Skip to
  1. Homepage
  2. Rare diseases
  3. Search
Simple search

Simple search

*
(*) mandatory field





 

Other search option(s)

Monosomy 22q13

ORPHA48652
Synonym(s) 22q13 deletion
Phelan-McDermid syndrome
Prevalence Unknown
Inheritance Not applicable
or Unknown
Age of onset Infancy
Neonatal
ICD-10
  • Q93.5
OMIM
UMLS -
MeSH -
MedDRA -

Summary

Monosomy 22q13 syndrome (deletion 22q13.3 syndrome or Phelan-McDermid syndrome) is a chromosome microdeletion syndrome characterized by neonatal hypotonia, global developmental delay, normal to accelerated growth, absent to severely delayed speech, and minor dysmorphic features. Due to lack of clinical recognition and often insufficient laboratory testing, the syndrome is underdiagnosed and its true incidence remains unknown. The deletion occurs with equal frequency in males and females and has been reported in mosaic and non-mosaic forms. Common physical traits include long eye lashes, large or unusual ears, relatively large hands, dysplastic toenails, full brow, dolicocephaly, full cheeks, bulbous nose, and pointed chin. Behavior is autistic-like with decreased perception of pain and habitual chewing or mouthing. The loss of 22q13.3 can result from a simple deletion, translocation, ring chromosome formation or, less commonly, from structural changes affecting the long arm of chromosome 22, specifically the region containing the SHANK3 gene. The diagnosis of monosomy 22q13 syndrome should be considered in all cases of hypotonia of unknown etiology and in individuals with absent speech. Although the deletion can sometimes be detected by high resolution chromosome analysis, fluorescence in situ hybridization (FISH) or array comparative genomic hybridization (CGH) is recommended for confirmation. Differential diagnosis includes syndromes associated with hypotonia, developmental delay, speech delay and/or autistic-like behavior (Prader-Willi, Angelman, Williams, Smith-Magenis, Fragile X, Sotos, FG, trichorhinophalangeal and velocardiofacial syndromes, autism spectrum disorders and cerebral palsy; see these terms). Genetic counseling is recommended and laboratory studies of the parents should be considered to identify cryptic rearrangements and detect parental mosaicism. Prenatal diagnosis should be offered for future pregnancies in families with inherited rearrangements. Individuals with monosomy 22q13 should have routine examinations by the primary care physician, as well as genetic evaluations with referral to specialists if neurological, gastrointestinal, renal, or other systemic problems are suspected. Affected individuals benefit from early intervention programs, intense occupational and communication therapies, adaptive exercise and sport programs, and other therapies to strengthen their muscles and increase their communication skills. No apparent life-threatening organic abnormalities accompany the diagnosis of monosomy 22q 13.

Expert reviewer(s)

  • Dr Mary C PHELAN

(*) Required fields.

Attention: 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.


Captcha image

Detailed information

Review article
  • EN (2008)
Guidance for genetic testing
  • EN (2010,pdf)
Clinical genetics review
  • EN (2011)
Get Acrobat Reader
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.