A case of maternal PKU syndrome despite intensive patient counseling

Area of Science:

• Medical Genetics
• Metabolic Disorders
• Reproductive Medicine

Background:

• Phenylketonuria (PKU) is an inherited metabolic disorder requiring lifelong dietary management.
• Maternal PKU syndrome occurs when women with PKU have poorly controlled phenylalanine levels during pregnancy.
• Effective preconception counseling and management are crucial to prevent adverse fetal outcomes.

Observation:

• A 21-year-old woman with classic PKU presented at 14 weeks gestation with elevated blood phenylalanine (Phe) levels despite preconception counseling.
• Inpatient management temporarily normalized Phe levels, but the patient demonstrated non-compliance with dietary restrictions.
• The patient delivered a neonate exhibiting classic maternal PKU syndrome features, including microcephaly and developmental delays.

Findings:

• Despite intensive counseling, the patient's non-compliance with a Phe-restricted diet resulted in uncontrolled hyperphenylalaninemia during pregnancy.
• The offspring presented with severe congenital anomalies characteristic of untreated maternal PKU, a condition rarely seen with adherence to preconception dietary management.
• Patient compliance is a critical determinant in preventing fetal complications associated with maternal PKU.

Implications:

• This case underscores the critical importance of sustained patient adherence to phenylalanine restriction for successful pregnancy outcomes in women with PKU.
• Intensified preconception counseling and ongoing support are vital for women with PKU planning pregnancies.
• Strategies to improve long-term patient compliance in managing PKU during pregnancy are urgently needed to prevent severe embryopathy.