Phenotype Selected References

DFN1/ Xq22 Early onset to 1.5 yrs Progressive SNHL in males; 80 dBHL by age 13 yrs. Tranebjaerg et al. 1995

MTS a accompanied by variation in spasticity, dystonia, Jin et al. 1996

ataxia, mental retardation, hip fractures and Koehler et al. 1999

progressive visual disability leading to blindness;
mild or no hearing loss in females

DFN2 Xq22 Congenital Profound SNHL in males; mild to moderate hearing Tyson et al. 1996

loss in female carriers

DFN3 Xq13-q21.1 Infancy Progressive MHL in males, with or without stapes de Kok et al. 1995

fixation; perilymphatic gusher upon stapes surgery de Kok et al. 1996

Minowa et al. 1999

DFN4 Xp21.2 Congenital Profound SNHL in males; variable expression in Lalwani et al. 1994

carrier females Pfister et al. 1998

Pfister et al. 1999

DFN6 Xp22 Postlingual to 5-7 yrs Progressive SNHL in males mainly affecting high del Castillo et al. 1996

frequencies evolving to severe to profound loss at
all frequencies in adulthood; incomplete penetrance
and variable expression in female carriers

a See Mohr-Tranebjaerg syndrome in Table 6.5, since DFN1 was shown to be syndromic. Abbreviations: SNHL, sensorineural hearing loss; MHL, mixed
hearing loss; dBHL, decibels hearing loss