Leber's disease with G3635A mutation

February 1, 2014

In this article, the authors report on a case of two brothers with genetically proved Leber's disease associated with the rarer mutation G3635A, which is the only family case encountered in Bulgaria thus far.

The prevalence of Leber's disease is estimated at around 1/15000–1/50000 people. The clinical manifestation is acute or subacute, painless loss of central vision, which is usually persistant (with varying chance for recovery of vision depending on the mutation).

The most frequently found mutations in European patients are in the 3460, 11778 and 14484 nucleotides (associated with 90% of the cases). However, there are some other primary mutations, as well as secondary mutations that mostly affect the penetrance of the disease, which is incomplete in the LHON families - only 50% of men and 10% of women with the typical mtDNA mutations develop optic neuropathy.^1–4

OCT: Valuable assessment

Some studies in LOHN have found that the fibres in the nasal quadrant show the lowest reduction, while the first and the most severely affected ones are the temporal segments, and that RNFL is thickened during the early stages of the optic neuropathy (duration of less than 6 months), while it shows thinning in the later, atrophic stages (more than 6 months).⁷