ring chromosome 18
Findings
No curated finding names ring chromosome 18 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Ring chromosome 18 syndrome is an autosomal anomaly characterized by variable clinical features, most commonly including hypotonia, neonatal feeding and respiratory difficulties, microcephaly, global developmental delay and intellectual disability, growth hormone deficiency, hypothyroidism, hearing loss, aural atresia, dysmorphic facial features and behavioral characteristics.
Definition from the Mondo Disease Ontology (MONDO:0015434), read 2026-09-29. CC BY 4.0.
Features
14 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.
- Cognitive impairmentHPOHP:0100543
- Frequent (30% to 79% of cases)
- Global developmental delayHPOHP:0001263
- Frequent (30% to 79% of cases)
- Intellectual disabilityHPOHP:0001249
- Frequent (30% to 79% of cases)
- MicrocephalyHPOHP:0000252
- Frequent (30% to 79% of cases)
- Short statureHPOHP:0004322
- Frequent (30% to 79% of cases)
- Abnormal internal genitaliaHPOHP:0000812
- Occasional (5% to 29% of cases)
- Cleft lipHPO
Show the remaining 2
- SeizureHPOHP:0001250
- Occasional (5% to 29% of cases)
- Talipes equinovarusHPOHP:0001762
- Occasional (5% to 29% of cases)
Where it sits
Other names
2 names
Resolves to: ring chromosome 18
- Also called
- Chromosome 18 RingRing chromosome type 18