DiGeorge Syndrome: Causes, Symptoms, Diagnosis, Treatment, and Prevention
A rare genetic disorder, DiGeorge syndrome affects the development of several body systems as a result of a missing region of chromosome 22, which contains many genes essential for normal growth and function. Symptoms of DiGeorge syndrome range from mild to severe, depending on the size and location of the deletion and the genes involved. Some of the common symptoms include:
Symptoms of DiGeorge Syndrome
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Congenital heart defects: DiGeorge syndrome patients often have defects of the heart that are present at birth. These can affect the blood flow and oxygen delivery to the body, and may require surgery or medication to correct. Examples of heart defects include heart murmurs, ventricular septal defects, and tetralogy of Fallot.
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Cleft palate or lip: A cleft palate or lip is a split or gap in the roof of the mouth or upper lip that can affect feeding, speech, and dental health. Cleft palates and lips can usually be repaired with surgery when they are young.
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It is common for people with DiGeorge syndrome to have low calcium levels in their blood, which can cause muscle spasms, seizures, and abnormal heart rhythms. It is caused by a lack of parathyroid glands, which control calcium levels. Calcium supplements and vitamin D may be needed to treat this condition.
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The immune system can be affected by DiGeorge syndrome in the way the thymus gland develops and functions, which produces T-cells, white blood cells that fight infections. A person with DiGeorge syndrome may have a reduced number of T-cells, resulting in infections and autoimmune diseases. These problems can be prevented or treated with antibiotics, vaccines, or bone marrow transplants.
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Learning disabilities and developmental delays: Children with DiGeorge syndrome may have difficulties reaching developmental milestones, including sitting, walking, talking, and learning. In addition to speech, language, memory, attention, and social skills difficulties, people with DiGeorge syndrome may also suffer from behavioral problems such as ADHD, autism, anxiety, or depression. Those challenges can be addressed with special education, speech therapy, or psychotherapy.
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DiGeorge syndrome can also cause kidney abnormalities, hearing loss, skeletal malformations, short stature, and facial features, such as wide-set eyes, narrow eyelids, underdeveloped chins, low-set ears, and broad noses.
Causes of DiGeorge Syndrome
A deletion of a small section of chromosome 22, called 22q11.2, causes DiGeorge syndrome. Each person has two copies of each chromosome, one from each parent. Chromosomes contain our genetic information. 22q11.2 deletions can occur randomly during the formation of eggs or sperm, or they can be inherited from parents who have the same deletion. Genes involved in the development of various body systems can be affected by the deletion, which can vary in size and location.
Diagnosis of DiGeorge Syndrome
It is possible to diagnose DiGeorge syndrome based on symptoms, a physical exam, and genetic testing. By using fluorescence in situ hybridization (FISH) or array comparative genomic hybridization (aCGH), genetic testing can confirm the deletion of 22q11.2. Additionally, the heart, kidneys, parathyroid glands, thymus glands, and immune system may be tested.
Treatment of DiGeorge Syndrome
There is no cure for DiGeorge syndrome, but treatments can help manage the symptoms and improve quality of life. Treatment depends on the type and severity of symptoms, and may involve a team of specialists, such as cardiologists, endocrinologists, immunologists, surgeons, dentists, audiologists, nephrologists, neurologists, psychologists, and educators. There are several possible treatments:
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Heart surgery or medication: To correct or improve the heart defects and prevent complications.
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Cleft palate or lip repair: To improve feeding, speech, and dental health.
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Calcium and vitamin D supplements: To prevent or treat low calcium levels and related problems.
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Antibiotics, vaccines, and bone marrow transplantation: To prevent or treat infections and immune system problems.
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Special education, speech therapy, and psychotherapy: To help with developmental delays, learning disabilities, and behavioral problems.
Prevention of DiGeorge Syndrome
There is no way to prevent DiGeorge syndrome, as it is a genetic disorder that occurs randomly or is inherited. However, some steps that may reduce the risk of having a child with DiGeorge syndrome are:
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You may benefit from genetic counseling and testing if you or your partner have a family history of DiGeorge syndrome or if you have a child with DiGeorge syndrome. To determine if your children will inherit the deletion of 22q11.2, genetic counseling and testing may be helpful. If you want to detect the deletion in your unborn child, you may also consider prenatal testing, such as amniocentesis or chorionic villus sampling.
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When you take folic acid during pregnancy and before you become pregnant, you may reduce your child's risk of developing cleft palates and lips. The neural tube, which forms the brain and spinal cord, is formed by folic acid, a vitamin. For pregnant women or women planning to become pregnant, 400 micrograms of folic acid per day is recommended.
