CHARACTERIZATION OF THE HUMAN HOMOLOG OF THE MOUSE TG737 CANDIDATE POLYCYSTIC KIDNEY-DISEASE GENE

We previously identified a gene from the mutant locus in a new mouse m utation that causes recessive polycystic kidney disease. Here we descr ibe the cloning, characterization and mapping of the homologous human gene. The human and mouse genes are 95% identical at the predicted ami no acid sequence level, and both genes encode a putative protein that contains a tetratricopeptide repeat motif. The human gene, called hTg7 37, is expressed with a broad tissue distribution that includes the ki dney and liver, and gives rise to a 2.9 kb mRNA. The gene contains 26 exons and spans a genomic region greater than 100 kb. Chromosome mappi ng experiments revealed that the hTg737 gene maps near the centromere on the long arm of human chromosome 13, at position 13q12.1. While thi s gene does not map to the primary locus that has been identified for ARPKD in humans, it may represent a candidate gene for other recessive renal disorders that have yet to be mapped.