OPA1-related dominant optic atrophy is not strongly influenced by mitochondrial DNA background.
BACKGROUND
Leber's hereditary optic neuropathy (LHON) and autosomal dominant optic atrophy (ADOA) are the most frequent forms of hereditary optic neuropathies. LHON is associated with mitochondrial DNA (mtDNA) mutations whereas ADOA is mainly due to mutations in the OPA1 gene that encodes a mitochondrial protein involved in the mitochondrial inner membrane remodeling. A striking influence of mtDNA haplogroup J on LHON expression has been demonstrated and it has been recently suggested that this haplogroup could also influence ADOA expression. In this study, we have tested the influence of mtDNA backgrounds on OPA1 mutations.


METHODS
To define the relationships between OPA1 mutations and mtDNA backgrounds, we determined the haplogroup affiliation of 41 French patients affected by OPA1-related ADOA by control-region sequencing and RFLP survey of their mtDNAs.


RESULTS
The comparison between patient and reference populations did not revealed any significant difference.


CONCLUSIONS
Our results argue against a strong influence of mtDNA background on ADOA expression. These data allow to conclude that OPA1 could be considered as a "severe mutation", directly responsible of the optic atrophy, whereas OPA1-negative ADOA and LHON mutations need an external factor(s) to express the pathology (i.e. synergistic interaction with mitochondrial background).
Pierron
Denis
D
Université Bordeaux 1, Laboratoire d'Anthropologie des Populations du Passé, UMR 5199 PACEA, 33400 Talence, France. d.pierron@anthropologie.u-bordeaux1.fr
Ferré
Marc
M
Rocher
Christophe
C
Chevrollier
Arnaud
A
Murail
Pascal
P
Thoraval
Didier
D
Amati-Bonneau
Patrizia
P
Reynier
Pascal
P
Letellier
Thierry
T
D015331:Cohort Studies; D004272:DNA, Mitochondrial / Q000235:genetics*; D005602:France; D020558:GTP Phosphohydrolases / Q000235:genetics*; D006239:Haplotypes; D006579:Heterozygote; D006801:Humans; D009154:Mutation; D029241:Optic Atrophy, Autosomal Dominant / Q000235:genetics*; D029242:Optic Atrophy, Hereditary, Leber / Q000235:genetics; D012150:Polymorphism, Restriction Fragment Length
D004272:DNA, Mitochondrial; D020558:GTP Phosphohydrolases; C415198:OPA1 protein, human