Spastic Paraplegia 15

Clinical Characteristics
Ocular Features: 

Yellowish flecks resembling those seen in fundus flavimaculatus are present, primarily in the macular area.   These can be present in large numbers in homozygotes with the full neurological syndrome.  Background retinal pigmentation appears clinically normal but fluorescein angiography shows a strikingly mottled picture with areas of hyper- and hypofluorescence.  Retinal flecks have also been reported in heterozygous parents.

The central macula exhibits autofluorescence.  Standard EOG and ERG recordings are normal but multifocal electroretinography shows subnormal responses in the macular area.  Visual acuity is minimally impacted.

Systemic Features: 

This is a form of spastic paraplegia with progressive spasticity primarily affecting the lower limbs.  Mental retardation (or at least cognitive impairment), dysarthria, a thin corpus callosum, and distal amyotrophy are often present.  Hearing deficits have also been described.  Some but not all patients have tremors, cerebellar ataxia, epilepsy and behavioral disturbances. Onset is between 10 and 19 years of age.  Little is known about the rate of symptom progression.

Genetics

This is an autosomal recessive disorder resulting from mutations in the ZFYVE26 gene (14q24.1).

Spastic paraplegia 7 (607259) has similar neurological features but with ptosis, optic atrophy, and nystagmus.  Congenital cataracts occur in addition to the neurological signs in spastic paraplegia 46 (614409) .

Other disorders with retinal flecks are described in Flecked Retina Syndromes.

Treatment
Treatment Options: 

No treatment is known.

References
Article Title: 

Fleck retina in Kjellin's syndrome

Farmer SG, Longstreth WT Jr, Kalina RE, Todorov AB. Fleck retina in Kjellin's syndrome. Am J Ophthalmol. 1985 Jan 15;99(1):45-50.

PubMed ID: 
3966518

References

Elleuch N, Bouslam N, Hanein S, Lossos A, Hamri A, Klebe S, Meiner V, Birouk N, Lerer I, Grid D, Bacq D, Tazir M, Zelenika D, Argov Z, Durr A, Yahyaoui M, Benomar A, Brice A, Stevanin G. Refinement of the SPG15 candidate interval and phenotypic heterogeneity in three large Arab families. Neurogenetics. 2007 Nov;8(4):307-15.

PubMedID: 17661097

Frisch IB, Haag P, Steffen H, Weber BH, Holz FG. Kjellin's syndrome: fundus autofluorescence, angiographic, and electrophysiologic findings. Ophthalmology. 2002 Aug;109(8):1484-91.

PubMedID: 12153800

Farmer SG, Longstreth WT Jr, Kalina RE, Todorov AB. Fleck retina in Kjellin's syndrome. Am J Ophthalmol. 1985 Jan 15;99(1):45-50.

PubMedID: 3966518