Neurosensory hearing loss in secondary adhalinopathy

We report mild-to-moderate neurosensory hearing loss and severe childhood autosomal recessive muscular dystrophy with adhalin-deficiency in two siblings from a Bulgarian sibship of Turkish origin. Microsatellite analysis excluded linkage to the adhalin gene, mutations of which cause limb girdle muscular dystrophy (LGMD) 2D, but was compatible with linkage to the gene locus of LGMD 2C on chromosome 13q12. Compound heterozygosity of the affected siblings was detected in this chromosomal region. A severe autosomal recessive form of neurosensory deafness has been linked to the same region (locus NSRD1) which is now contained in a 7 Mb YAC contig. Using polymorphic markers and STS PCR primers mapping in this contig, we did not find evidence for major rearrangements in the suspected region. These preliminary findings are not in favor of, but do not completely exclude a contiguous gene syndrome in these cases. Therefore, we consider a potential role of the putative 13q12 gene product and/or adhalin in neurosensory hearing.