DiGeorge syndrome, otherwise referred to as 22q11.2 deletion syndrome, is a chromosomal disorder that typically affects the 22nd chromosome at the q11.2 location, with as many as 90% of cases exhibiting this deletion feature.1-3
This condition has also been known as velocardiofacial syndrome, conotruncal syndrome, Shprintzen syndrome and CATCH22, as well as many others.1-3
Experts estimate that DiGeorge syndrome affects 1 in 4,000 people. However, due to variability in presenting features, many people may be underdiagnosed or misdiagnosed.2,3
DiGeorge syndrome causes several body systems to develop poorly and can lead to medical problems as varied as heart defects, behavioral problems and a cleft palate.
Fast facts on DiGeorge syndrome
Here are some key points about DiGeorge syndrome. More detail and supporting information can be found in the main article.
- DiGeorge syndrome is also known as Cayler cardiofacial syndrome and Sedlackova syndrome
- The condition is typically referred to as 22q11.2 deletion syndrome as this most accurately reflects its origins
- The deletion of genes from the 22nd chromosome usually occurs randomly; the condition is rarely inherited
- The symptoms of DiGeorge syndrome depend on what organ system has been affected by the disorder
- DiGeorge syndrome is often diagnosed with a specific blood test
- Treatment for DiGeorge syndrome usually requires a number of specialists from different fields of medicine.
Causes of DiGeorge Syndrome
DiGeorge syndrome is caused by the deletion of a segment of chromosome 22.
DiGeorge syndrome is caused by the deletion of the 22q11.2 segment in one of the two copies of chromosome 22, affecting approximately 30-40 genes. Many of these genes are yet to be fully understood by scientists.1,3
The development of DiGeorge syndrome is typically a random event that occurs during fertilization on either the maternal or paternal side, or during the time of fetal development.1-3
Most cases of DiGeorge syndrome are not inherited in nature, as most people with DiGeorge syndrome do not have a familial history of the condition, although it can be passed from an affected parent to a child; this occurs in approximately 10% of DiGeorge syndrome cases.1,3
Symptoms of DiGeorge Syndrome
Signs and symptoms of DiGeorge syndrome are varied and include:1-3
- Respiratory difficulties
- Mouth, arm, throat or hand spasms
- Frequent infections
- Abnormal facial features including underdeveloped chin, low-set ears and wide-set eyes
- Cleft palate or other palate disorders
- Delayed growth
- Poor muscle tone
- Delayed development, delayed speech and other learning delays
- Behavioral problems such as ADHD
- Psychiatric disorders such as schizophrenia
- Autoimmune diseases such as idiopathic thrombocytopenia purpura, autoimmune hemolytic anemia, autoimmune arthritis and autoimmune thyroid disease
- Parathyroid gland abnormalities such as seizures, hypoparathyroidism and abnormal calcium and phosphorous metabolism
- Thymus gland abnormalities such as T-lymphocyte deficits
- Blue skin color (cyanosis) which is secondary to poor circulation caused by heart defects – these typically affect the aorta and may include ventricular septal defect (hole between the lower heart chambers, truncus arteriosus (missing heart vessel) and tetralogy of Fallot (combination of four abnormal heart structures).
Other symptoms may include hearing impairment, visual abnormalities and altered kidney function
Due to the significant variability of DiGeorge syndrome, the type and severity of symptoms are typically determined by the organ system affected.
DiGeorge syndrome can become evident at birth, in infancy or during early childhood.1
Diagnosis of DiGeorge syndrome
DiGeorge syndrome is most commonly diagnosed with a blood test called a FISH analysis (Fluorescent In Situ Hybridization).1,2
A health care provider is likely to request a FISH analysis if a child presents with symptoms indicative of DiGeorge syndrome, or if a child has a heart defect – certain types of heart defect are strongly associated with the condition.
Treatment for DiGeorge syndrome
Treatment of the condition is dependent on the organ systems involved and may require coordination of care with many members of the health care community.1,2
Treating DiGeorge syndrome often requires coordinating care between a variety of different health specialists.
A child’s coordination of care may involve any number of the following health care professionals:1
- Infectious disease specialists
- Therapists (occupational, physical, speech, developmental and mental).
Different conditions caused by DiGeorge syndrome require different approaches to treatment, including the following:1,2
- Hypoparathyroidism: treatments to address hypoparathyroidism may include supplementation with vitamin D or calcium as well as supplementation with parathyroid hormone
- Thymus gland function:
- Limited thymus gland function may affect the ability of an individual with DiGeorge syndrome to fight infection, and frequent infections may be common, however mild or moderate in nature. Treatment and vaccine scheduling for these children is typically the same as for their unaffected peers, and their immune function will typically improve as they get older.
- Severe thymus dysfunction places a child with DiGeorge syndrome at risk for severe infections, and they may need to undergo thymus tissue transplantation, bone marrow transplant, stem cell transplant or transplant of disease-fighting blood cells.
- Cleft palate: surgical repair
- Heart defects: most typically addressed with surgical repair
- Development: when addressing the overall development of a child with DiGeorge syndrome, a multitude of therapists will be consulted (see above)
- Mental health care: treatment of certain mental health disorders may require treatment depending on the diagnosis that is made.
Prognosis of DiGeorge syndrome
Currently, there is no cure for DiGeorge syndrome. Prognosis for those affected with DiGeorge syndrome is dependent on the organ system affected and the severity of the condition. As with most medical conditions, early diagnosis and treatment is essential.1,2
Speak with your health care provider if you think that your pregnancy may be at risk for developing DiGeorge syndrome or if your child is displaying symptoms of the condition.
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