DiGeorge syndrome, also called 22q11.2 deletion syndrome, is a disorder caused by a defect in chromosome 22. It results in the poor development of several body systems.
Medical problems commonly associated with DiGeorge syndrome include heart defects, poor immune system function, a cleft palate, complications related to low levels of calcium in the blood, and delayed development with behavioral and emotional problems.
The number and severity of symptoms associated with DiGeorge syndrome vary greatly. However, almost everyone with DiGeorge syndrome needs treatment from specialists in a variety of fields.
Before the discovery of the chromosome 22 defect, the disorder was known by several names — DiGeorge syndrome, velocardiofacial syndrome, Shprintzen syndrome, CATCH22 and others. Although the term "22q11.2 deletion syndrome" is frequently used today — and is generally a more accurate description — previous names for the disorder are still used.
Signs and symptoms of DiGeorge syndrome can vary significantly in type and severity, depending on what body systems are affected and how severe the defects are. Some signs and symptoms may be apparent at birth, but others may not appear until later in infancy or early childhood.
Signs and symptoms may include some combination of the following:
- Bluish skin due to poor circulation of oxygen-rich blood (cyanosis) as a result of a heart defect
- Breathing problems
- Twitching or spasms around the mouth, hands, arms or throat
- Frequent infections
- Certain facial features, such as an underdeveloped chin, low-set ears, wide-set eyes or a narrow groove in the upper lip
- A gap in the roof of the mouth (cleft palate) or other problems with the palate
- Delayed growth
- Difficulty feeding and gastrointestinal problems
- Failure to gain weight
- Poor muscle tone
- Delayed development, such as delays in rolling over, sitting up or other infant milestones
- Delayed speech development
- Learning delays or difficulties and behavior problems
When to see a doctor
Other conditions may cause the signs and symptoms of DiGeorge syndrome. So it's important to get an accurate and prompt diagnosis if your child shows any signs or symptoms of the disorder.
If your child has any of the signs and symptoms above, seek immediate medical care.
DiGeorge syndrome is caused by the deletion of a portion of chromosome 22. Each person has two copies of chromosome 22, one inherited from each parent.
If a person has DiGeorge syndrome, one copy of chromosome 22 is missing a segment that includes an estimated 30 to 40 genes. Many of these genes haven't been clearly identified and aren't well-understood. The region of chromosome 22 that's deleted in DiGeorge syndrome is known as 22q11.2.
The deletion of genes from chromosome 22 usually occurs as a random event in the father's sperm or in the mother's egg, or it may occur early during fetal development. Rarely, the deletion is an inherited condition passed to a child from a parent who also has deletions in chromosome 22 but may or may not have symptoms.
The portions of chromosome 22 deleted in DiGeorge syndrome play a role in the development of a number of body systems. As a result, the disorder can cause several errors during fetal development. Common problems that occur with DiGeorge syndrome include:
- Heart defects. DiGeorge syndrome often causes heart defects that result in an insufficient supply of oxygen-rich blood. These defects may include a hole between the lower chambers of the heart (ventricular septal defect); only one large vessel, rather than two vessels, leading out of the heart (truncus arteriosus); or a combination of four abnormal heart structures (tetralogy of Fallot).
- Hypoparathyroidism. The four parathyroid glands in your neck regulate the levels of calcium and phosphorus in your body. DiGeorge syndrome can cause smaller than normal parathyroid glands that secrete too little parathyroid hormone (PTH), leading to a condition called hypoparathyroidism. This condition results in low levels of calcium and high levels of phosphorus in your blood.
- Thymus gland dysfunction. The thymus gland, located beneath the breastbone, is where T cells — a type of white blood cell — mature. Mature T cells are needed to help fight infections. In children with DiGeorge syndrome, the thymus gland may be small or missing, resulting in poor immune function and frequent, severe infections.
- Cleft palate. A common condition of DiGeorge syndrome is a cleft palate — an opening (cleft) in the roof of the mouth (palate) — with or without a cleft lip. Other, less visible abnormalities of the palate that may also be present can make it difficult to swallow or produce certain sounds in speech.
- Distinct facial features. A number of particular facial features may be present in some people with DiGeorge syndrome. These may include small, low-set ears, wide-set eyes, hooded eyes, a relatively long face, or a short or flattened groove in the upper lip.
- Learning, behavioral and mental health problems. The 22q11.2 deletion may cause problems with the development and function of the brain, resulting in learning, social, developmental or behavioral problems. Delays in toddler speech development and learning difficulties are common. A number of children with DiGeorge syndrome develop attention-deficit/hyperactivity disorder (ADHD) or autism spectrum disorder. Later in life people with DiGeorge syndrome are at increased risk of depression, anxiety disorders, schizophrenia and other mental health disorders.
- Autoimmune disorders. People who had poor immune function as children, due to a small or missing thymus, may have an increased risk of autoimmune disorders, such as rheumatoid arthritis or Graves' disease.
- Other problems. A large number of medical conditions may be associated with DiGeorge syndrome, such as hearing impairment, poor vision, poor kidney function, and relatively short stature for one's family.
