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Start free with EleplanMonosomy 9p syndrome
ORPHA:261112Malformation syndrome
Also called 9p deletion syndrome · 9p- syndrome · Alfi syndrome
What it is
Monosomy 9p is a rare chromosomal anomaly characterized by psychomotor developmental delay, facial dysmorphism (trigonocephaly, midface hypoplasia, upslanting palpebral fissures, dysplastic small ears, flat nasal bridge with anteverted nostrils and long philtrum, micrognathia, choanal atresia, short neck), single umbilical artery, omphalocele, inguinal or umbilical hernia, genital abnormalities (hypospadia, cryptorchidism), muscular hypotonia and scoliosis.
Key facts
- Age of onset
- Antenatal, Neonatal
- Classified as
- Malformation syndrome
Signs and symptoms
Very common80–99%
23- Abnormal dermatoglyphics
- Abnormality of the antihelix
- Anotia
- Anteverted nares
- Blepharophimosis
- Brachycephaly
- Depressed nasal bridge
- Global developmental delay
- High palate
- Hypertelorism
- Intellectual disability
- Long philtrum
- Low posterior hairline
- Low-set ears
- Malar flattening
- Micrognathia
- Microtia
- Proximal placement of thumb
- Short neck
- Thin nail
- Trigonocephaly
- Webbed neck
- Wide intermamillary distance
Common30–79%
20These 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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