No evidence for linkage by transmission disequilibrium test analysis of microsatellite marker D22S278 and schizophrenia in a Palestinian Arab and in a German population

Linkage for a schizophrenia susceptibility locus on chromosome region 22q12 -q13 was initially suggested by independent studies from two groups and con firmed in a combined analysis of data for the microsatellite marker D22S278 in multiply affected schizophrenic families derived from 11 independent re search groups worldwide. In addition to these reports of linkage 60 schizop hrenia on chromosome 22, bipolar disorder has also been linked to markers i n this chromosomal region. We now report results from an analysis of 223 Pa lestinian Arab trios from three different centers in Israel and Palestine u sing the allele-wise extended transmission disequilibrium test for multiall elic markers. No evidence for linkage is observed in the entire group or in any of the three centers (entire group: chi-square = 5.59, P = 0.78, df = 9; Afula: chi-square = 6.51, P = 0.48, df = 7; Bethlehem: chi-square = 14.1 1, P = 0.12, df = 9; Beersheva: chi-square = 7.04, P = 0.32, df = 6). Addit ionally, we examined D22S278 in a group of 114 schizophrenic German triads and failed to observe evidence for linkage (chi-square = 8.13, P = 0.42, df = 8df). (C) 2001 Wiley-Liss, Inc.