trisomy 12p
Findings
No curated finding names trisomy 12p yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Trisomy 12p is an extremely rare chromosomal disorder (over 30 cases reported worldwide) characterized by craniofacial malformations (round face, prominent cheeks, high bulging forehead, broad and flat nasal bridge, short nose with anteverted nostrils, long philtrum, prominent and everted lower lip, low-set ears, abnormally folded helix, protuberant antihelix), postnatal growth retardation, mental and psychomotor retardation, generalized hypotonia, abnormally short wide hands and/or other abnormalities.
Definition from the Mondo Disease Ontology (MONDO:0015723), read 2026-09-29. CC BY 4.0.
Features
31 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.
- Abnormal antihelix morphologyHPOHP:0009738
- Very frequent (80% to 99% of cases)
- Abnormality of chromosome segregationHPOHP:0002916
- Very frequent (80% to 99% of cases)
- Clinodactyly of the 5th fingerHPOHP:0004209
- Very frequent (80% to 99% of cases)
- Downturned corners of mouthHPOHP:0002714
- Very frequent (80% to 99% of cases)
- EpicanthusHPOHP:0000286
- Very frequent (80% to 99% of cases)
- Everted lower lip vermilionHPOHP:0000232
- Very frequent (80% to 99% of cases)
Show the remaining 19
- Malar flatteningHPOHP:0000272
- Very frequent (80% to 99% of cases)
- MicrognathiaHPOHP:0000347
- Very frequent (80% to 99% of cases)
- Short neckHPOHP:0000470
- Very frequent (80% to 99% of cases)
- Short noseHPOHP:0003196
- Very frequent (80% to 99% of cases)
- Thick eyebrowHPOHP:0000574
- Very frequent (80% to 99% of cases)
- Thickened nuchal skin foldHPOHP:0000474
- Very frequent (80% to 99% of cases)
Where it sits
Other names
2 names
Resolves to: trisomy 12p
- Also called
- Duplication 12ptrisomy type 12p