Tokyo-1 Mutation: Hereditary Spherocytosis in a Hispanic Newborn Presenting as Early Onset Severe Hyperbilirubinemia.

BACKGROUND

Hereditary spherocytosis in the Hispanic population does not often present with severe hyperbilirubinemia. Spectrin and band 3 mutations are most frequent in this population.

CASE REPORT: We present a Hispanic full-term female newborn with early onset significant hyperbilirubinemia without a history of familial hemolytic disorders. She was diagnosed with hereditary spherocytosis based on laboratory findings, including presence of spherocytes on a peripheral smear, and was later found by next-generation sequencing to have Tokyo-1 mutation, an ANK1 gene mutation, that was previously only reported in Japanese population.

CONCLUSION

Our report adds to the currently limited literature of the genetic spectrum and characteristics of hereditary spherocytosis in the Hispanic population. The absence of a positive family history does not preclude hereditary spherocytosis as a differential for pathologic neonatal hyperbilirubinemia.