Physical and transcriptional map of the hereditary inclusion body myopathylocus on chromosome 9p12-p13

Hereditary inclusion body myopathy (HIBM) is a group of neuromuscular disor ders characterised by adult onset, slowly progressive distal and proximal m uscle weakness and typical muscle pathology. Previously, we have mapped the gene responsible for a recessive form of HIBM to chromosome 9p1 and narrow ed the interval to one single YAC clone of 1 Mb in size. As a further step towards the identification of the HIBM gene, we have constructed a detailed physical and transcriptional map of this region. A high resolution BAC con tig that includes the HIBM critical region, flanked by marker 327GT4 and D9 S1859, was constructed. This contig allowed the precise localisation of 25 genes and ESTs to the proximal region of chromosome 9. The expression patte rn of those mapped genes and ESTs was established by Northern blot analysis . In the process of refining the HIBM interval, 13 new polymorphic markers were identified, of which I I are CA-repeats, and two are single nucleotide polymorphisms. Certainly, this map provides an important integration of ph ysical and transcriptional information corresponding to chromosome 9p12-p13 , which is expected to facilitate the cloning and identification not only o f the HIBM gene, but also other disease genes which map to this region.