TY - JOUR T1 - Autosomal recessive non-syndromic hearing loss in the Lebanese population: prevalence of the 30delG mutation and report of two novel mutations in the connexin 26 (<em>GJB2</em>) gene JF - Journal of Medical Genetics JO - J Med Genet SP - e36 LP - e36 DO - 10.1136/jmg.38.10.e36 VL - 38 IS - 10 AU - Myrna Mustapha AU - Nabiha Salem AU - Valérie Delague AU - Eliane Chouery AU - Michella Ghassibeh AU - Myriam Rai AU - Jacques Loiselet AU - Christine Petit AU - André Mégarbané Y1 - 2001/10/01 UR - http://jmg.bmj.com/content/38/10/e36.abstract N2 - Editor—The most common sensory deficit in humans is hearing loss, affecting 1 in 1000 children, with approximately half of the cases having a genetic cause. The majority of these genetic causes are non-syndromic, of which approximately 75% have an autosomal recessive mode of inheritance.1 So far, nearly 30 genes that cause non-syndromic recessive deafness (NSRD) have been located (for review see http://dnalab-www.uia.ac.be/dnalab/hhh). The loci corresponding to NSRD are designated DFNB, with a number corresponding to the chronology of their localisation. The first locus, DFNB1 (MIM 220290), located on chromosome 13q11-12,2 has been shown to be responsible for nearly half of NSRD owing to mutations in the gene encoding the gap junction protein connexin 26 (GJB2) (MIM 121011).3 4 One mutation, 30delG (also referred to as 35delG), accounts for the majority of mutations in this gene in some ethnic groups,3-8 while it is rarer in others.9-15 The geographical position of Lebanon, a small country of 10 500 km2 on the eastern shores of the Mediterranean sea, has made it a historical crossroads between Asia, Africa, and Europe. As a consequence, the Lebanese population shows a wide genetic diversity, with no less than 17 ethno-religious communities. Today, the population is approximately 4 million people, with a world wide diaspora estimated at 15 million. In Lebanon, consanguineous marriages are still frequent (from 10 to 30%), favouring the incidence of autosomal recessive diseases,16 such as haemoglobinopathies, sickle cell anaemia, familial Mediterranean fever, congenital hypothyroidism, cystic fibrosis, and deafness.The purpose of this study is to summarise the different NSRD loci found in a case series of Lebanese families and to determine the carrier frequency of the 30delG mutation in selected Lebanese subjects. Forty eight multiplex Lebanese families with non-syndromic congenital moderate to profound deafness, from various … ER -