Ladies with Leber's hereditary optic neuropathy: an atypical disease.

PURPOSE: Leber's Hereditary Optic Neuropathy (LHON) is considered to be a disease predominantly affecting young males. The risk of women becoming symptomatic if they are carriers of a primary mutation is 1/5 of that in males. The disease however appears to behave differently in women in some instances. We describe three cases of ladies with LHON and discuss the importance of making the diagnosis. CASE REPORTS: A 28-year-old female presented with blurring of vision in her left eye with bilateral small hyperemic discs and telangiectatic vessels adjacent to them. DNA analysis confirmed the 11778 mutation and the second eye remains unaffected 10 years later. The second case was 49 years old and presented with bilateral visual loss developing over 3 months. She had no family history of visual loss but had a past history of Wolf Parkinson White syndrome and 3460 mutation was confirmed. The last case was diagnosed with multiple sclerosis at age 24 and went on to develop visual loss with poor recovery. DNA analysis demonstrated the 11778 mutation and confirmed LHON.
CONCLUSIONS: All three cases, although not unique, posed considerable diagnostic difficulties over a long period of time. The authors have highlighted important associations of the disease and stress the importance of making the diagnosis in women. They are at increased risk of having affected children, unlike the affected males, especially if they are affected themselves and may wish to seek further genetic advice.