Association between GABA-A receptor alpha 5 subunit gene locus and schizophrenia of a later age of onset

Heritability is considered to be a major etiologic factor for schizophrenia . Among the genes considered as candidates for the disease, are those relat ed to GABAergic neurotransmission, Our aim was to test for a genetic associ ation between GABA-A receptor alpha 5 subunit gene locus (GABRA(5)) and sch izophrenia. Genotyping of the GABRA(5) locus was performed by the use of a dinucleotide (CA) repeat marker in 46 schizophrenic patients and 50 healthy individuals, all unrelated Greeks. Eight alleles were identified, 276-290 bp long. A nonsignificant excess of the 282-bp allele, which was found in a previous study in a Greek population to be associated with bipolar affecti ve disorder, was observed in schizophrenic patients (33.8 vs. 23.9% in the controls). The frequency of this allele was 43.3% among patients with a lat er age of onset lover 25 years), differing at a statistically significant l evel from the controls (p < 0.05). These results suggest that common pathop hysiological mechanisms may possibly underlie affective disorders and schiz ophrenia, at least in a subgroup of patients. Copyright (C) 2001 S. Karger AG. Basel.