seizures-scoliosis-macrocephaly syndrome
Findings
No curated finding names seizures-scoliosis-macrocephaly syndrome yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Seizures-scoliosis-macrocephaly syndrome is a rare, genetic neurometabolic disorder characterized by seizures, macrocephaly, delayed motor milestones, moderate intellectual disability, scoliosis with no exostoses, muscular hypotonia present since birth, as well as renal dysfunction. Coarse facial features (including hypertelorism and long hypoplastic philtrum) and bilateral cryptorchidism (in males) are also commonly reported. Additional manifestations include abnormal gastrointestinal motility (resulting in constipation, diarrhea, gastroesophageal reflux and dysphagia), gait disturbances, strabismus and ventricular septal defects.
Definition from the Mondo Disease Ontology (MONDO:0014731), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Congenital onset · Childhood onset
HPO, annotations 2026-09-02
Features
44 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.
- CryptorchidismHPOHP:0000028
- 3 of 3 reported patients · Male
- Frequent (30% to 79% of cases)
- Global developmental delayHPOHP:0001263
- 4 of 4 reported patients
- Very frequent (80% to 99% of cases)
- HypotoniaHPOHP:0001252
- 4 of 4 reported patients
- Frequent (30% to 79% of cases)
- MacrocephalyHPOHP:0000256
- 4 of 4 reported patients
- Frequent (30% to 79% of cases)
- Moderate intellectual disabilityHPOHP:0002342
- 4 of 4 reported patients
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.
- EXT2HGNC:3513
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2019
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal recessive · 2021
- Limited · Ambry Genetics · Autosomal recessive · 2019
Where it sits
- A kind of
Other names
3 names
Resolves to: seizures-scoliosis-macrocephaly syndrome
- Also called
- seizures, scoliosis, and macrocephaly syndromeSSM syndromeSSMS