2. Academic Validation
  3. Mutations in ABCD4 cause a new inborn error of vitamin B12 metabolism

Mutations in ABCD4 cause a new inborn error of vitamin B12 metabolism

  • Nat Genet. 2012 Oct;44(10):1152-5. doi: 10.1038/ng.2386.
David Coelho 1,  Jaeseung C Kim,  Isabelle R Miousse,  Stephen Fung,  Marcel du Moulin,  Insa Buers,  Terttu Suormala,  Patricie Burda,  Michele Frapolli,  Martin Stucki,  Peter Nürnberg,  Holger Thiele,  Horst Robenek,  Wolfgang Höhne,  Nicola Longo,  Marzia Pasquali,  Eugen Mengel,  David Watkins,  Eric A Shoubridge,  Jacek Majewski,  David S Rosenblatt,  Brian Fowler,  Frank Rutsch,  Matthias R Baumgartner
Affiliations

Affiliation

  • 1 Division of Metabolism, Children's Research Center (CRC), University Children's Hospital, Zürich, Switzerland.
PMID: 22922874 DOI: 10.1038/ng.2386
Abstract

Inherited disorders of vitamin B12 (cobalamin) have provided important clues to how this vitamin, which is essential for hematological and neurological function, is transported and metabolized. We describe a new disease that results in failure to release vitamin B12 from lysosomes, which mimics the cblF defect caused by LMBRD1 mutations. Using microcell-mediated chromosome transfer and exome Sequencing, we identified causal mutations in ABCD4, a gene that codes for an ABC transporter, which was previously thought to have peroxisomal localization and function. Our results show that ABCD4 colocalizes with the lysosomal proteins LAMP1 and LMBD1, the latter of which is deficient in the cblF defect. Furthermore, we show that mutations altering the putative ATPase domain of ABCD4 affect its function, suggesting that the ATPase activity of ABCD4 may be involved in intracellular processing of vitamin B12.

Figures