Evaluating neonatal hyperbilirubinemia in late preterm Hispanic twins led to the diagnosis of hereditary spherocytosis in them, and in their sibling and in their mother.

We identified four cases of hereditary spherocytosis (HS) in one Utah family, originally from Southwestern Mexico. The index cases were twin girls born at 35 weeks gestation, in whom the combination of hyperbilirubinemia, reticulocytosis and elevated mean corpuscular hemoglobin concentration (MCHC) led to studies that confirmed the diagnosis of HS. Scleral icterus in their 4-year-old sibling and in their mother led to the diagnosis of HS in them as well. Although much less commonly reported in Hispanic neonates than in those of Northern European ancestry, HS does occur among Hispanic neonates and can contribute to significant neonatal hyperbilirubinemia. These cases are consistent with our earlier report, which identified an MCHC cutoff of >36 as suggestive of further evaluation for HS.