GJB2 and MTRNR1 contributions in children with hearing impairment from Northern Cameroon.
OBJECTIVE
the aim of this work was to evaluate the possible different impacts of genetic and environmental factors in childhood deafness in northern Cameroon. GJB2 mutations are responsible for more than half of all cases of prelingual nonsyndromic recessive deafness in Caucasians, representing the most important deafness-causing factor in the industrialized world. Other genes such as MTRNR1 are also involved. In sub-Saharan Africa, environmental factors seem to dominate genetic contributions, but few studies on the etiology of deafness in Africa are available for comparison.


METHODS
prospective cross sectional study.


METHODS
we performed a molecular screen of the GJB2 and MTRNR1 genes in 70 deaf children and 67 unaffected controls in Maroua (Cameroon) and a literature analysis focused on deafness epidemiology in developing countries.


RESULTS
no GJB2 mutations emerged, and only a single MTRNR1 variant that may be pathogenic was found.


CONCLUSIONS
environmental factors turn out to be more relevant than genetic factor in the Maroua population.
Laboratory of Medical Genetics, Molecular Genetic Sector, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
Luca
L
Trotta
Elisabetta
E
Iacona
Paola
P
Primignani
Pierangela
P
Castorina
Chiara
C
Radaelli
Luca
L
Del Bo
Domenico
D
Coviello
Umberto
U
Ambrosetti
D002163:Cameroon; D002648:Child; D002675:Child, Preschool; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D003430:Cross-Sectional Studies; D003638:Deafness / Q000235:genetics*; D005260:Female; D050259:Genes, Mitochondrial; D006320:Hearing Tests; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012335:RNA, Ribosomal / Q000235:genetics*
D017630:Connexins; C000607042:GJB2 protein, human; D012335:RNA, Ribosomal; C075526:RNA, ribosomal, 12S; D000072259:Connexin 26