DiGeorge syndrome may be suspected:
- At birth. If certain conditions — a severe heart defect, cleft palate or a combination of other factors typical of DiGeorge syndrome — are readily apparent at birth, diagnostic tests will likely begin before your child leaves the hospital.
- At well-baby visits. Your family doctor or pediatrician may suspect the disorder because of a combination of illnesses or disorders that become apparent over time. Other issues may come to the attention of your doctor during regularly scheduled well-baby visits or annual checkups for your child.
Well-baby visits and annual checkups
It's important to take your child to all regularly scheduled well-baby visits and annual appointments. These visits can help identify early signs of developmental delays and give you the opportunity to discuss any concerns with your doctor.
Be prepared to answer questions that your child's doctor may ask, such as:
- Does your baby have any problems feeding?
- Does your baby seem listless, weak or sick?
- Is your child reaching certain milestones in development, such as rolling over, pushing up, sitting up, crawling, walking or speaking?
- Do you observe any behaviors that concern you?
Talking to your doctor about DiGeorge syndrome
If your family doctor or pediatrician believes that your child shows signs or symptoms of DiGeorge syndrome and suggests diagnostic tests, you may want to discuss these questions:
- What diagnostic tests will be needed?
- When will we know and how will we get the results of the tests?
- What specialists will you refer us to?
- What medical conditions related to DiGeorge syndrome need to be addressed right now? What is our highest priority?
- How will you help me monitor my child's health and development?
- Can you suggest educational materials and local support services regarding DiGeorge syndrome?
- What services are available for early childhood development?
A diagnosis of DiGeorge syndrome is based primarily on a lab test that can detect the deletion in chromosome 22. Your doctor will likely order such a test if your child has:
- A combination of medical problems or conditions suggesting DiGeorge syndrome
- A heart defect, because certain heart defects are commonly associated with DiGeorge syndrome
In some cases, a child may have a combination of conditions that suggest DiGeorge syndrome, but the lab test doesn't indicate a deletion in chromosome 22. Although these cases present a diagnostic challenge, the coordination of care to address all of the medical, developmental or behavioral problems will likely be similar.
Health care team
Because DiGeorge syndrome can result in so many problems, a number of specialists will likely be involved in diagnosing specific conditions, recommending treatments and providing care. This team will evolve as your child's needs change. Specialists in your care team may include these professionals, as needed:
- Children's health specialist (pediatrician)
- Expert in inherited disorders (geneticist)
- Heart specialist (cardiologist)
- Immune system specialist (immunologist)
- Infectious disease specialist
- Hormone disorder specialist (endocrinologist)
- Surgeon who specializes in correcting such conditions as a cleft palate (oral and maxillofacial surgeon)
- Surgeon who specializes in correcting heart defects (cardiovascular surgeon)
- Other surgical specialists
- Therapist who helps your child develop practical, everyday skills (occupational therapist)
- Therapist who helps your child improve verbal skills and articulation (speech therapist)
- Therapist who helps your child develop age-appropriate behaviors, social skills and interpersonal skills (developmental therapist)
- Mental health professional, such as a pediatric psychologist or psychiatrist
Although there is no cure for DiGeorge syndrome, treatments can usually correct critical problems, such as a heart defect or low calcium levels. Other health issues and developmental, mental health or behavioral problems can be addressed or monitored as needed.
Treatments and therapy for DiGeorge syndrome may include interventions for:
- Hypoparathyroidism. Hypoparathyroidism can usually be managed with calcium supplements and vitamin D supplements.
- Limited thymus gland function. If your child has some thymic function, infections may be frequent, but not necessarily severe. These infections — usually colds and ear infections — are generally treated as they would be in any child. Most children with limited thymic function follow the normal schedule of vaccines. For most children with moderate thymus impairment, immune system function improves with age.
- Severe thymus dysfunction. If the impairment of the thymus is severe or there's no thymus, your child is at risk of a number of severe infections. Treatment requires a transplant of thymus tissue, specialized cells from bone marrow or specialized disease-fighting blood cells.
- Cleft palate. A cleft palate or other abnormalities of the palate and lip can usually be surgically repaired.
- Heart defects. Most heart defects associated with DiGeorge syndrome require surgery to repair the heart and improve the supply of oxygen-rich blood.
- Overall development. Your child will likely benefit from a range of therapies, including speech therapy, occupational therapy and developmental therapy. In the United States, early intervention programs providing these types of therapy are usually available through a state or county health department.
- Mental health care. Treatment may be recommended if your child is later diagnosed with attention-deficit/hyperactivity disorder (ADHD), depression, schizophrenia, or other mental health or behavioral disorders.
Having a child with DiGeorge syndrome is challenging. You must deal with numerous treatment issues, manage your own expectations and meet the needs of your child. Organizations such as the Velo-Cardio-Facial Syndrome Educational Foundation provide educational materials, support groups and other resources for parents of children with DiGeorge syndrome.
In some cases, DiGeorge syndrome may be passed from an affected parent to a child. If you're concerned about a family history of DiGeorge syndrome, or if you already have a child with DiGeorge syndrome, you may want to consult a doctor who specializes in genetic disorders (geneticist) or a genetic counselor for help in planning future pregnancies.