Clinical Trial: Low Phenylalanine Diet for Mothers With Phenylketonuria (PKU)

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Effects of Maternal Phenylketonuria (PKU) on Pregnancy Outcome

Brief Summary: Phenylketonuria (PKU) is a rare genetic condition. If not treated, PKU can cause severe mental retardation. Women with PKU are advised to eat a special diet when pregnant to prevent mental retardation in their children. This study will evaluate the effects of that diet on the children of mothers with PKU.

Detailed Summary:

PKU is an autosomal recessive trait caused by the absence of phenylalanine hydroxylase. Phenylalanine hydroxylase is an enzyme involved in the metabolism of phenylalanine (Phe). When phenylalanine hydroxylase is absent or defective, Phe levels rise and toxic Phe metabolites accumulate, causing central nervous system injury. PKU is a treatable disease. Affected individuals must adhere to a diet low in Phe during childhood. Women with PKU should also adhere to a low Phe diet before and during pregnancy to avoid fetal damage. The offspring of women with untreated maternal hyperphenylalaninemia (HPA) usually exhibit mental retardation, microcephaly, growth retardation, and other congenital anomalies. This study will examine the effect of a restricted Phe diet on reproductive outcome in women with maternal HPA.

Participants in this study will be women with HPA whose blood Phe values are persistently greater than 4 mg/dl. Those women with blood Phe values consistently greater than 8 mg/dl will be placed on a Phe restricted diet to maintain plasma Phe concentrations between 2 and 8 mg/dl. This level of control is practical and achievable. Due to a gradient of increasing Phe level from mother to fetus, levels in the latter would vary from 3.5 to 12 mg/dl; these levels are usually associated with normal outcomes. Women will be monitored throughout their pregnancy on obstetric, biochemical, and nutritional parameters. Women on the Phe restricted diet will be given enough Phe-limited protein, calories, vitamins, and minerals to maintain adequate nutritional status. Folate supplementation will be provided. If indicated clinically, tyrosine (Tyr) and supplemental trace metals will be prescribed.

A matching control sample of women and their offspring will be developed in collaboration with associated coordinating and collaborating cente
Sponsor: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

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Information By: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

Dates:
Date Received: July 21, 2003
Date Started: May 1984
Date Completion: April 2000
Last Updated: June 23, 2005
Last Verified: May 2000