The hypoacusia can be classified in two clinical forms: Syndromic (SHL) and Nonsyndromic
(NSHL). In particular, the NSHL describes the 70–80% of hypoacusia cases and it
is mainly due to genetic factors, which are causative of the deafness at the birth. The genetic
hypoacusia presents different inheritance patterns: autosomal dominant (20%), autosomal
recessive (80%), X-linked (1%), and mitochondrial (1%), respectively. To date, about
35 deafness-causative genes have been identified and most of them codify for connexin
transmembrane proteins. Approximately 1:2500 children with NSHL carries mutations
in the GJB2 and GJB6 (13q12) genes, which code for connexin 26 (Cx26) and connexin
30 (Cx30), respectively. In the Caucasian population, the most common mutations are
35delG, M34T and 167delT, and D13S1830. Given the frequency distribution of the four
mutations in the Caucasian population and the pathogenic connection with NSHL, the
development of accurate, rapid, and “low-cost” molecular assays should be strongly encouraged.
To this purpose, we set up two different molecular assays (namely the Cx26
and Cx26-30 molecular assays) for the fast and inexpensive detection of 35delG, M34T,
167delT, and D13S1830 mutations. Both the molecular approaches showed to be accurate,
sensitive, reproducible, and “low-cost” alternatives for the proper evaluation of the GJB2
and GJB6 genes, which are causative ofNSHL. In conclusion, the Cx26 and Cx26-30 molecular
assays can be applied to individual, preconception, prenatal, or postnatal screening
for the causative-mutations of NSHL