In the fetal genomes of 6 different families, we identified autosomal recessive deafness alleles in the genes GJB2 and TMPRSS3
; these alleles are known to be more prevalent in Asian populations.
Screening for the SLC26A4 (NM_000441.1), MYO7A (NM_000260.3), MYO15A (NM_016239.3), OTOF (NM_194248.2), CDH23 (NM_022124.5), TMIE (NM_147196.2), TECTA (NM_005422.2), PCDH15 (NM_033056.3), TMC1 (NM_138691.2), TMPRSS3 (NM_024022.2), LHFPL5 (NM_182548.3) genes was performed using the open array method (TaqManR OpenArrayR) in 12 families in whom m.
Homozygosity was seen in the OTOF gene in family number 909 (Table 2b), in the TMPRSS3 gene in family number 910 (Table 2c), and in the OTOF, TMPRSS3, and TMHS genes in family number 917 (Table 2d, 2e, 2f).
In our study, segregation was found in the TMPRSS3 gene in two families.
(37) in the Turkish population, families with consanguineous marriage and with at least three children with hearing loss were screened and mutations in the TMPRSS3 gene were found with a frequency of 1.7%.
Individuals with mutations in TMPRSS3 (transmembrane protease, serine 3) present with two different phenotypes: DFNB10-associated hearing impairment that is prelingual (OMIM 605511) and DFNB8-associated hearing impairment that is typically late onset and postlingual (OMIM 601072).
Although several causative mutations in TMPRSS3 have been identified, little is known about the contribution of this gene to ARNSHL in the Chinese population.
Mutational Detection and Analysis of TMPRSS3. All of the 13 exons and 100 bp of exon-intron boundaries of TMPRSS3 (NM_024022.2) were screened via Sanger sequencing of DNA from 150 index patients of ARNSHL families.
DNA samples (23) from six families were haplotyped using six STR markers (D21S266, D21S1260, D21S2092, D21S1225, D21S1411, and D21S1890) within a 1 Mb region surrounding TMPRSS3 Ala306, as previously described (Table 1) .
Exceptions were observed in the TMPRSS3 gene, which was reported to be associated with two different phenotypes: DFNB10-associated hearing impairment has been reported to be prelingual (OMIM 605511), whereas DFNB8-associated hearing impairment is typically late onset and postlingual (OMIM 601072).
We performed large-scale mutational screening of 129 known deafness-related genes and identified three disease-segregating mutations in the TMPRSS3 gene: two previously reported missense mutations, c.916G>A (p.Ala306Thr) and c.316C>T (p.Arg106Cys), and one novel mutation, c.36delC [p.(Phe13Serfs*12)].
Mutational Detection and Analysis of TMPRSS3. The segregation of the TMPRSS3 c.916G>A (p.Ala306Thr), c.36delC [p.(Phe13Serfs*12)], and c.316C>T (p.Arg106Cys) mutations was tested in seven family members (II: 2, II: 3, II: 5, III: 2, III: 3, III: 4, and IV: 1), including the four whose gDNA had been subjected to the 129 deafness-associated genes and next-generation sequencing (NGS) analysis, using polymerase chain reaction (PCR) (primer sequences available on request) followed by bidirectional Sanger sequencing of the amplified fragments (ABI 3100; Applied Biosystems).