Whole mitochondrial genome screening in maternally inherited non-syndromic hearing impairment using a microarray resequencing mitochondrial DNA chip.
Mitochondrial DNA (mtDNA) mutations have been implicated in non-syndromic hearing loss either as primary or as predisposing factors. As only a part of the mitochondrial genome is usually explored in deafness, its prevalence is probably under-estimated. Among 1350 families with non-syndromic sensorineural hearing loss collected through a French collaborative network, we selected 29 large families with a clear maternal lineage and screened them for known mtDNA mutations in 12S rRNA, tRNASer(UCN) and tRNALeu(UUR) genes. When no mutation could be identified, a whole mitochondrial genome screening was performed, using a microarray resequencing chip: the MitoChip version 2.0 developed by Affymetrix Inc. Known mtDNA mutations was found in nine of the 29 families, which are described in the article: five with A1555G, two with the T7511C, one with 7472insC and one with A3243G mutation. In the remaining 20 families, the resequencing Mitochip detected 258 mitochondrial homoplasmic variants and 107 potentially heteroplasmic variants. Controls were made by direct sequencing on selected fragments and showed a high sensibility of the MitoChip but a low specificity, especially for heteroplasmic variations. An original analysis on the basis of species conservation, frequency and phylogenetic investigation was performed to select the more probably pathogenic variants. The entire genome analysis allowed us to identify five additional families with a putatively pathogenic mitochondrial variant: T669C, C1537T, G8078A, G12236A and G15077A. These results indicate that the new MitoChip platform is a rapid and valuable tool for identification of new mtDNA mutations in deafness.
Lévêque
Marianne
M
INSERM U587, Pasteur Institute, Paris, France. marilvq@aol.com
Marlin
Sandrine
S
Jonard
Laurence
L
Procaccio
Vincent
V
Reynier
Pascal
P
Amati-Bonneau
Patrizia
P
Baulande
Sylvain
S
Pierron
Denis
D
Lacombe
Didier
D
Duriez
Françoise
F
Francannet
Christine
C
Mom
Thierry
T
Journel
Hubert
H
Catros
Hélène
H
Drouin-Garraud
Valérie
V
Obstoy
Marie-Françoise
MF
Dollfus
Hélène
H
Eliot
Marie-Madeleine
MM
Faivre
Laurence
L
Duvillard
Christian
C
Couderc
Remy
R
Garabedian
Eréa-Noël
EN
Petit
Christine
C
Feldmann
Delphine
D
Denoyelle
Françoise
F
D000328:Adult; D000818:Animals; D002417:Cattle; D002648:Child; D004272:DNA, Mitochondrial / Q000235:genetics*; D004285:Dogs; D015180:Electrophoresis, Gel, Two-Dimensional / Q000295:instrumentation / Q000379:methods; D005260:Female; D054629:Genome, Mitochondrial; D006319:Hearing Loss, Sensorineural / Q000235:genetics*; D006801:Humans; D008297:Male; D051379:Mice; D008928:Mitochondria / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation / Q000379:methods*; D010375:Pedigree; D017354:Point Mutation; D051381:Rats; D017422:Sequence Analysis, DNA / Q000295:instrumentation / Q000379:methods*
D004272:DNA, Mitochondrial