Genetic screening for mental retardation in Michigan

The Michigan Department of Mental Health established a genetic screening laboratory in 1977 to provide diagnostic information on retarded patients. Of 727 patients screened during a 2-year period, a genetic diagnosis was established for 121 moderately to severely retarded patients. Genetic counseling was provided for 40 percent of their parents. A wide variety of chromosomal abnormalities, inborn errors of metabolism, and dysmorphic syndromes was discovered, including 16 instances of previously unknown familial conditions. This program has demonstrated a cost-effective method for determining genetic etiology in mental retardation and, in some instances, has led to prevention of mental retardation.