RT Journal Article
SR Electronic
T1 Molecular diagnosis in mitochondrial complex I deficiency using exome sequencing
JF Journal of Medical Genetics
JO J Med Genet
FD BMJ Publishing Group Ltd
SP 277
OP 283
DO 10.1136/jmedgenet-2012-100846
VO 49
IS 4
A1 Tobias B Haack
A1 Birgit Haberberger
A1 Eva-Maria Frisch
A1 Thomas Wieland
A1 Arcangela Iuso
A1 Matteo Gorza
A1 Valentina Strecker
A1 Elisabeth Graf
A1 Johannes A Mayr
A1 Ulrike Herberg
A1 Julia B Hennermann
A1 Thomas Klopstock
A1 Klaus A Kuhn
A1 Uwe Ahting
A1 Wolfgang Sperl
A1 Ekkehard Wilichowski
A1 Georg F Hoffmann
A1 Marketa Tesarova
A1 Hana Hansikova
A1 Jiri Zeman
A1 Barbara Plecko
A1 Massimo Zeviani
A1 Ilka Wittig
A1 Tim M Strom
A1 Markus Schuelke
A1 Peter Freisinger
A1 Thomas Meitinger
A1 Holger Prokisch
YR 2012
UL http://jmg.bmj.com/content/49/4/277.abstract
AB Background Next generation sequencing has become the core technology for gene discovery in rare inherited disorders. However, the interpretation of the numerous sequence variants identified remains challenging. We assessed the application of exome sequencing for diagnostics in complex I deficiency, a disease with vast genetic heterogeneity.Methods Ten unrelated individuals with complex I deficiency were selected for exome sequencing and sequential bioinformatic filtering. Cellular rescue experiments were performed to verify pathogenicity of novel disease alleles.Results The first filter criterion was ‘Presence of known pathogenic complex I deficiency variants’. This revealed homozygous mutations in NDUFS3 and ACAD9 in two individuals. A second criterion was ‘Presence of two novel potentially pathogenic variants in a structural gene of complex I’, which discovered rare variants in NDUFS8 in two unrelated individuals and in NDUFB3 in a third. Expression of wild-type cDNA in mutant cell lines rescued complex I activity and assembly, thus providing a functional validation of their pathogenicity. Using the third criterion ‘Presence of two potentially pathogenic variants in a gene encoding a mitochondrial protein’, loss-of-function mutations in MTFMT were discovered in two patients. In three patients the molecular genetic correlate remained unclear and follow-up analysis is ongoing.Conclusion Appropriate in silico filtering of exome sequencing data, coupled with functional validation of new disease alleles, is effective in rapidly identifying disease-causative variants in known and new complex I associated disease genes.