The advances made in studies on the molecular biology of the dopamine
transporter (DAT) and receptors (D1, D2, D3, D4 and D5) are reviewed,
and their pharmacological characteristics and the relationship between
polymorphic variations of these human proteins and neuropsychiatric d
isorders are discussed. Data from four studies on the variants of the
D2 receptor gene (Ser(311)-->Cys), BalI polymorphism in D3, 48-base re
peat polymorphism in D4, and 40-base repeat polymorphism in the DAT ge
ne in patients with schizophrenia, mood disorder, neurological disease
and controls are reported.