LOCALIZATION OF A GENE CAUSING CYSTINURIA TO CHROMOSOME 2P

Cystinuria is an autosomal recessive disorder of amino acid transport. It is a common hereditary cause of kidney stones worldwide, and is as sociated with significant morbidity. in 17 affected families, we found linkage between cystinuria and three chromosome 2p markers. Maximal t wo-point rod scores between cystinuria and D2S119, D2S391 and D2S288 w ere 8.23 (theta=0.07), 3.73 (theta=0.15) and 3.03 (theta=0.12), respec tively. Analysis of recombinants and multipoint linkage data indicated that the most likely order is cen-D2S391-D2S119-cystinuria-D2S177-tel . We also observed high rates of homozygosity for markers in this chro mosomal region among 11 affected offspring of consanguineous marriages . Based on its map position and function, the recently cloned SLC3A1 a mino acid transporter gene is a primary candidate gene for this diseas e.