maternal uniparental disomy of chromosome 20
Findings
No curated finding names maternal uniparental disomy of chromosome 20 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Maternal uniparental disomy of chromosome 20 (UPD 20) is a very rare chromosomal anomaly in which both copies of chromosome 20 are inherited from the mother. The main feature described is prenatal and postnatal growth retardation. Microcephaly, minor dysmorphic features and psychomotor developmental delay have been occasionally reported. Maternal UPD20 is most often ascertained by a mosaic trisomy 20 pregnancy.
Definition from the Mondo Disease Ontology (MONDO:0019917), read 2026-09-29. CC BY 4.0.
Features
30 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.
- Failure to thriveHPOHP:0001508
- 8 of 8 reported patients · Infantile onset
- Severe short statureHPOHP:0003510
- 8 of 8 reported patients
- Feeding difficulties in infancyHPOHP:0008872
- Very frequent (80% to 99% of cases)
- Postnatal growth retardationHPOHP:0008897
- Very frequent (80% to 99% of cases)
- ClinodactylyHPOHP:0030084
- 2 of 8 reported patients
- Frequent (30% to 79% of cases)
- Decreased body weightHPOHP:0004325
- Frequent (30% to 79% of cases)
Show the remaining 18
- Short statureHPOHP:0004322
- Frequent (30% to 79% of cases)
- Small for gestational ageHPOHP:0001518
- Frequent (30% to 79% of cases)
- Triangular faceHPOHP:0000325
- 1 of 8 reported patients
- Frequent (30% to 79% of cases)
- Generalized hypotoniaHPOHP:0001290
- 4 of 8 reported patients
- Asymmetric growthHPOHP:0100555
- Occasional (5% to 29% of cases)
- MicrognathiaHPOHP:0000347
- Occasional (5% to 29% of cases)
Where it sits
Other names
3 names
Resolves to: maternal uniparental disomy of chromosome 20
- Also called
- maternal uniparental disomy of chromosome type 20maternal UPD(20)UPD(20)mat