Caring for someone with this diagnosis? Eleplan keeps diagnoses, medications, documents and every specialist in one plan.
Start free with EleplanTrisomy 4p syndrome
ORPHA:1738Malformation syndrome
Also called Duplication 4p · Duplication of the short arm of chromosome 4 · Trisomy of the short arm of chromosome 4
What it is
Trisomy 4p is a rare chromosomal anomaly syndrome, resulting from the partial duplication of the short arm of chromosome 4, with a highly variable phenotype, typically characterized by pre- and postnatal growth delay, psychomotor developmental delay and craniofacial dysmorphism (microcephaly, prominent glabelle, hypertelorism, enlarged ears with abnormal helix and antihelix, bulbous nose with flat or depressed nasal bridge, long philtrum, retrognathia with pointed chin). Additional features include skeletal (rocker bottom feet, arachnodactyly, camptodactyly) and renal malformations, cardiac defects, ocular abnormalities and abnormal genitalia in males.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Antenatal, Infancy, Neonatal
- Classified as
- Malformation syndrome
Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.
Signs and symptoms
Very common80–99%
20- Abnormal hair pattern
- Abnormality of chromosome segregation
- Abnormality of the antihelix
- Abnormality of the dentition
- Abnormal palate morphology
- Carious teeth
- Cognitive impairment
- Depressed nasal bridge
- Hypertelorism
- Hypotonia
- Low anterior hairline
- Macrotia
- Microcephaly
- Posteriorly rotated ears
- Round face
- Short neck
- Short stature
- Smooth philtrum
- Thick eyebrow
- Wide intermamillary distance
Sometimes5–29%
5These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.
ICD-10 codes
ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.
Related health topics
Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.
Cross-references
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
Powered by Eleplan
A rare diagnosis is just the start. Eleplan keeps the whole care plan in one place.
Diagnoses, medications, documents, appointments, and the whole care team — organized and always in sync, so you are not retelling the same story to every new specialist. With Ellie, your AI care assistant, on top of it. Free to start.