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Start free with EleplanHoloprosencephaly-postaxial polydactyly syndrome
ORPHA:2166Malformation syndrome
Also called Pseudo-trisomy 13 syndrome
What it is
Holoprosencephaly-postaxial polydactyly syndrome associates, in chromosomally normal neonates, holoprosencephaly, severe facial dysmorphism, postaxial polydactyly and other congenital abnormalities, suggestive of trisomy 13.
Key facts
- Age of onset
- Antenatal, Neonatal
- Inheritance
- Autosomal recessive
- Classified as
- Malformation syndrome
Signs and symptoms
Very common80–99%
5Common30–79%
18- Abnormal cardiac septum morphology
- Abnormal cardiovascular system morphology
- Abnormality of the hypothalamus-pituitary axis
- Abnormal lung lobation
- Adrenal hypoplasia
- Ambiguous genitalia
- Anal atresia
- Aplasia/Hypoplasia of the corpus callosum
- Cleft palate
- Cryptorchidism
- Holoprosencephaly
- Hydrocephalus
- Hypospadias
- Hypotonia
- Microcephaly
- Orofacial cleft
- Posteriorly rotated ears
- Thyroid hypoplasia
Sometimes5–29%
13- Abnormal localization of kidney
- Absent nares
- Cerebellar hypoplasia
- Cyclopia
- Encephalocele
- Intestinal malrotation
- Micrognathia
- Narrow mouth
and 5 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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