Mitochondrial encephalomyopathy due to a novel mutation in ACAD9

Caterina Garone, Maria Alice Donati, Michele Sacchini, Beatriz Garcia-Diaz, Claudio Bruno, Sarah Calvo, Vamsi K. Mootha, Salvatore DiMauro

Research output: Contribution to journalArticlepeer-review


IMPORTANCE: Mendelian forms of complex I deficiency are usually associated with fatal infantile encephalomyopathy. Application of "MitoExome" sequencing (deep sequencing of the entire mitochondrial genome and the coding exons of >1000 nuclear genes encoding the mitochondrial proteome) allowed us to reveal an unusual clinical variant of complex I deficiency due to a novel homozygous mutation in ACAD9. The patient had an infantile-onset but slowly progressive encephalomyopathy and responded favorably to riboflavin therapy. OBSERVATION: A 13-year-old boy had exercise intolerance, weakness, and mild psychomotor delay. Muscle histochemistry showed mitochondrial proliferation, and biochemical analysis revealed severe complex I deficiency (15% of normal). The level of complex I holoprotein was reduced as determined by use of Western blot both in muscle (54%) and in fibroblasts (57%). CONCLUSIONS AND RELEVANCE: The clinical presentation of complex I deficiency due ACAD9 mutations spans from fatal infantile encephalocardiomyopathy to mild encephalomyopathy. Our data support the notion that ACAD9 functions as a complex I assembly protein. ACAD9 is a flavin adenine dinucleotide-containing flavoprotein, and treatment with riboflavin is advisable.

Original languageEnglish
Pages (from-to)1177-1179
Number of pages3
JournalJAMA Neurology
Issue number9
Publication statusPublished - 2013

ASJC Scopus subject areas

  • Clinical Neurology


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