Structure, genetic localization, and identification of the cardiac and skeletal muscle transcripts of the human integrin alpha 7 gene (ITGA7)

We have determined the structure and the exon size pattern of the human int egrin alpha 7 subunit gene (ITGA7), which has been shown to be affected in a form of congenital myopathy. The gene is composed of at least 27 exons sp anning a region of about 22.5 kb. The sequence of all exon/intron boundarie s was determined and conforms to the GT/AG splicing consensus. We investiga ted the different splicing forms previously described in human and rodents. The major cytoplasmic variants alpha 7A and alpha 7B, which are developmen tally regulated and tissue specific, were identified in human tissues, as w ell as the extracellular isoforms X1 and X2. The recently described D varia nt was detected in adult tissues by RT-PCR but not the C variant. We locali zed ITGA7 on chromosome 12q13 by high-resolution radiation hybrid mapping b etween D12S312 and D12S90 and identified a new CA-repeat microsatellite in intron 1. (C) 1999 Academic Press.