The SH2D2A gene encoding the T-cell-specific adapter protein (TSAd) is localized centromeric to the CD1 gene cluster on human Chromosome 1

The SH2D2A gene encoding the T-cell-specific adapter protein (TSAd), was is olated from a human Chromosome (Chr) 1 cosmid library (LLNL, UK HGMP). The gene spans 11 kilobases and contains nine exons and eight introns. Four alt ernative transcript variants were observed in activated T cells. Three sing le-nucleotide polymorphisms were identified within intron 2. A variable num ber of GA repeats was found at position -340 from the first coding ATG. Lin kage analysis using this marker in eight CEPH families showed that the SH2D 2A gene is located close to the D1S2624 marker on Chr 1q21-1q22. Physical m apping of a PAC and BAC contig containing the CD1 gene cluster telomeric to D1S2624 failed to identify a clone harboring the SH2D2A gene. Thus the SH2 D2A gene is located centromeric to the CD1 gene cluster on Chr 1.