Korean J Pediatr.  2008 May;51(5):546-550. 10.3345/kjp.2008.51.5.546.

A case of two sisters births from mother with phenylketonuria lacking mental retardation

• Ki CS
• Kim JK

• KMID: 2280465
• DOI: http://doi.org/10.3345/kjp.2008.51.5.546

Abstract

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/-).

Keyword

Phenylalanine; Phenylalanine hydroxylase; Phenylketonuria; Maternal phenylketonuria syndrome

MeSH Terms

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
Phenylalanine
Phenylalanine Hydroxylase