EVALUATION OF DOPAMINERGIC SYSTEM GENES I N MEXICAN SCHIZOPHRENICS

This investigation reports an association study with alleles of the do paminergic system genes (tyrosine hydroxylase (TH), D2 and D4 receptor s) in schizophrenic patients and non-schizophrenic subjects. The genot ypes were typed using a polymerase chain reactions PCR-based CA repeat polymorphisms. There were no significant associations between the stu died alleles and schizophrenia. Also, a linkage analysis was performed using the same genes (TH, D2 and D4) in two multiple affected schizop hrenic families. There was no linkage among any of three genes and sch izophrenia. The maximum lod score (Z = 0.43, theta = 0.10 penetrance 1 00%) was for the tyrosine hydroxylase gene. Linkage analysis significa ntly excluded the D2 receptor gene (Z = 5.6, theta = 0.01), assuming a n autosomal dominant pattern and complete penetrance, However, when th e lod scores were calculated with other penetrance values, they lost s ignificance.