LINKAGE STUDY OF THE D-5 DOPAMINE-RECEPTOR GENE (DRD5) IN MULTIPLEX ICELANDIC AND ENGLISH SCHIZOPHRENIA PEDIGREES

Objective: The authors investigated the possibility that genetic varia tion or mutation of the dopamine D-5 receptor gene might modify suscep tibility to schizophrenia. Method: Twenty-three Icelandic and English pedigrees containing multiple cases of schizophrenia were genotyped by using a highly informative microsatellite for the D-5 dopamine recept or gene DRD5. Results: By means of three different affection models, n egative lod scores were obtained under assumptions of autosomal domina nt and recessive inheritance. There was no evidence for locus heteroge neity. Nonparametric extended relative pair analysis also produced neg ative results. Conclusions: These data indicate that mutations of the D-5 dopamine receptor gene ave not a major cause of schizophrenia in t hese pedigrees. Because of the probable existence of locus heterogenei ty, the D-5 receptor gene may be of etiologic importance in other fami lies with schizophrenia.