22q11.2 Deletion Syndrome
A tiny missing piece of chromosome 22, present from conception. It’s one of the most common genetic conditions, in about 1 in 2,000 babies, yet often missed for years because it looks so different from one person to the next. Earlier diagnosis means earlier checks for things that are very treatable.
What it is
- A small piece of chromosome 22 (at a spot called 22q11.2) is missing on one copy. It holds about 40 genes.
- It has had many names: DiGeorge syndrome, velocardiofacial syndrome (VCFS) and others. Different specialists described different parts of the same condition.
- About 90 to 95% of deletions are new, not inherited. A parent with the deletion has a 50% chance of passing it on in each pregnancy.
What it can affect
- Heart: about 3 in 4 children have a heart difference, such as tetralogy of Fallot, a hole in the heart or an unusual aortic arch.
- Palate and speech: about 3 in 4 have some palate difference. Most are subtle (like a hidden cleft), causing nasal-sounding speech or milk coming out of the nose.
- Calcium: about half have low calcium from small parathyroid glands. It can cause seizures in newborns and can come back at times of stress, like surgery, illness or pregnancy.
- Immunity: up to 3 in 4 children have a small thymus and fewer T cells, so more infections. Most improve with age; a few need specialist treatment.
- Learning: most have some learning difficulty. The average IQ is around 70, with a wide range; severe intellectual disability is uncommon.
- Mental health: anxiety, ADHD and autism are more common in childhood. About 1 in 4 adults develop schizophrenia, which responds to the usual treatments.
- Other: feeding problems, kidney differences, hearing loss, thyroid problems, scoliosis, seizures and, later, early Parkinson disease.
Signs that should prompt a test
- Certain heart defects, especially interrupted aortic arch, truncus arteriosus or tetralogy of Fallot.
- Low calcium or seizures in a newborn.
- Nasal speech, a cleft palate or milk coming out of the nose.
- Frequent infections with a low T-cell count (sometimes picked up on newborn screening).
- A child with several of these together, plus speech delay or learning difficulties.
- A parent of a child with the deletion: parents are offered testing too.
How it’s diagnosed
- A blood test called a chromosomal microarray finds the deletion. Older tests (FISH) are also used.
- It can be found in pregnancy with diagnostic testing, often after a heart difference is seen on an ultrasound.
- After diagnosis, a genetics service explains what it means for the person and the family.
Check-ups that help
- Heart check (echocardiogram) at diagnosis.
- Calcium and parathyroid hormone, at diagnosis and regularly, especially before surgery and during puberty or pregnancy.
- T-cell count before live vaccines (like MMR and chickenpox). Most children can have them once their count is checked.
- Thyroid tests, full blood count, a kidney ultrasound, and hearing and eye checks.
- Speech and palate review, development and school support, and mental health check-ins from childhood into adult life.
- One coordinating doctor, often a GP or paediatrician, keeps the whole picture together.
Living with 22q
- Many people with 22q11.2 deletion finish school, work, have relationships and raise families.
- Early speech therapy, school support and mental health care make a big difference.
- Watch for changes in thinking, mood or behaviour in teens and young adults, and seek help early.
- The International 22q11.2 Awareness Day is 22 November, chosen for chromosome 22.
Common questions
Is 22q11.2 deletion syndrome the same as DiGeorge syndrome?
Yes, mostly. DiGeorge syndrome was the first name, for babies with heart defects, low calcium and immune problems. Velocardiofacial syndrome described the palate and speech side. Most people with either diagnosis have the same 22q11.2 deletion.
How common is 22q11.2 deletion syndrome?
About 1 in 2,148 live births in a newborn screening study, and likely about 1 in 1,000 pregnancies. That makes it one of the most common genetic conditions.
Is it inherited?
Usually not: 90 to 95% of deletions are new. But a person with the deletion has a 50% chance of passing it on in each pregnancy, so genetic counselling is worthwhile.
Can people with 22q11.2 deletion have vaccines?
Most can have all routine vaccines. Live vaccines, like MMR and chickenpox, are given once a T-cell count shows the immune system can handle them.
Does everyone with 22q11.2 deletion get schizophrenia?
No. About 1 in 4 adults do, which is much higher than average, but most don’t. Knowing the risk means early signs can be picked up and treated.
Helpful resources
- International 22q11.2 FoundationInformation and family support. Free.
- Children’s Hospital of Philadelphia: 22q support groups worldwideFinds support groups, including in Australia and New Zealand. Free.
- Genetic Alliance AustraliaSupport for Australians with genetic conditions. Free.
Evidence and more information
- Óskarsdóttir S et al. Updated clinical practice recommendations for managing children with 22q11.2 deletion syndrome. Genet Med 2023
- Boot E et al. Updated clinical practice recommendations for managing adults with 22q11.2 deletion syndrome. Genet Med 2023
- McDonald-McGinn DM et al. 22q11.2 deletion syndrome. Nat Rev Dis Primers 2015
- Blagojevic C et al. Live-birth prevalence of 22q11.2 deletions from newborn screening. CMAJ Open 2021
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