A family study of HLA antigens and other genetic markers in schizophrenia.

HLA antigens and 19 other genetic marker systems were studied in 12 families containing 2 or more members diagnosed as schizophrenic. In contrast with previous reports we could exclude linkage between the disorder and HLA, and we found no evidence of linkage with Gm or Gc. The disagreement between our results and those of a previous study, which suggested linkage between HLA and schizophrenia, could not be explained on the basis of genetic heterogeneity within the disorder. The problems of performing a linkage study in the face of diagnostic uncertainty and an unknown mode of inheritance of the main trait are discussed, and the measures taken in attempts to overcome these difficulties are described. Despite present drawbacks, genetic marker studies hold future promise as a means of detecting major gene effects in schizophrenia and other familial psychiatric disorders.