Optic Atrophy 5

Clinical Characteristics
Ocular Features: 

The phenotype in OPA5 has some similarities to that of OPA1 (125250, 165500).  Onset occurs as early as the first decade of life in some families but may not be evident until the third decade in other families.  Visual acuity decreases slowly and color vision is impaired, more so in older patients.  Temporal pallor of the optic nerve is usually present and central scotomas with narrowing of the visual fields can be plotted.  The nerve fiber layer is reduced in thickness.  VEP defects likewise are variable and generally more severe in later stages.  No ERG abnormalities have been reported.  This is a bilateral disease with nearly 100% penetrance.

Systemic Features: 

No systemic abnormalities are present.

Genetics

Heterozygous mutations in the DNM1L gene (12p11.21) are found in patients with OPA5.  Morphologic changes found in mitochondria have been interpreted as consistent with an impairment in fission.  Two families who had been previously reported to have mutations at the 22q12.1 locus were found to have the DNM1L mutation.

Like several other forms of heritable optic atrophy, OPA1 (125250, 165500) and OPA4 (605293), this is an autosomal dominant disorder.  

Treatment
Treatment Options: 

No treatment of the optic atrophy is available but low vision aids can be helpful to utilize remaining vision.

References
Article Title: 

Mutations in DNM1L, as in OPA1, result in dominant optic atrophy despite opposite effects on mitochondrial fusion and fission

Gerber S, Charif M, Chevrollier A, Chaumette T, Angebault C, Kane MS, Paris A, Alban J, Quiles M, Delettre C, Bonneau D, Procaccio V, Amati-Bonneau P, Reynier P, Leruez S, Calmon R, Boddaert N, Funalot B, Rio M, Bouccara D, Meunier I, Sesaki H, Kaplan J, Hamel CP, Rozet JM, Lenaers G. Mutations in DNM1L, as in OPA1, result in dominant optic atrophy despite opposite effects on mitochondrial fusion and fission. Brain. 2017 Oct 1;140(10):2586-2596.

PubMed ID: 
28969390

References

Gerber S, Charif M, Chevrollier A, Chaumette T, Angebault C, Kane MS, Paris A, Alban J, Quiles M, Delettre C, Bonneau D, Procaccio V, Amati-Bonneau P, Reynier P, Leruez S, Calmon R, Boddaert N, Funalot B, Rio M, Bouccara D, Meunier I, Sesaki H, Kaplan J, Hamel CP, Rozet JM, Lenaers G. Mutations in DNM1L, as in OPA1, result in dominant optic atrophy despite opposite effects on mitochondrial fusion and fission. Brain. 2017 Oct 1;140(10):2586-2596.

PubMedID: 28969390

Barbet F, Hakiki S, Orssaud C, Gerber S, Perrault I, Hanein S, Ducroq D, Dufier JL, Munnich A, Kaplan J, Rozet JM. A third locus for dominant optic atrophy on chromosome 22q. J Med Genet. 2005 Jan;42(1):e1.

PubMedID: 15635063