Smith-Magenis syndrome
Findings
No curated finding names Smith-Magenis syndrome yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Smith-Magenis syndrome (SMS) is a complex genetic disorder characterized by variable intellectual deficit, sleep disturbance, craniofacial and skeletal anomalies, psychiatric disorders, and speech and motor delay.
Definition from the Mondo Disease Ontology (MONDO:0008434), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal dominant inheritance · Sporadic
- Onset and course
- Neonatal onset
HPO, annotations 2026-09-02
Features
129 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.
- Global developmental delayHPOHP:0001263
- 105 of 105 reported patients
- Very frequent (80% to 99% of cases)
- HypotoniaHPOHP:0001252
- 2 of 2 reported patients
- Very frequent (80% to 99% of cases)
- Intellectual disabilityHPOHP:0001249
- 2 of 2 reported patients
- Very frequent (80% to 99% of cases)
- Midface retrusionHPOHP:0011800
- 2 of 2 reported patients
- Very frequent (80% to 99% of cases)
- Mild global developmental delayHPOHP:0011342
- 2 of 2 reported patients
- Square faceHPOHP:0000321
Show the remaining 117
- BrachydactylyHPOHP:0001156
- 22 of 27 reported patients
- Very frequent (80% to 99% of cases)
- Hoarse voiceHPOHP:0001609
- 68 of 84 reported patients
- Very frequent (80% to 99% of cases)
- Abnormal pineal melatonin secretionHPOHP:0012689
- Very frequent (80% to 99% of cases)
- Abnormal speech patternHPOHP:0002167
- Very frequent (80% to 99% of cases)
- Abnormal tracheobronchial morphologyHPOHP:0005607
- Frequent (30% to 79% of cases)
- Very frequent (80% to 99% of cases)
- Abnormality of the dentitionHPO
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.
- RAI1HGNC:9834
- Definitive · Ambry Genetics · Autosomal dominant · 2015
- Definitive · ClinGen · Autosomal dominant · 2018
- Definitive · G2P · Autosomal dominant · 2015
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal dominant · 2020
- Strong · PanelApp Australia · Autosomal dominant · 2025
- Supportive · Orphanet · Autosomal dominant · 2021
Where it sits
Other names
5 names
Resolves to: Smith-Magenis syndrome
- Also called
- 17p11.2 microdeletion syndromechromosome 17P11.2 deletion syndromeSmith Magenis SyndromeSmith-Magenis syndrome, Isolated casesSMS