22q13.3 deletion syndrome
Last updated 13 Jul 2023
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22q13.3 deletion syndrome, which is also known as Phelan-McDermid syndrome, is a disorder caused by the loss of a small piece of chromosome 22. The deletion occurs near the end of the chromosome at a location designated q13.3.
Description
22q13.3 deletion syndrome, which is also known as Phelan-McDermid syndrome, is a disorder caused by the loss of a small piece of chromosome 22. The deletion occurs near the end of the chromosome at a location designated q13.3.
The features of 22q13.3 deletion syndrome vary widely and involve many parts of the body. Characteristic signs and symptoms include developmental delay, moderate to profound intellectual disability, decreased muscle tone (hypotonia), and absent or delayed speech. Some people with this condition have autism spectrum disorder or autistic-like characteristics that affects communication and social interaction, such as poor eye contact, sensitivity to touch, and aggression. They may also chew on non-food items such as clothing. Less frequently, people with this condition have seizures or lose skills they had already acquired (developmental regression).
Individuals with 22q13.3 deletion syndrome tend to have a decreased sensitivity to pain. Many also have a reduced ability to sweat, which can lead to a greater risk of overheating and dehydration. Some people with this condition have episodes of frequent vomiting and nausea (cyclic vomiting) and backflow of stomach acids into the esophagus (gastroesophageal reflux).
People with 22q13.3 deletion syndrome typically have distinctive facial features, including a long, narrow head; prominent ears; a pointed chin; droopy eyelids (ptosis); and deep-set eyes. Other physical features seen with this condition include large and fleshy hands and/or feet, a fusion of the second and third toes (syndactyly), and small or abnormal toenails. Some affected individuals have rapid (accelerated) growth.
Inheritance patterns
The source lists the following possible inheritance patterns: Autosomal dominant. More than one pattern can apply in different cases.
Related genes
Other names
22q13 deletion syndrome
Deletion 22q13 syndrome
Deletion 22q13.3 syndrome
Monosomy 22q13
Phelan-McDermid syndrome
Further reading and references
- 22q13.3 deletion syndrome; MedlinePlus, National Library of Medicine.
- Bonaglia MC, Giorda R, Mani E, Aceti G, Anderlid BM, Baroncini A, Pramparo T, Zuffardi O. Identification of a recurrent breakpoint within the SHANK3 gene in the 22q13.3 deletion syndrome. J Med Genet. 2006 Oct;43(10):822-8. doi: 10.1136/jmg.2005.038604. Epub 2005 Nov 11.
- Cusmano-Ozog K, Manning MA, Hoyme HE. 22q13.3 deletion syndrome: a recognizable malformation syndrome associated with marked speech and language delay. Am J Med Genet C Semin Med Genet. 2007 Nov 15;145C(4):393-8. doi: 10.1002/ajmg.c.30155.
- Havens JM, Visootsak J, Phelan MC, Graham JM Jr. 22q13 deletion syndrome: an update and review for the primary pediatrician. Clin Pediatr (Phila). 2004 Jan-Feb;43(1):43-53. doi: 10.1177/000992280404300106.
- Koolen DA, Reardon W, Rosser EM, Lacombe D, Hurst JA, Law CJ, Bongers EM, van Ravenswaaij-Arts CM, Leisink MA, van Kessel AG, Veltman JA, de Vries BB. Molecular characterisation of patients with subtelomeric 22q abnormalities using chromosome specific array-based comparative genomic hybridisation. Eur J Hum Genet. 2005 Sep;13(9):1019-24. doi: 10.1038/sj.ejhg.5201456.
- Manning MA, Cassidy SB, Clericuzio C, Cherry AM, Schwartz S, Hudgins L, Enns GM, Hoyme HE. Terminal 22q deletion syndrome: a newly recognized cause of speech and language disability in the autism spectrum. Pediatrics. 2004 Aug;114(2):451-7. doi: 10.1542/peds.114.2.451.
- Phelan MC, Rogers RC, Saul RA, Stapleton GA, Sweet K, McDermid H, Shaw SR, Claytor J, Willis J, Kelly DP. 22q13 deletion syndrome. Am J Med Genet. 2001 Jun 15;101(2):91-9. doi: 10.1002/1096-8628(20010615)101:23.0.co;2-c.
- Phelan MC. Deletion 22q13.3 syndrome. Orphanet J Rare Dis. 2008 May 27;3:14. doi: 10.1186/1750-1172-3-14.
- Wilson HL, Wong AC, Shaw SR, Tse WY, Stapleton GA, Phelan MC, Hu S, Marshall J, McDermid HE. Molecular characterisation of the 22q13 deletion syndrome supports the role of haploinsufficiency of SHANK3/PROSAP2 in the major neurological symptoms. J Med Genet. 2003 Aug;40(8):575-84. doi: 10.1136/jmg.40.8.575.
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