THE GENE ENCODING A CATIONIC AMINO-ACID TRANSPORTER (SLC7A4) MAPS TO THE REGION DELETED IN THE VELOCARDIOFACIAL SYNDROME

By screening an expressed sequence tag database, we identified a novel human gene, SLC7A4, encoding a solute carrier family 7 [cationic amin o acid (CAA) CAT-4 transporter, y(+) system] member 4. The SLC7A4 cDNA is 2325 nt long and includes 78, 1911, and 336 nt in the 5' noncoding , coding, and 3'-noncoding regions, respectively. SLC7A4 displays high homology with SLC7A1 and SLC7A2, two previously known CAA transporter s. By chromosomal in situ hybridization and YAC identification, SLC7A4 was mapped to 22q11.2, the commonly deleted region of the velocardiof acial syndrome (VCFS, Shprintzen syndrome). In a patient affected by V CFS, deletion of SLC7A4 was demonstrated by chromosomal FISH. By North ern analysis, an abundant transcript was detected in brain, testis, an d placenta. Microinjection of SLC7A4 mRNA into Xenopus laevis oocytes demonstrates a significant stimulation of CAA transport. (C) 1998 Acad emic Press.