Alterations in Metabolic Status Jan Bazner-Chandler RN, MSN, CNS, CPNP

Developmental and Biologic Variances Most inborn errors of metabolism present in the childhood years and, if untreated, results in early death. Cognitive defects and neurologic symptoms (lethargy, seizures, coma) Short stature and failure to thrive Feed problems and vomiting after feeding Delayed tooth eruption Hepatomegaly Urine may have abnormal odor and color

Metabolic Disorders Inborn errors of metabolism Maple syrup urine disease Mineral disorders Rickets Wilson disease Galactosemia

Neonatal Screening Over 30 inborn metabolic errors possible. PKU, glactosemia, maple syrup disease included in most newborn screening Newborns are not routinely tested for the rare disorders due to cost-to-benefit ratio.

Phenylketonuria PKU First discovered in 1934 PKU is an autosomal recessive genetic defect found on chromosome 12 Child must receive the defective gene from both parents 1 in 60 people is an asymptomatic carrier Symptoms 1 in 10,000 births In turkey 23 in 10,000

Pathophysiology Phenylalanine is an essential amino acid found in all protein food. The accumulation of phenylalanine leads to severe retardation. With early identification of the defective gene intervention can prevent retardation.

Diagnosis Heel stick done 24 to 48 hours after birth. Infant must have an adequate intake of breast milk or formula. (protein) The drop of blood must be large enough to fill the imprinted space on the filter paper. Squeezing out more blood onto the paper creates a layered effect that can produce a false-positive test result.

Treatment Focuses on preventing excessive accumulation of phenylalanine by restricting protein intake. Maintain levels below 0.9 mmol/L but maintain at0.2 to allow for normal growth and tissue repair. Aspartame or NutraSweet need to be avoided in diet.

Prognosis Teaching that reinforces the dietary regimen is critical to the successful management of PKU Family cohesion and adherence to the restricted diet positively correlates with higher IQ levels. Children at high risk for learning difficulties. Diet generally discontinued around 10 years with full brain development Pregnant women with PKU deficiency at high risk for having a fetus with mental retardation.