Juvenile cobalamin deficiency in a 17-year-old child with autonomic dysfunction and skin changes.

We report a rare case of juvenile cobalamin deficiency who presented at the age of 17 years. He was underweight and had skin changes, normocytic anemia, and autonomic dysfunction, which led to adynamic ileus and acute postrenal failure. The expected macrocytosis was masked by an underlying alpha-thalassemia trait.

Ancient founder mutation is responsible for Imerslund-Gräsbeck Syndrome among diverse ethnicities.

Background: Imerslund-Gräsbeck syndrome (IGS) was described just over 50 years ago by Olga Imerslund and Ralph Gräsbeck and colleagues. IGS is caused by specific malabsorption of cobalamin (Cbl) due to bi-allelic mutations in either the cubilin gene (CUBN) or the human amnionless homolog (AMN). Mutations in the two genes are commonly seen in founder populations or in societies with a high degree of consanguineous marriages.