Personality disorder in young women with treated phenylketonuria.

Twenty-eight young women with phenylketonuria (PKU) attending a Maternal PKU Summer Camp were interviewed and administered a personality inventory, the Minnesota Multiphasic Personality Inventory (MMPI). The 12 young women who were either late-treated (treatment initiated after 90 days) or who had terminated the diet for a period of at least 5 years (the extended exposure group) were compared to the 16 women who were early-treated and had remained continuously on diet (the continuously treated group). Although the mean blood phenylalanine and tyrosine concentrations at the camp for the two groups were comparable (973 +/- 344 and 1033 +/- 284 mumol/L for phenylalanine and 43 +/- 16 and 40 +/- 25 mumol/L for tyrosine), the women in the extended exposure group evidenced significantly greater psychopathology as measured by the MMPI and self-report; thought disorder and mood disturbances were associated with diet termination in PKU.