22q11.2 deletion syndrome

22q11.2 deletion syndrome is a genetic difference that is linked with over 180 different health issues. Over the years, it has been called by many names including DiGeorge syndrome, Velocardiofacial syndrome, Shprintzen syndrome and Conotruncal anomaly face syndrome. Now it is referred to as 22q11.2 deletion syndrome since all of these syndromes have the same underlying cause – the 22q11.2 deletion chromosome.

Causes

Most people have 23 pairs of chromosomes in their bodies for a total of 46. Chromosomes are made up of many smaller structures which are our genes. (Genes determine the characteristics or traits that pass from a parent to a child.) Chromosomes are numbered from one to 22. (The 23rd pair are actually the ones which tell whether we are male or female and are called X and Y). All human chromosomes have two segments called arms.

Children with 22q11.2 deletion syndrome are missing a small piece of their 22nd chromosome, which is why it is called a “deletion.” The q11.2 is the missing piece of the chromosome. It tells researchers that there is a missing piece on the long arm, known as the q arm, of chromosome 22.

Most children with 22q11.2 deletion syndrome don’t have a parent with the same problem; only 10 percent, or one in 10, of parents who have a child with this condition have the same chromosomal difference. This means most children are the first in their families to have this deletion. Parents with a child with 22q11.2 deletion syndrome should have a blood test to see if they have this difference and to find out their chances of having other children with the same syndrome. If a child has a diagnosis of 22q11.2 deletion syndrome, there is a 50 percent chance it will be passed on to their children.

22q11.2 deletion syndrome is present in one out of every 2,000-4,000 live births, in one in 68 children born with heart disease, and in 5 to 8 percent of children born with a cleft palate.

Signs/symptoms

22q11.2 deletion syndrome may involve many different systems of the body. There are a wide range of health issues which have been linked to this chromosomal difference. Every child is different, some children have more problems than others. Some of the most common affected areas are listed below.

Heart defects are usually discovered the earliest and may include:

• A hole in the heart’s chamber wall
• Blockage of blood leaving the heart
• Problems with the blood vessels coming out of the heart
• A combination of abnormalities of the heart’s structure and how it works

Palate problems related to the mouth may include:

• Cleft palate
• Cleft lip and palate
• Submucous cleft palate (condition where the muscles of the roof of the mouth are not joined together properly)   
• Velopharyngeal dysfunction, or VPI (too much air escapes from the nose during talking and speech sounds nasal).

Feeding and eating difficulties may include:

• Vomiting
• Nasal regurgitation (food/fluids leak out the nose caused by a problem with the roof of the mouth, or palate)
• Gastroesophageal reflux, or GERD (stomach contents flow back into the throat)

Stomach problems may include:

• Constipation
• Hernias in organs of the digestive tract
• Twisting of the tubes of the intestine

Ear, nose and throat problems may include:

• Abnormal connections between the throat and the tube leading to the lungs
• Vocal cord structure abnormalities
• Differences in the shape of the ear

Bone and muscle issues may include: 

• Scoliosis
• Club feet
• Spine abnormalities

Endocrine system issues may include: 

• Problems with low calcium in newborns
• Growth problems associated with not having enough growth hormones

Development/learning/behavior may be affected. Children may have:

• Delays in speech, language, cognition (thinking/reasoning/memory) or motor skills (These differences in learning styles may require extra help in school.)
• Autism and psychiatric disorders including schizophrenia, ADHD or obsessive-compulsive behaviors

Immune system problems may include:

• Repeated ear infections
• Wound infections/poor healing
• Respiratory (lung) infections
• Autoimmune diseases (conditions involving immune system mistakenly attacking normal body tissues)

Diagnosis and treatment

If your child’s pediatrician or specialist thinks there may be a chromosomal problem, your child will be referred for testing. A blood test called FISH (fluorescence in situ hybridization) or a test that analyzes chromosomes will help to diagnose this syndrome. We recommended that all children with a cleft palate have this test along with a genetics evaluation.

The team members at our Center for Craniofacial Care are experienced in treating children with 22q11.2 deletion syndrome. Our specialists work together to develop an individualized treatment plan and will help connect children and families with the additional specialists and resources they may need.