Wajid et al. (2003) reported a consanguineous Pakistani family in which several members had an autosomal recessive form of profound prelingual sensorineural deafness involving all frequencies. Affected individuals used sign language for communication.
Schultz et al. ... Wajid et al. (2003) reported a consanguineous Pakistani family in which several members had an autosomal recessive form of profound prelingual sensorineural deafness involving all frequencies. Affected individuals used sign language for communication. Schultz et al. (2009) examined 2 affected members from each of 39 Pakistani and 2 Indian families segregating recessive deafness mapping to the DFNB39 locus. Pure-tone audiometry revealed prelingual, bilateral, and severe-to-profound hearing loss, with a downward-sloping audiometric configuration. Bone conduction threshold testing in some individuals confirmed a sensorineural etiology, but mixed-hearing loss could not be ruled out in others. Some affected individuals from 2 families ('PKDF210' and 'PKDF601') had a slightly milder phenotype characterized by moderately severe hearing loss at low frequencies. General physical examination of affected individuals showed no other abnormalities.
Schultz et al. (2009) sequenced the coding regions of 13 genes within the DFNB39 locus on chromosome 7q11.22-q21.12 in 11 DFNB39 families, but found no missense, nonsense, or frameshift mutations; analysis of the noncoding regions of the genes ... Schultz et al. (2009) sequenced the coding regions of 13 genes within the DFNB39 locus on chromosome 7q11.22-q21.12 in 11 DFNB39 families, but found no missense, nonsense, or frameshift mutations; analysis of the noncoding regions of the genes revealed 3 potential regulatory mutations in the HGF gene (142409.0001-142409.0003) that segregated with deafness. Examination of the inner ear in transgenic mice showed that overexpression of Hgf is associated with progressive degeneration of outer hair cells in the cochlea, whereas cochlear deletion of Hgf is associated with more general dysplasia.