Effects of Untreated Maternal Phenylketonuria and Hyperphenylalaninemia on the Fetus

Abstract

To the Editor: The report by Levy and Waisbren on the effects of untreated maternal hyperphenylalaninemia on the fetus (Nov. 24, 1983, issue)¹ represents a major attempt to delineate this problem in a population identified by routine screening, As such, the findings should be a lodestone for counseling similar cases. However, Levy and Waisbren's results differ so radically from those in the earlier survey by Lenke and Levy² that we must examine both critically. It seems certain that the original survey suffered from biased ascertainment, which contributes to the current gloomy prediction for hyperphenylalaninemic mothers. The new data suggest that . . .