This study reports a boy with psychomotor retardation and epilepsy due to maternal phenylketonuria (PKU). The boy was admitted at the age of 20 months because of psychomotor retardation and epilepsy. He had seizures from the age of 1 year. His development quotient was 43. He presented with microcephaly, normal skin and hair color. Brain MRI scan showed mild cerebral white matter demyelination, broadening bilateral lateral ventricle and foramen magnum stricture. Chromosome karyotype, urine organic acids, blood amino acids and acylcarnitines were normal. His mother had mental retardation from her childhood. She presented with learning difficulties and yellow hair. Her premarriage health examinations were normal. She married a healthy man at age of 26 years. When she visited us at 28 years old, PKU was found by markedly elevated blood phenylalanine (916.54 μmol/L vs normal range 20-120 μmol/L). On her phenylalanine hydroxylase (PAH) gene, a homozygous mutations c.611A>G (p.Y204C) was identified, which confirmed the diagnosis of PAH-deficient PKU. Her child carries a heterozygous mutation c.611A>G with normal blood phenylalanine. Her husband had no any mutation on PAH. It is concluded that family investigation is very important for the etiological diagnosis of the children with mental retardation and epilepsy. Carefully clinical and metabolic survey should be performed for the parents with mental problems to identify parental diseases-associated child brain damage, such as maternal PKU.
Adult ; Epilepsy ; etiology ; Female ; Humans ; Infant ; Intellectual Disability ; etiology ; Male ; Phenylalanine Hydroxylase ; genetics ; Phenylketonuria, Maternal ; Pregnancy

In this untreated classic phenylketonuria (PKU) case, mental retardation is severe; however, there have been individuals-like the mother of this case who have escaped mental retardation and all the other potential sequelae of phenylketonuria, despite having high blood phenylalanine levels, and very poor dietary control. It appears that they have nearly normal brain phenylalanine levels despite high blood phenylalanine (Phe) levels. A number of studies have now demonstrated considerable variability in blood vs. brain phenylalanine levels in phenylketonuria patients. Outcome of phenylketonuria appears to be related to brain phenylalanine levels. We report a case of "undiagnosed" maternal phenylketonuria syndrome. A female infant had low birth weight (2,400 g) with microcephaly. We examined her family and discovered that her mother was an undiagnosed phenylketonuria patient with a borderline intelligence quotient (IQ). The infant's sister, six years old, was diagnosed with phenylketonuria at the age of four years was mentally retarded and had received an operation for cleft lip and palate. the sister had also had a low birth weight (2,300 g). Her sister and mother were compound heterozygotes (mother: R243Q/Y325X; sister: Y325X/P407S). The infant and father were heterozygous carriers (baby: R243Q/-; father: P407S/-).
Brain ; Cleft Lip ; Fathers ; Female ; Heterozygote ; Humans ; Infant ; Infant, Low Birth Weight ; Infant, Newborn ; Intellectual Disability ; Intelligence ; Mentally Disabled Persons ; Microcephaly ; Mothers ; Palate ; Parturition ; Phenylalanine ; Phenylalanine Hydroxylase ; Phenylketonuria, Maternal ; Phenylketonurias ; Siblings ; United Nations