CONGENITAL PERNICIOUS ANEMIA: EFFECTS ON GROWTH, BRAIN, AND ABSORPTION OF B₁₂

Abstract

Three Irish children, two of them siblings, developed megaloblastic anemia around one year; deficiency of intrinsic factor (I.F.), presumably congenital, was shown by Schilling tests and assay of gastric juice. Congenital pernicious anemia (P.A.), in contrast to adult P.A., shows normal gastric mucosa and acidity and no antibodies to gastric mucosa or I.F. Adult type P.A., with gastric atrophy and achlorhydria, if occurring in childhood, can be called "juvenile P.A.," "congenital P.A." being reserved for the type described here. P.A. associated with polyendocrinopathy and the type described by Imerslund due to specific B₁₂ malabsorption should be named accordingly. Congenital P.A.'s inheritance is thought to be autosomal recessive.

Growth retardation and acceleration appeared to be related to B₁₂ deficiency and treatment. I.Q.'s of around 70 in each child may represent the effects of B₁₂ deficiency on cerebral growth. An initial malabsorption of B₁₂ was shown to improve markedly with B₁₂ treatment. In diagnosis of megaloblastic anemia, only that due to B₁₂ deficiency will respond to dosage of 2 to 5 µg B₁₂ (intramuscular) daily. Early diagnosis and treatment may prevent brain damage.