Controlled family studies of schizophrenia and of bulimia are underway. In the schizophrenia study 51 patients and 28 normals have been interviewed, as well as 136 of their relatives; the bulimia study is in the planning stage. Family study of affective disorders suggests that a restrictive definition of major depression, which requires impairment or incapacitation in the person's major social role, may usefully identify cases with a familial, presumably genetic vulnerability. Two new polymorphisms have been identified on two-dimensional electrophoretic gels bringing the total number identified to 27, and two new linkages of new protein polymorphisms to known markers were identified. Other analytic methods assign a mixed single-locus/polygenic inheritance mode to catechol-O-methyltransferase and to dopamine beta-hydroxylase. Previously, only the single locus component to their inheritances was known. Receptor-like characteristics identified on adult skin fibroblasts include specific and saturable binding of vasoactive intestinal peptide (VIP), as well as VIP stimulated release of arachadonic acid. Somatostatin (SRIF) shows specific binding, as well as inhibition of cyclic guanine monophosphate (cGMP) production in these cells. Muscarinic receptor-like characteristics, at this point, are confined to antagonist binding. In other studies, heritability of forskolin-stimulated but not hormone stimulated adenylate cyclase in lymphocytes was demonstrated.
