Spastic Paraplegia, Optic Atrophy, and Neuropathy

Clinical Characteristics

Ocular Features:

Non-progressive optic atrophy with vision loss is described as congenital in onset.

Systemic Features:

Progressive spasticity has its onset in infancy with loss of independent mobility usually in the second decade of life. An exaggerated startle response occurs in some individuals. All patients are confined to wheelchairs after 15 years of age due to progressive motor neuropathy. No intellectual disability has been reported. Joint contractures occur. Dysarthria is notable in the third decade of life. Eventually joint contractures and spine deformities occur.

Genetics

Homozygous mutations in the KLC2 gene (11q13.2) have been found in this disorder. A homozygous 216-bp deletion in a non-coding region upstream of the gene results in overexpression of the gene not found in heterozygotes.

Treatment

Treatment Options:

No treatment has been described.

References

Article Title:

Overexpression of KLC2 due to a homozygous deletion in the non-coding region causes SPOAN syndrome

Melo US, Macedo-Souza LI, Figueiredo T, Muotri AR, Gleeson JG, Coux G, Armas P, Calcaterra NB, Kitajima JP, Amorim S, Olavio TR, Griesi-Oliveira K, Coatti GC, Rocha CR, Martins-Pinheiro M, Menck CF, Zaki MS, Kok F, Zatz M, Santos S. Overexpression of KLC2 due to a homozygous deletion in the non-coding region causes SPOAN syndrome. Hum Mol Genet. 2015 Dec 15;24(24):6877-85.

PubMed ID:

26385635