Pittsburgh Registry of Infant Multiplets (PRIM): an update.

This article is an updated review of the Pittsburgh Registry of Infant Multiplets including recruitment methods, data collection, and results of pilot studies conducted in this registry. The main goal of the registry is to study psychological development. The risk for behavior disorders including substance use disorders, as well as language development and dental health are among research targets. Pilot data on the heritability of minor physical anomalies and neuropsychological characteristics (Continuous Performance Test) are reported.