EVIDENCE AGAINST UNUSUAL SEX CONCORDANCE AND PSEUDOAUTOSOMAL INHERITANCE IN THE CATATONIC SUBTYPE OF SCHIZOPHRENIA

The study is based on sibships with multiply afflicted members derived from a family study of consecutively admitted probands with catatonic schizophrenia. As shown recently, the clinical subtype of periodic ca tatonia, as defined by Leonhard, is compatible with a major gene effec t and genetic anticipation; that is, the age of illness onset of the p robands is significantly earlier than that of their parents. In the pr esent study, 83 probands with the clinical subtype of periodic cataton ia had 26 afflicted siblings that were distributed among 23 families. We analyzed sex-concordance and pseudoautosomal inheritance patterns. Stratifying the 26 afflicted siblings by sibship size and by the proba nd's sex, we did not find unusual sex-concordance rates in sibships af flicted with periodic catatonia. Further, there was no association bet ween sex concordance and maternal or paternal origin of the disease. T hus, our results provide strong evidence against pseudoautosomal inher itance or sex-linked transmission in affected sibships in the obviousl y familial schizophrenic subtype of periodic catatonia.