Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (204 page)

   Rarely identified before puberty.

   May be mildly symptomatic; 3–7% prevalence in total population.

NEONATAL JAUNDICE: BREAST MILK JAUNDICE

   Due to the presence in mother’s milk of pregnanediol, which inhibits glucuronyl transferase activity

   Laboratory Findings

   Severe unconjugated hyperbilirubinemia. Develops in 1% of breast-fed infants by the 4th to 7th day. May reach peak of 15–25 mg/dL by the 2nd to 3rd week; then gradually disappears in 3–10 weeks in all cases. If nursing is interrupted, serum bilirubin falls rapidly by 2–6 mg/dL in 2–6 days and may rise again if breast-feeding is resumed; if interrupted for 6–9 days, serum bilirubin becomes normal.

   No other abnormalities are present.

   Kernicterus does not occur.

LUCEY-DRISCOLL SYNDROME (NEONATAL TRANSIENT FAMILIAL HYPERBILIRUBINEMIA)

   Syndrome is due to some factor in mother’s serum only during the last trimester of pregnancy that inhibits glucuronyl transferase activity; disappears about 2 weeks postpartum.

   Newborn infants have severe nonhemolytic unconjugated hyperbilirubinemia usually ≤20 mg/dL during the first 48 hours and a high risk of kernicterus.

WILSON DISEASE

   Autosomal recessive defect that impairs copper excretion by the liver, which may cause copper accumulation in the liver and brain resulting in cirrhosis, neuropsychiatric disease, and corneal pigmentation.

   Heterozygous gene for Wilson disease occurs in 1 of 200 in the general population; 10% of these have decreased serum ceruloplasmin; liver copper is not increased (<250 μg/g of dry liver). Serum copper and ceruloplasmin and urine copper are inadequate to detect heterozygous state.

   Homozygous gene (clinical Wilson disease) occurs in 1 of 200,000 in the general population.

   Liver biopsy may show no abnormalities, moderate to marked fatty changes with or without fibrosis, or active or inactive mixed micronodular–macronodular cirrhosis.