20q13.33 microdeletion syndrome

Caring for someone with this diagnosis? Eleplan keeps diagnoses, medications, documents and every specialist in one plan.

Start free with Eleplan

20q13.33 microdeletion syndrome

ORPHA:261311Malformation syndrome

Also called Del(20)(q13.33) · Monosomy 20q13.33

What it is

A rare chromosomal anomaly syndrome resulting from the partial deletion of the long arm of chromosome 20 with a highly variable phenotype typically characterized by hypotonia, intellectual disability, cognitive and language deficits (including decreased or absent speech), pre and post-natal growth retardation, feeding difficulties, microcephaly, and malformed hands and feet. Neurodevelopmental disorders (including hyperactivity, social interactive problems and autism spectrum disorder), seizures and dysmorphic facial features (high forehead, hypertelorism, malformed ears, broad nasal bridge, bulbous nasal tip, thin upper lip, small chin) are frequently associated.

Key facts

Age of onset
Neonatal
Inheritance
Not applicable
Classified as
Malformation syndrome

Signs and symptoms

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

Q93.5filed under a broader ICD-10 category — shared with 122 other rare diseases

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

MONDO 0016843UMLS C4518823

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.