Search for a rare disease

* (*) mandatory field

Other search option(s)

Suggest an update

(*) Required fields.


Only comments seeking to improve the quality and accuracy of information on the Orphanet website are accepted. For all other comments, please send your remarks via contact us. Only comments written in English can be processed.

Orphanet doesn't provide personalised answers. To get in touch with the Orphanet team, please contact

Information provided in your contribution (including your email address) will be stocked in .CSV files that will be sent as an email to Orphanet's teams. These emails might be conserved in the teams' mailboxes, in our backoffice servers but will not be registered in our databases (for more information see our section General Data Protection Regulation and data privacy (GDPR) and Confidentiality).

Captcha image

12p12.1 microdeletion syndrome

Disease definition

A rare chromosomal anomaly syndrome, resulting from the partial deletion of the short arm of chromosome 12, characterized by intellectual disability, global developmental delay with prominent language impairment, behavioral abnormalities and mild facial dysmorphism (incl. frontal bossing, downslanting palpebral fissures, epicanthal folds, broad, depressed nasal bridge with bulbous nasal tip, low-set ears with underdeveloped helices). Other associated features may include skeletal abnormalities (butterfly vertebrae, scoliosis), strabismus, optic nerve hypoplasia, and brain malformations.


Classification level: Subtype of disorder
  • Synonym(s):
    • Del(12)(p12.1)
    • Monosomy 12p12.1
  • Prevalence: <1 / 1 000 000
  • Inheritance: Autosomal dominant or Not applicable 
  • Age of onset: Infancy, Neonatal
  • ICD-10: Q93.5
  • OMIM: 616803
  • UMLS: C4755260
  • MeSH: -
  • GARD: -
  • MedDRA: -

Detailed information

General public

ERN produced/endorsed by ERN(s)   FSMR produced/endorsed by FSMR(s)
The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment.