Digeorge Syndrome

1 What is DiGeorge Syndrome?

DiGeorge syndrome is a disorder caused by a defect in chromosome 22. This leads to poor development of several systems in the body.

Medical problems associated with DiGeorge syndrome include

  • heart defects,
  • poor immune system function,
  • cleft palate,
  • complications related to low levels of calcium in the blood and delayed development with behaviora;
  • and emotional problems.

The number and severity of symptoms of DiGerge syndrome vary greatly. Before the chromosome 22 defect was discovered, this disorder was known as Digeorge syndrome, velocardiofacial syndrome, Shprintzen syndrome, CATCH22 and others.

2 Symptoms

The signs and symptoms of DiGeorge syndrome depend on which body systems are affected. Some signs and symptoms may be present at birth while others may appear later in infancy or childhood.

The signs and symptoms may include the following combinations:

  • Bluish skin due to poor circulation of oxygen-rich blood as a result of a heart defect
  • Breathing problems
  • Twitching or spasms around the mouth, hands, arms or throat
  • Frequent infections
  • Certain changes in the facial features, such as underdeveloped chin, low-set ears, wide-set eyes or a narrow groove in the upper lip
  • Cleft palate ( gap in the roof of the mouth) or other problems with the palate
  • Delayed physical growth
  • Difficulty feeding and gastrointestinal problems
  • Delayed development, such as delays in rolling over, sitting up or other infant milestones
  • Delayed speech development
  • Learning delays or difficulties and behavioral problems                                                                                                                                                                                            

3 Causes

DiGeorge syndrome is caused by the deletion of part of chromosome 22. Each person has two copies of chromosome 22, one inherited from each parent. One copy of chromosome 22 has a deleted portion in people with DiGeorge syndrome.

The region of of chromosome 22 that is deleted in DiGeorge syndrome is called 22q11.2. Approximately 30 to 40 genes are deleted. The deletion can occur either in the father's sperm or mother's egg or may even occur during early fetal development.

Some times this deletion can be passed from parents to children. However, this occurs rarely and individuals may  or may not have any symptoms.

4 Making a Diagnosis

The diagnosis of DiGEorge syndrome is based on identifying the deletion in chromosome 22 using lab tests.

This is usually done when a child has a combination of medical problems or conditions suggesting DiGEorge syndrome and a heart defect, since heart defects are commonly associated with DiGeorge syndrome.                                                                                                                                                                                                                                               

5 Treatment

There is no cure for DiGeorge syndrome, however, there are treatments that can correct critical problems, such as defects in the heart or low calcium levels. Mental health and behavioral problems can be addressed or monitored as needed.

Treatments and therapy for DiGeorge syndrome may include:

  • Children with limited thymus function are recommended to follow the normal vaccination schedule.
  • Children with severe thymus dysfunction may be given a transplant of thymus tissue, specialized cells from the bone marrow or specialized disease-fighting blood cells.
  • Cleft palate and other problems with the palate can be surgically corrected.
  • Heart defetcs require surgery to repair of the heart  and improve the supply of oxygen-rich blood.
  • Speech therapy, occupational therapy and development therapy are required for overall develpment of a child with DiGeorge syndrome.
  • Mental health care may be recommended if a child is later diagnosed with attention deficit/hyperactivity disorder (ADHD), depression, schizophrenia or other mental health or behavioral disorders.                                                                             

6 Prevention

There are no current guidelines to prevent DiGeorge syndrome.

In some cases, DiGeorge syndrome can be inhereted. Therefore, people with a familiy history of DiGeorge syndrome or parents who already have a child with this diasese can consult a genetic specialist for help in planning future pregnancies.

7 Lifestyle and Coping

When diagnosed with DiGeorge syndrome, it might be hard for your children to cope and develop a normal lifestyle.

Organizations such as Velo-Cardio-Facial Syndrome Educational Foundation provide educational materials, support groups and other resources for parents with children with Digeorge syndrome. 

8 Risks and Complications

There are several risks and complications associated with DiGeorge syndrome.

The deletion of a portion of chromosome 22 can lead to several errors during fetal development.

Common problems that can occur as a result of this disease include:

  • Heart defects including a hole between the lower chamber of the heart (ventricular septal defect), only one enlarged vessel, rather than two esesls, leading out of the heart (truncus arteriosus) or a combination of four abnormal heart structures (tetralogy of Fallot). These conditions can result in insufficient supply of oxygen-rich blood.
  • Hypothyroidism due to smaller than normal parathyroid glands that secrete little amounts of parathyroid hormone. This leads to a decrease in the level of calcium and an increase in phosphorus levels in the blood.                        
  • Thyroid glan dysfunctions due to a smaller than normal or absent thymus. This leads to a poor immune system and frequent and severe infections.
  • A cleft palate - an opening in the roof of the mouth, with or without a cleft lip. Other less visible abnormalities of the palte can make it difficult to swallow nad produce certain sounds in speech.
  • Distinct facial features, such as 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 including attention deficit/hyperactivity disorder (ADHD) or autism spectrum disease, depression, anxiety disorders, schizophrenia. Mental health problems usually develop later in life.
  • Other problems may include hearing impairment, poor vision, poor kidney function and relatively short stature for one's family.