An α-Tectorin Gene Defect Causes a Newly Identified Autosomal Recessive Form of Sensorineural Pre-Lingual Non-Syndromic Deafness, DFNB21

• Published in: Human molecular genetics Vol. 8; no. 3; pp. 409 - 412
• Main Authors: Mustapha, Mirna, Weil, Dominique, Chardenoux, Sébastien, Elias, Sanaa, El-Zir, Elie, Beckmann, Jacques S., Loiselet, Jacques, Petit, Christine
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.03.1999
• Subjects: Base Sequence; Biological and medical sciences; Chromosome Mapping; Chromosomes, Human, Pair 11 - genetics; Deafness - genetics; Deafness - physiopathology; DNA Mutational Analysis; DNA Primers - genetics; Ear, auditive nerve, cochleovestibular tract, facial nerve: diseases, semeiology; Extracellular Matrix Proteins - genetics; Female; Genes, Dominant; Genes, Recessive; Genetic Linkage; GPI-Linked Proteins; Heterozygote; Humans; Lebanon; Male; Medical sciences; Membrane Glycoproteins - genetics; Non tumoral diseases; Otorhinolaryngology. Stomatology; Pedigree; Phenotype; Point Mutation; Lebanon; Genetic mapping; Human; Membrane protein; Gene; Family study; Auditory disorder; ENT disease; Mutation; Chromosome C11; Tectorial membrane; Hearing loss
• DOI: 10.1093/hmg/8.3.409
• ISSN: 0964-6906; 1460-2083

In our efforts to identify new loci responsible for non-syndromic autosomal recessive forms of deafness, DFNB loci, we have pursued the analysis of large consanguineous affected families living in geographically isolated areas. Here, we report on the study of a Lebanese family comprising nine members presenting with a pre-lingual severe to profound sensorineural isolated form of deafness. Linkage analysis led to the characterization of a new locus, DFNB21, which was assigned to chromosome 11q23–25. Already mapped to this chromosomal region was TECTA. This gene encodes α-tectorin, a 2155 amino acid protein which is a component of the tectorial membrane. This gene recently has been shown to be responsible for a dominant form of deafness, DFNA8/12. Sequence analysis of the TECTA gene in the DFNB21-affected family revealed a G to A transition in the donor splice site (GT) of intron 9, predicted to lead to a truncated protein of 971 amino acids. This establishes that α-tectorin mutations can be responsible for both dominant and recessive forms of deafness. Comparison of the phenotype of the DFNB21 heterozygous carriers with that of DFNA8/12-affected individuals supports the hypothesis that the TECTA mutations which cause the dominant form of deafness have a dominant-negative effect. The present results provide genetic evidence for α-tectorin forming homo- or heteromeric structures.