Spastic paraplegia 17

Alternate names

SPG17; Spastic paraplegia with amyotrophy of hands and feet; Silver syndrome; Silver spastic paraplegia syndrome; Autosomal dominant spastic paraplegia type 17

Definition

A complex hereditary spastic paraplegia characterized by progressive spastic paraplegia, upper and lower limb muscle atrophy, hyperreflexia, extensor plantar responses, pes cavus and occasionally impaired vibration sense. Association with hand muscles amyotrophy typical.

Epidemiology

Although Silver syndrome appears to be a rare condition, its exact prevalence is unknown.

Cause

Mutations in the BSCL2 gene cause Silver syndrome. The BSCL2 gene provides instructions for making a protein called seipin, whose function is unknown.

Inheritance

Autosomal dominant pattern, a 50/50 chance.

BSCL2-related neurologic disorders are inherited in an autosomal dominant manner.<ref>Ito D. BSCL2-Related Neurologic Disorders/Seipinopathy. 2005 Dec 6 [Updated 2018 May 24]. In: Adam MP, Ardinger HH, Pagon RA, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2021. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1307/</ref>

Signs and symptoms

• These disorders are characterized by progressive muscle stiffness (spasticity) and, frequently, development of paralysis of the lower limbs (paraplegia).
• Hereditary spastic paraplegias are divided into two types: pure and complex.
• Both types involve the lower limbs; the complex types may also involve the upper limbs, although to a lesser degree.
• In addition, the complex types may affect the brain and parts of the nervous system involved in muscle movement and sensations.
• Silver syndrome is a complex hereditary spastic paraplegia.
• The first sign of Silver syndrome is usually weakness in the muscles of the hands.
• These muscles waste away (amyotrophy), resulting in abnormal positioning of the thumbs and difficulty using the fingers and hands for tasks such as handwriting.
• People with Silver syndrome often have high-arched feet (pes cavus) and spasticity in the legs.
• The signs and symptoms of Silver syndrome typically begin in late childhood but can start anytime from early childhood to late adulthood.
• The muscle problems associated with Silver syndrome slowly worsen with age, but affected individuals can remain active throughout life.

Diagnosis

The diagnosis of a BSCL2-related neurologic disorder is established in a proband with characteristic clinical and electrophysiologic features and identification of a heterozygous BSCL2 pathogenic variant on molecular genetic testing.<ref>Ito D. BSCL2-Related Neurologic Disorders/Seipinopathy. 2005 Dec 6 [Updated 2018 May 24]. In: Adam MP, Ardinger HH, Pagon RA, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2021. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1307/</ref>[1].

Treatment

• Symptomatic treatment includes physiotherapy, orthopedic shoes, and calipers to stabilize gait.
• Foot deformities may be corrected with surgery.<ref>Ito D. BSCL2-Related Neurologic Disorders/Seipinopathy. 2005 Dec 6 [Updated 2018 May 24]. In: Adam MP, Ardinger HH, Pagon RA, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2021. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1307/</ref>

References

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NIH genetic and rare disease info

• NIH info on Spastic paraplegia 17

Spastic paraplegia 17 is a rare disease.