Optic Atrophy 3 and Cataracts

Clinical Characteristics
Ocular Features: 

There is considerable variation in age of onset and severity of clinical disease.  Cataracts may be evident in the first decade of life but in most cases by the second decade.  They are usually described as anterior or posterior cortical opacities.  Progression of opacification is slow and most patients do not require removal until late adulthood and some never require surgery. Visual impairment from optic atrophy may be evident in infancy and some patients experience a worsening in late adulthood.  Visual acuity is highly variable.  Temporal pallor may be present in childhood or later.

Systemic Features: 

Neurologic signs such as tremor, extrapyramidal rigidity in the upper extremities, and ataxia are seldom present until after the age of 50 years.  However not all patients have neurologic disease.

Genetics

This disorder is inherited in an autosomal dominant pattern as a result of a mutation in the OP3 gene (19q13.2-q13.3) encoding an inner membrane mitochondrial protein.  It is allelic to autosomal recessive optic atrophy-3, or 3-methylglutaconic aciduria type III (258501), sometimes called Behr early onset optic atrophy (210000). 

Optic atrophy 3 is less severe than in Behr optic atrophy and the presence of cataracts is an important distinguishing feature.  For these reasons, optic atrophy 3 is discussed as a separate disorder here.   However, the nosology remains unclear since not all individuals with Behr optic atrophy have 3-methylglutaric acidemia.  

Treatment
Treatment Options: 

No effective treatment is available for the optic atrophy.  Cataract surgery may be necessary for visually significant lens opacities.

References
Article Title: 

OPA3 gene mutations responsible for autosomal dominant optic atrophy and cataract

Reynier P, Amati-Bonneau P, Verny C, Olichon A, Simard G, Guichet A, Bonnemains C, Malecaze F, Malinge MC, Pelletier JB, Calvas P, Dollfus H, Belenguer P, Malthi?(r)ry Y, Lenaers G, Bonneau D. OPA3 gene mutations responsible for autosomal dominant optic atrophy and cataract. J Med Genet. 2004 Sep;41(9):e110.

PubMed ID: 
15342707

[On a heredo-familial disease combining cataract, optic atrophy, extrapyramidal symptoms and certain defects of Friedreich's disease]

GARCIN R, RAVERDY P, DELTHIL S, MAN HX, CHIMENES H. [On a heredo-familial disease combining cataract, optic atrophy, extrapyramidal symptoms and certain defects of Friedreich's disease. (Its nosological position in relation to the Behr's syndrome, the Marinesco-Sjogren syndrome and Friedreich's disease with ocular symptoms.]. Rev Neurol (Paris). 1961 May;104:373-9. French.

PubMed ID: 
13703570

References

Reynier P, Amati-Bonneau P, Verny C, Olichon A, Simard G, Guichet A, Bonnemains C, Malecaze F, Malinge MC, Pelletier JB, Calvas P, Dollfus H, Belenguer P, Malthi?(r)ry Y, Lenaers G, Bonneau D. OPA3 gene mutations responsible for autosomal dominant optic atrophy and cataract. J Med Genet. 2004 Sep;41(9):e110.

PubMedID: 15342707

GARCIN R, RAVERDY P, DELTHIL S, MAN HX, CHIMENES H. [On a heredo-familial disease combining cataract, optic atrophy, extrapyramidal symptoms and certain defects of Friedreich's disease. (Its nosological position in relation to the Behr's syndrome, the Marinesco-Sjogren syndrome and Friedreich's disease with ocular symptoms.]. Rev Neurol (Paris). 1961 May;104:373-9. French.

PubMedID: 13703570