hereditary spastic paraplegia 26
Findings
No curated finding names hereditary spastic paraplegia 26 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A rare, complex type of hereditary spastic paraplegia characterized by the onset in childhood/adolescence (ages 2-19) of progressive spastic paraplegia associated mainly with mild to moderate cognitive impairment and developmental delay, cerebellar ataxia, dysarthria, and peripheral neuropathy. Less commonly reported manifestations include skeletal abnormalities (i.e. pes cavus, scoliosis), dyskinesia, dystonia, cataracts, cerebellar signs (i.e. saccadic dysfunction, nystagmus, dysmetria), bladder disturbances, and behavioral problems. SPG26 is caused by mutations in the B4GALNT1 gene (12q13.3), encoding Beta-1, 4 N-acetylgalactosaminyltransferase 1.
Definition from the Mondo Disease Ontology (MONDO:0012213), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Infantile onset · Progressive · Childhood onset · Early young adult onset
HPO, annotations 2026-09-02
Features
35 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Lower limb spasticityHPOHP:0002061
- 18 of 18 reported patients
- Frequent (30% to 79% of cases)
- Mild intellectual disabilityHPOHP:0001256
- 18 of 18 reported patients
- Babinski signHPOHP:0003487
- 14 of 15 reported patients
- Frequent (30% to 79% of cases)
- Lower limb muscle weaknessHPOHP:0007340
- 14 of 15 reported patients
- ScoliosisHPOHP:0002650
- 10 of 15 reported patients
- Occasional (5% to 29% of cases)
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- B4GALNT1HGNC:4117
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2022
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Moderate · Ambry Genetics · Autosomal recessive · 2018
- Supportive · Orphanet · Autosomal recessive · 2021
Where it sits
Other names
4 names
Resolves to: hereditary spastic paraplegia 26
- Also called
- autosomal recessive spastic paraplegia type 26GM2 synthase deficiencyhereditary spastic paraplegia type 26SPG26