mosaic trisomy 9
Findings
No curated finding names mosaic trisomy 9 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Mosaic trisomy 9 is a chromosomal abnormality that can affect may parts of the body. In people affected by this condition, some of the body's cells have three copies of chromosome 9 (trisomy), while other cells have the usual two copies of this chromosome. The signs and symptoms vary but may include mild to severe intellectual disability, developmental delay, growth problems (both before and after birth), congenital heart defects, and/or abnormalities of the craniofacial (skull and face) region. Most cases are not inherited; it often occurs sporadically as a random event during the formation of the reproductive cells (egg and sperm) or as the fertilized egg divides. Treatment is based on the signs and symptoms present in each person.
Definition from the Mondo Disease Ontology (MONDO:0020490), read 2026-09-29. CC BY 4.0.
Features
62 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
- Very frequent (80% to 99% of cases)
- Global developmental delayHPOHP:0001263
- Very frequent (80% to 99% of cases)
- Intellectual disabilityHPOHP:0001249
- Very frequent (80% to 99% of cases)
- Low-set earsHPOHP:0000369
- Very frequent (80% to 99% of cases)
- MicrophthalmiaHPOHP:0000568
- Very frequent (80% to 99% of cases)
- Bulbous noseHPOHP:0000414
- Frequent (30% to 79% of cases)
- Finger clinodactyly
Show the remaining 50
- Large fontanellesHPOHP:0000239
- Frequent (30% to 79% of cases)
- Limitation of joint mobilityHPOHP:0001376
- Frequent (30% to 79% of cases)
- MicrognathiaHPOHP:0000347
- Frequent (30% to 79% of cases)
- OligohydramniosHPOHP:0001562
- Frequent (30% to 79% of cases)
- Rocker bottom footHPOHP:0001838
- Frequent (30% to 79% of cases)
- Short neckHPOHP:0000470
- Frequent (30% to 79% of cases)
Where it sits
- A kind of
Other names
1 name
Resolves to: mosaic trisomy 9
- Also called
- Mosaic trisomy type 9