DiGeorge syndrome
DEFINITION
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.
CAUSES
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.
SYMPTOMS
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.
