Heterozygous Mutations in Both the AMN and CBS Genes: Double Haploinsufficiency as an Unusual Cause of Vitamin B12 Deficiency—A Case Report

Abstract

ABSTRACT Vitamin B12 deficiency is usually simple to diagnose. However, our patient demonstrates that in difficult cases, the ordinary clinician may need a transdisciplinary approach. The finding of a double haploinsufficiency as a possible cause of vitamin B12 deficiency in our patient, illustrates the usefulness of performing large panel clinical exome sequencing.

Keywords

• folic acid
• general medicine
• hematology
• vitamin B12