DiGeorge syndrome

Author: Brian Wu PhD. MD Candidate, Keck School of Medicine, Los Angeles, USA; Chief Editor: Dr Amanda Oakley, Dermatologist, Hamilton, New Zealand, October 2015.

Synonyms:

Velocardiofacial syndrome, Shprintzer syndrome, CATCH22, 22q11.2 deletion syndrome, DiGeorge sequence, Agenesis of the parathyroid and thymus glands, Third and fourth pharyngeal pouch syndrome, Thymic hypoplasia syndrome, Pharyngeal pouch syndrome, Thymic parathyroid aplasia, Third and fourth pharyngeal arch syndrome, Branchial arch syndrome, DiGeorge anomaly, Sedlackova syndrome, Conotruncal anomaly face syndrome, Cayler cardiofacial syndrome, Takao syndrome, Microdeletion 22q11.2, MIM 188400

Categories:

Developmental disorder

Subcategories:

Immunodeficiency syndrome, Clinical features and complications of DiGeorge syndrome, Diagnosis of DiGeorge syndrome, Treatment of DiGeorge syndrome

ICD-10:

D82.1

ICD-11:

LD44.N0

SNOMED CT:

77128003

What is DiGeorge syndrome?

DiGeorge syndrome is a rare primary immunodeficiency disorder with a wide range of presenting signs and symptoms. It is due to chromosomal defects that arise early in gestation.

DiGeorge syndrome is also called velocardiofacial syndrome, shprintzer syndrome, CATCH22 and 22q11.2 deletion syndrome.

What causes DiGeorge syndrome?

DiGeorge syndrome is caused by dysfunctional development of certain cells and tissues in utero. Approximately 90% of the patients with DiGeorge syndrome have a deletion of a segment of 30–40 genes on chromosome 22. Generally, this is considered to be the consequence of a random event in either the egg or the sperm, but more rarely it can be passed on from parent to child.

Genetics of DiGeorge syndrome *

*Image courtesy Genetics 4 Medics

What are the signs and symptoms of DiGeorge syndrome?

Because there is great phenotypic variability associated with this syndrome, one patient may present with vastly different symptoms from another. Possible symptoms include:

Respiratory: difficult breathing, cyanosis
Musculoskeletal: twitching/spasms of the periorbital muscles and muscles in the limbs, muscle weakness and poor tone
Immunological: frequent infections
Neurological/behavioural: delayed development, learning disabilities or behavioural problems

DiGeorge syndrome patients also generally present with distinctive facial characteristics, including:

An under-developed chin
Low-set ears
Wide-set eyes
A deep groove in the upper lip
Cleft palate or other palate abnormalities

What complications can arise from DiGeorge syndrome?

Possible complications arising from DiGeorge syndrome are varied and may include:

Cardiac conditions, including heart defects such as ventricular septal defect, truncus arteriosus or tetralogy of Fallot.
Endocrinological issues including hypoparathyroidism or thymus gland dysfunction
Psychiatric/neurological issues such as attention deficit hyperactivity disorder, autism spectrum disorder, depression, anxiety and schizophrenia
Sensory disorders such as auditory and/or visual impairment
Immunological: increased susceptibility to bacterial, viral and fungal infections and an increased risk for autoimmune disorders, most commonly idiopathic thrombocytopenic purpura, autoimmune haemolytic anaemia, autoimmune arthritis and autoimmune thyroid dysfunction.

How is DiGeorge syndrome diagnosed?

DiGeorge syndrome is diagnosed based on patient signs and symptoms, the presence of a heart defect (though this by itself is not diagnostic), and genetic testing, fluorescence in situ hybridisation (FISH), is used to determine deletion in chromosome 22.

How is DiGeorge syndrome treated?

There is no cure for DiGeorge syndrome. Treatment is based on correcting or managing secondary problems wherever possible. This can include:

Surgical correction of a cleft palate or cardiovascular defects
Transplantation of thymus tissue for a severe dysfunction of the thymus gland
Calcium and vitamin D supplements for hypoparathyroidism
Speech, physical or occupational therapy to counteract developmental delays/deficits
Anti-depressants, anti-anxiety agents or other psychotropic drugs and therapy to treat psychiatric disorders