An Australian study has revealed that the country’s prevalence of vision loss due to Leber hereditary optic neuropathy (LHON) is at least one in 68,403. LHON is a mitochondrial disease that atrophies retinal ganglion cells and is inherited maternally.
Led by Dr Isabel Sanchez, from the Centre for Eye Research Australia in Melbourne, the study also identified 96 genetically unrelated LHON pedigrees – including 56 new ones – and updated 40 previously known pedigrees in Australia. However, three primary mutations accounted for 88.2% of all LHON cases.
Researchers noted that a single LHON mutation is not sufficient to cause vision loss but that gene interactions and risk factors such as smoking, heavy alcohol use and exposure to toxic drugs may be triggers for such carriers. Of the 96 Australian families that have the gene, it has caused vision loss in 355 individuals.
Researchers reported that their findings confirmed their previous report showing a generational fall in prevalence of vision loss among Australian men, however, LHON affected more males than females, in a ratio of almost 3:1, with vision loss experienced by 17.5% of male carriers and 5.4% of female carriers. They said they hope that the information will prove useful in family planning for families affected by LHON.