Novel SLC25A32 mutation in a patient with a severe neuromuscular phenotype

Debby Mei Hellebrekers*, Suzanne C. E. H. Sallevelt, Tom E. J. Theunissen, Alexandra T. M. Hendrickx, Ralph W. Gottschalk, Janneke G. J. Hoeijmakers, Daphna D. Habets, Jorgen Bierau, Kees G. Schoonderwoerd, Hubert J. M. Smeets

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

17 Citations (Web of Science)

Abstract

In a 51-year-old patient of consanguineous parents with a severe neuromuscular phenotype of early-onset ataxia, myoclonia, dysarthria, muscle weakness and exercise intolerance, exome sequencing revealed a novel homozygous variant (c.-264-31delinsCTCACAAATGCTCA) in the mitochondrial FAD-transporter gene SLC25A32. Flavin adenine dinucleotide (FAD) is an essential co-factor for many mitochondrial enzymes and impaired mitochondrial FAD-transport was supported by a reduced oxidative phosphorylation complex II activity in the patient's muscle, decreased ATP production in fibroblasts, and a deficiency of mitochondrial FAD-dependent enzymes. Clinically, the patient showed improvement upon riboflavin treatment, which is a precursor of FAD. Our results confirm the recently reported case of SLC25A32 as a cause of riboflavin-responsive disease. Our patient showed a more severe clinical phenotype compared with the reported patient, corresponding with the (most likely) complete absence of the SLC25A32-encoding MFT (Mitochondrial Folate Transporter) protein.

Original languageEnglish
Pages (from-to)886-888
Number of pages3
JournalEuropean Journal of Human Genetics
Volume25
Issue number7
DOIs
Publication statusPublished - Jun 2017

Keywords

  • MITOCHONDRIAL
  • IDENTIFICATION
  • TRANSPORTER
  • RIBOFLAVIN

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