neonatology microcephaly caused by maternal hyperphenylalaninemia

Maternal hyperphenylalaninemia, most commonly due to phenylketonuria (PKU), can have severe teratogenic effects on the developing fetus if not properly managed. Approximately ۱% of patients with PKU may remain clinically asymptomatic even without treatment. this individuals usually have milder forms of the disease, with relatively low levels of phenylalanine in their blood and no severe neurologic damage. One of the most significant neurological outcomes is microcephaly, a condition characterized by an abnormally small head and brain size, often associated with intellectual disability and developmental delay. Phenylketonuria is an autosomal recessive disorder resulting from a deficiency of the enzyme phenylalanine hydroxylase, leading to the accumulation of phenylalanine (Phe) in the blood. While dietary management allows individuals with PKU to lead relatively normal lives, elevated maternal phenylalanine levels during pregnancy can cross the placenta and affect fetal development, even if the fetus does not have PKU. Microcephaly in infants born to mothers with uncontrolled hyperphenylalaninemia is believed to result from the toxic effects of high phenylalanine on brain development. Phenylalanine competes with other large neutral amino acids for transport across the blood-brain barrier, disrupting normal protein synthesis and neurotransmitter production. This disruption is especially harmful during early gestation when the brain is rapidly developing. The severity of microcephaly and other complications, such as congenital heart defects, intrauterine growth restriction, and intellectual disability, is directly related to the level of maternal phenylalanine during pregnancy. Studies have shown that maintaining maternal blood phenylalanine levels between ۱۲۰-۳۶۰ μmol/L significantly reduces the risk of microcephaly and other fetal abnormalities. To prevent such outcomes, it is essential that women with PKU follow a strict low-phenylalanine diet before conception and throughout pregnancy. Early diagnosis, regular monitoring, and dietary compliance are crucial for optimal maternal and fetal health. We want to introduce a patient resulting from uncontrolled maternal phenylketonuria.