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Start free with EleplanDistal deletion 9p syndrome
ORPHA:1642Malformation syndrome
Also called Distal monosomy 9p · Monosomy 9pter · Telomeric deletion 9p
What it is
Distal monosomy 9p is a rare chromosomal anomaly syndrome, resulting from a partial deletion of the short arm of chromosome 9, with a highly variable phenotype typically characterized by intellectual disability, craniofacial dysmorphism (trigonocephaly, upslanting palpebral fissures, hypoplastic supraorbital ridges), abnormal digits (long middle phalanges with short distal phalanges), as well as frequent association with genitourinary abnormalities (cryptorchidism, hypospadias, ambiguous genitalia, 46,XY testicular dysgenesis). Congenital hypothyroidism and cardiovascular defects have been reported in some cases. Patients present an increased risk for gonadoblastoma.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- 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%
15Common30–79%
10These 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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