duplication/inversion 15q11
Findings
No curated finding names duplication/inversion 15q11 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Isodicentric chromosome 15 syndrome is a chromosome abnormality that affects many different parts of the body. As the name suggests, people with this condition have an extra chromosome (called an isodicentric chromosome 15) which is made of two pieces of chromosome 15 that are stuck together end-to-end. Although the severity of the condition and the associated features vary from person to person, common signs and symptoms include poor muscle tone in newborns; developmental delay; mild to severe intellectual disability; delayed or absent speech; behavioral abnormalities; and seizures. Most cases of isodicentric chromosome 15 syndrome occur sporadically in people with no family history of the condition. Treatment is based on the signs and symptoms present in each person.
Definition from the Mondo Disease Ontology (MONDO:0018027), read 2026-09-29. CC BY 4.0.
Features
41 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.
- Autistic behaviorHPOHP:0000729
- Very frequent (80% to 99% of cases)
- DroolingHPOHP:0002307
- Very frequent (80% to 99% of cases)
- Generalized hypotoniaHPOHP:0001290
- Very frequent (80% to 99% of cases)
- Joint hypermobilityHPOHP:0001382
- Very frequent (80% to 99% of cases)
- EcholaliaHPOHP:0010529
- Frequent (30% to 79% of cases)
- Feeding difficultiesHPOHP:0011968
- Frequent (30% to 79% of cases)
- Hyperactivity
Show the remaining 29
- Severe receptive language delayHPOHP:0011352
- Frequent (30% to 79% of cases)
- 2-3 toe syndactylyHPOHP:0004691
- Occasional (5% to 29% of cases)
- Abnormal brain morphologyHPOHP:0012443
- Occasional (5% to 29% of cases)
- Abnormal facial shapeHPOHP:0001999
- Occasional (5% to 29% of cases)
- Aggressive behaviorHPOHP:0000718
- Occasional (5% to 29% of cases)
- BrachycephalyHPOHP:0000248
- Occasional (5% to 29% of cases)
Where it sits
- A kind of
Other names
7 names
Resolves to: duplication/inversion 15q11
- Also called
- Duplication/inversion type 15q11idic(15)Inv dup(15)Invdup(15)Isodicentric 15 chromosomenon-distal tetrasomy 15qnon-telomeric tetrasomy 15q