EXCLUSION OF 5 TRINUCLEOTIDE REPEAT (CAG AND CCG) EXPANSIONS IN 17 FAMILIES WITH SCHIZOPHRENIA

Trinucleotide repeat expansion diseases ar characterized by anticipati on. Several studies suggested the anticipation in schizophrenia. We st udied five novel trinucleotide repeats identified by Li et al in a hum an brain cDNA library in 100 unrelated control subjects, and 57 subjec ts in 17 families with schizophrenia. The CTG-B43 and B45d, and CCG-A3 were not polymorphic in any unrelated control subjects or subjects wi th familial schizophrenia. The CTG-A4 had two alleles and the CTG-B1 t hree alleles. The two clones were not expanded in subjects with famili al schizophrenia or unrelated healthy controls. There was no differenc e in allele frequency between unrelated control subjects and subjects in the families with schizophrenia. The allele frequencies in unaffect ed and affected subjects in the families with schizophrenia were not s ignificantly different. There was no difference between the offspring and parental generations of affected subjects in the families with sch izophrenia. The results suggest the exclusion of the five trinucleotid e repeat expansions in the 17 families with schizophrenia. (C) 1997 So ciety of Biological Psychiatry.