HSP 31 #HSP31 #SPG31

Spastic Paraplegia 31 (SPG31) Overview:

- Definition: Rare genetic disorder causing progressive leg weakness/spasticity

- Cause: REEP1 gene mutations

- Inheritance: Autosomal dominant

- Symptoms:

1. Leg spasticity/stiffness

2. Weakness or paralysis in legs

3. Difficulty walking/balance issues

4. Urinary urgency/incontinence

5. Constipation

- Onset: Childhood/adolescence

- Progression: Slowly progressive over decades

- Diagnosis: Genetic testing/neurological exams

SPG31 Genetics:

- Cause: Mutations in the REEP1 gene

- Location: Chromosome 2p11.2

- Function: REEP1 helps build and maintain endoplasmic reticulum structure in neurons

- Mutation types:

1. Missense mutations (changing amino acid)

2. Nonsense mutations (premature stop codon)

3. Frameshift mutations (deleting/inserting nucleotides)

- Inheritance:

- Autosomal dominant: 1 copy of mutated gene causes SPG31

- Penetrance: High (most carriers develop symptoms)

- Expressivity: Variable (symptom severity differs among carriers)