Spastic paraplegia type 2 (SPG2)
General description
Spastic paraplegia type 2 (SPG2) is an X-linked recessive inheritance caused by The Proteolipod protein (PLP) 1 gene. The PLP1 is associated with a membrane protein of the myelin sheath, and PLP1 gene-related central nervous system myelinopathies due to this abnormality range from Pelizaeus-Merzbacher Disease (PMD) to Spastic Paraplegia 2 (SPG2, this article). PMD has a poor prognosis due to severe myelodysplasia, but SPG2 has a relatively good prognosis for life, as it presents as spastic paraplegia but may not have central nervous system symptoms.
Clinical manifestations
Typical symptoms include motor developmental delay, spastic paraplegia, dysarthria, dysphagia, and ataxia. Symptoms typically remain consistent within families, though some variation exists among families. Female carriers may also experience mild to moderate symptoms.
White matter hyperintensity
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CerebrumCerebral white matterPeriventricular white matter
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CerebrumCerebral white matterDeep white matter
T2WI shows diffuse faint hyperintensity, mainly affecting the deep and periventricular white matter of the cerebrum, while the subcortical U-fibers are typically preserved.
Internal capsule lesion
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Internal capsulePosterior limb
T2WI reveals bilateral hyperintensity in the posterior limb of the internal capsule. DWI also shows hyperintensity, but there is no decrease in ADC.