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Start free with Eleplan20p13 microdeletion syndrome
ORPHA:313781Malformation syndrome
Also called 20p subtelomeric deletion syndrome · Del(20)(p13) · Monosomy 20p13
What it is
20p13 microdeletion syndrome is a rare chromosomal anomaly characterized by developmental delay, mild to moderate intellectual disability, epilepsy, and unspecific dysmorphic signs. High palate, delayed permanent tooth eruption, hypoplastic fingernails, clinodactyly and short fingers have also been reported.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Infancy, Neonatal
- Inheritance
- Autosomal dominant, Not applicable
- 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
Common30–79%
16- Abnormal pinna morphology
- Decreased body weight
- Delayed speech and language development
- EEG abnormality
- Failure to thrive in infancy
- Highly arched eyebrow
- Intellectual disability
- Low-set ears
- Poor head control
- Prominent forehead
- Prominent nasal bridge
- Seizure
- Small nail
- Smooth philtrum
- Thin upper lip vermilion
- Wide anterior fontanel
Sometimes5–29%
18- Brachydactyly
- Clinodactyly
- Deeply set eye
- Downslanted palpebral fissures
- Finger syndactyly
- Hypertelorism
- Hypoplastic helices
- Macrocephaly
and 10 more in this range
These 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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