Spastic Paraplegia 2

Clinical Characteristics
Ocular Features: 

Nystagmus is common but variable in age of onset, and half of affected individuals have optic atrophy.

Systemic Features: 

This is a complex form of spastic paraplegia in which primarily lower limb spasticity is associated with dysarthria, sensory disturbances, cognitive deficits, muscle wasting and mild ataxia.  There is, however, considerable variability in age of onset and rate of symptom progression.  The first motor symptoms are often evident when children start walking, which is often delayed and clumsy.  However, evidence of spasticity may be present in children under 1 year of age.   Some patients have normal mental functions while others are considered mentally retarded.  The MRI reveals patchy leukodystrophy and degeneration of both corticospinal and spinocerebellar tracks was found in an autopsied individual.  Progression is relentless with many individuals requiring assistive devices such as crutches or walkers by early adult life.

Genetics

This is an X-linked disorder secondary to a mutation in the PLP1 gene at Xq22.2which codes for 2 major proteins found in myelin.  SPG2 is allelic to the more severe Pelizaeus-Merzbacher disease (312080).

Treatment
Treatment Options: 

Mobility devices and physical therapy can be helpful, especially in younger individuals.

References
Article Title: 

References

Inoue K. PLP1-related inherited dysmyelinating disorders: Pelizaeus-Merzbacher disease and spastic paraplegia type 2. Neurogenetics. 2005 Feb;6(1):1-16. Review.

PubMedID: 15627202

Goldblatt J, Ballo R, Sachs B, Moosa A. X-linked spastic paraplegia: evidence for homogeneity with a variable phenotype. Clin Genet. 1989 Feb;35(2):116-20.

PubMedID: 2470540