With appropriate treatment, most children with DiGeorge syndrome grow into adulthood; however, children with severe defects may not survive beyond two to three years.
The life expectancy of people with DiGeorge syndrome varies depending on the severity of the condition and the treatment provided. With appropriate treatment, most children grow into adulthood.
Surgical intervention may be required to treat congenital issues, such as heart defects. Children with severe heart defects and immune system problems may not survive beyond their second or third birthday.
Children who survive into adulthood need long-term follow-up and medical care.
- Affected children may require extra support at school or work.
- They may need long-term care for psychological issues, such as autism, attention deficit hyperactivity disorder, anxiety, and obsessive-compulsive disorder.
Apart from heart problems, low immunity may pose a significant threat to life. Frequent infections may often become life-threatening. Thus, regular follow-up and care are essential for the person to live a productive, long, and fulfilling life.
What is DiGeorge syndrome?
DiGeorge syndrome also called 22q.11 deletion syndrome or velocardiofacial syndrome, is a congenital (present since birth) condition.
- The condition may affect several body sites due to a genetic defect called deletion on the long arm (called “q” arm) of chromosome number 22.
- There are 23 pairs of chromosomes in each cell of the body.
- Of these, 22 pairs are called autosomes, whereas one pair is of the sex chromosomes.
It is a rare disorder that affects about 1 in 4000 to 6000 live pregnancies. The condition may be passed on from a parent to their baby as seen in about 1 in 10 families. Thus, the affected person may get their genetic counseling and testing done to find out the likelihood of transferring the condition to their future children.
DiGeorge syndrome (DGS) is classified as a primary immunodeficiency disease. This means that the affected people have defective immune systems leading to increased susceptibilities to various diseases.
- The cause of immunodeficiency in DiGeorge syndrome is a poorly developed or absent thymus, the organ that programs a type of immune cells (called T-cells) to effectively fight infections.
- The thymus equips the T-cells to differentiate between body tissues (self) and harmful agents, such as bacteria and viruses (nonself). This mechanism prevents the attack of the body tissues by the T-cells (autoimmunity).
The abnormal cell and tissue development in DiGeorge syndrome affect different body organs, including the heart, bones (particularly facial bones), thyroid gland, kidneys, gut, and parathyroid gland. These developmental abnormalities start in the fetus and are generally present during infancy or early childhood.
What are the symptoms of DiGeorge syndrome?
The symptoms of DiGeorge syndrome and their severity may vary with people.
The syndrome can affect various organs and organ systems, leading to different signs and symptoms including:
- Immunodeficiency:
- The affected person may have varying degrees of immunodeficiency.
- People with complete DiGeorge syndrome have absent thymus that makes them extremely susceptible to infections. A thymus transplant is required for survival in such cases.
- Immunodeficiency often leads to frequent respiratory infections, which cause breathing difficulties. It makes the person prone to infections with microorganisms that are generally harmless to people with a healthy immune system.
- Complete DiGeorge syndrome is seen in less than one percent of the affected people. The majority have partial DiGeorge syndrome, where the thymic activity is insufficient but not absent. Such infants have recurrent infections, but the immunity tends to improve as they grow.
- Cardiac abnormalities:
- Heart defects may be seen in the affected babies, which may be diagnosed by a heart murmur on medical examination.
- The baby may present with bluish discoloration of the skin (cyanosis) due to a reduced supply of oxygen-rich blood.
- The severity and time of presentation of the symptoms may vary depending on the type of cardiac abnormality.
- Abnormal blood vessels may cause pressure on the esophagus or trachea, leading to feeding and breathing difficulties. The affected infant may present with poor feeding and inability to gain weight (failure to thrive).
- Cranio-facial structure defects:
- Defects in the development of the facial bones may cause structural defects. The affected person may have typical facial features, such as the elongated face, prominent nose, short philtrum (the vertical groove between the lower part of the nose and the upper lip) and cleft palate (a gap in the roof of the mouth), and small jaw (micrognathia).
- There may be other signs as well, such as a small skull (microcephaly), asymmetric crying face, and a dimple on the nose.
- The craniofacial defects may cause problems, such as feeding difficulties, the nasal tone in the voice (hypernasality), speech problems, and hearing loss.
- Hypocalcemia:
- Low calcium levels or hypocalcemia is a major problem in DiGeorge syndrome. It is seen in about 17 to 60 percent of the affected individuals.
- Low calcium levels may cause seizures and require calcium supplementation.
- The condition improves on its own, and about 50 percent of the affected individuals do not require calcium supplementation by the time they reach their first birthday.
- Spine abnormalities:
- Feeding problems:
- Feeding issues may be seen in about 36 percent of the affected people.
- The baby may have problems, such as poor sucking or regurgitation of the feeds and vomiting.
- Feeding issues are generally caused by defective development of the throat (pharynx) and palate.
- Poor feeding may result from abnormal blood vessels, (vascular rings) compressing the esophagus.
- Hormonal problems:
- DiGeorge syndrome is often associated with defective functioning of the parathyroid gland. This may lead to low calcium and high phosphorus levels in the blood.
- Low calcium levels may cause problems, such as jitteriness, abnormal spasms (tetany), and seizures.
There may be other problems as well, such as:
- Learning difficulties
- Obsessive-compulsive disorder
- Autism
- Constipation
- Frequent ear infections
- Hearing loss
- Hooded eyelids
- Small ears
- Clubfeet
- Hernias
- Delayed milestones in infants
- Kidney abnormalities
- Skin rash
- Poor growth
- Enlarged lymph nodes or glands
- Lung abnormalities
- Increased risk of certain cancers, such as hepatoblastoma (a type of liver cancer) and some kidney cancers (such as Wilms’ tumor and renal cell carcinoma)