Report of rapid diagnosis and precise management of MMADHC- related intracellular cobalamin defect

BMJ Case Rep. 2021 Jun 3;14(6):e239755. doi: 10.1136/bcr-2020-239755.

Abstract

Disorders of intracellular cobalamin metabolism are a group of metabolic disorders that lead to varied clinical presentation from intrauterine life to adulthood. We report a male infant with developmental regression, macrocytic anaemia and hyperpigmentation. Exome sequencing identified a homozygous pathogenic variant in the MMADHC gene, known to cause homocystinuria, cblD type (MIM #277410). We describe significant clinical improvement with targeted therapy and emphasise the relevance of genomic testing in accurate management of inherited metabolic disorders.

Keywords: genetic screening / counselling; genetics; vitamins and supplements.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Homocystinuria* / complications
  • Homocystinuria* / diagnosis
  • Homocystinuria* / genetics
  • Humans
  • Infant
  • Intracellular Signaling Peptides and Proteins
  • Male
  • Mutation
  • Transcription Factors
  • Vitamin B 12 / therapeutic use
  • Vitamin B 12 Deficiency*

Substances

  • Intracellular Signaling Peptides and Proteins
  • MMADHC protein, human
  • Transcription Factors
  • Vitamin B 12