Methylmalonic aciduria, hyperhomocysteinemia, hematologic and/or neurologic abnormalities in 3 infants born to mothers with asymptomatic B₁₂ deficiency

Abstract

We describe three unrelated patients who were the offspring of mothers on unrestricted diets and presented with signs and symptoms consistent with either an acquired or inborn error of B₁₂ metabolism. All were solely breast-fed.

All three children showed good recovery after B₁₂ replacement, although mild hypotonia still persists in the 3^rd patient. These patients demonstrate that mothers without overt signs of pernicious anemia or B₁₂ deficiency can have children with B₁₂ deficiency with anemia and neurologic abnormalities. Acquired infant B₁₂ deficiency must be considered despite a maternal dietary history that includes animal proteins.