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Start free with Eleplan2q23.1 microduplication syndrome
ORPHA:313947Malformation syndrome
Also called Dup(2)(q23.1) · Trisomy 2q23.1
What it is
2q23.1 microduplication syndrome is a rare chromosomal anomaly syndrome, resulting from the partial duplication of the long arm of chromosome 2, primarily characterized by global developmental delay, hypotonia, autistic-like features and behavioural problems. Craniofacial dysmorphism (arched eyebrows, hypertelorism, bilateral ptosis, prominent nose, wide mouth, micro/retrognathia) and an affable personality are also commonly associated. Minor digital anomalies (fifth finger clinodactyly and large, broad first toe) have occasionally been reported.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Infancy, Neonatal
- Inheritance
- Not applicable, Unknown
- 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%
8Common30–79%
20- Abnormal foot morphology
- Abnormality of the dentition
- Abnormality of the hand
- Bilateral ptosis
- Broad-based gait
- Broad hallux
- Bulbous nose
- Clinodactyly of the 5th finger
- Dental crowding
- Highly arched eyebrow
- Hypotelorism
- Long eyelashes
- Midface retrusion
- Poor coordination
- Prominent nasal tip
- Prominent nose
- Reduced eye contact
- Sleep abnormality
- Strabismus
- Thin upper lip vermilion
Sometimes5–29%
8These 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.
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