DiGeorge Syndrome

DiGeorge syndrome is a congenital genetic condition marked by incomplete development of numerous body systems. It is caused due to deletion of a section of chromosome 22 and hence is medically referred to as 22q11.2 deletion syndrome.

Before the discovery of chromosome 22 defect as the causative factor, DiGeorge syndrome was referred to by several different names, including velocardiofacial syndrome, etc. The medical name may offer the most apt description of the condition and is the most used by medical professionals, but the other names are also still in circulation.

DiGeorge syndrome patients may experience diverse developmental problems and disorders, including behavioral problems, cardiac disorders, immune system dysfunctions, cleft palate, and low calcium levels.

The severity of DiGeorge syndrome and the count of additional conditions that accompany the genetic disorder varies from one patient to another. Most cases require treatment by specialists from varied fields of medical expertise.

Symptoms

The signs and symptoms of DiGeorge syndrome vary from person to person with regards to type and severity. Such variation is dependent on the count of the body systems that are affected as well as the severity of such problems. A few symptoms may be evident at the time of birth, while others may develop over time during infancy or early childhood. A few common symptoms are listed below:

• Delayed development, including delays in achieving developmental milestones such as sitting upright, rolling over, walking, or crawling.
• Deficient flow of oxygen-rich blood throughout the body. This can result in cyanosis, a condition marked by bluish tinge of the skin.
• Varied areas of the body, including the hands, arms, mouth, throat, face, etc., may elicit ticks or spasms.
• Presence of widely-set or hooded eyes, a flattened and elongated face, low-set or droopy ears, short or thin grove on the upper lip, and other distinctive facial features.
• Weakness, lethargy, and easy fatigue
• Cleft palate and other palate abnormalities.
• Delayed development of speech
• Lack of gain in weight
• Poor muscle mass and muscle tone
• Breathlessness and other respiratory and breathing problems
• Failure to thrive and flourish
• Feeding difficulties
• Learning delays and problems
• Increased cases of infections
• Additionally, adult patients may be shorter as compared to other family members.

Defects of varied body systems associated with DiGeorge syndrome can trigger the onset of many different health complications such as heart disorders, hypoparathyroidism, thymus gland malfunction, vision anomalies, behavioral disorders, mental health issues, learning disabilities, a compromised immune system, hearing issues, autoimmune diseases, and kidney dysfunction.

Causes of DiGeorge syndrome

DiGeorge syndrome is a hereditary condition caused due to deletion or absence of a section part of chromosome 22. This chromosome houses an estimated 500 to 800 genes. Doctors refer to the deleted part of chromosome 22 as 22q11.2. In some patients, a smaller section of chromosome 22 is found to be missing.

Every human child inherits two copies of chromosome 22; one copy is passed by the mother and the other copy is inherited from the father. In people with DiGeorge syndrome, one of the copies of chromosome 22 does not contain a specific (22q11.2) part. This section is home to about 30 to 40 genes. A majority of these genes are yet to be identified; medical experts are also unaware of their functions.

The genetic error or deletion of a part of chromosome 22 occurs at random, at the time of sperm or egg development or during the initial phases of conception. This is the reason why the chromosomal abnormality gets replicated in nearly all the cells during fetal formation and growth.

Treatment

Currently, there is no way in which genetic abnormalities can be corrected. Hence, DiGeorge syndrome has no known cure. Treatment of DiGeorge syndrome is aimed at managing the symptoms and preventing the onset of health complications.

A few common treatment options are listed below:

• Limited functioning of the thymus gland comes with increased risk to development of mild infections such as colds and chronic ear infections. It is treated with OTC and prescription antibiotics and other medications.
  • Children with compromised thymic functionality need to go for the normal course of vaccines to help the immune system. It may be noted that as affected children grow older, the immune system naturally becomes stronger.
  • Absence of the thymus gland or severe thymic dysfunction may increase the risk to severe and numerous infections. It is treated via transplantation of certain blood cells or thymus tissue obtained from the bone marrow. This helps fight varied diseases.
    • Patients of DiGeorge syndrome may also require medications to manage the immune system for the remainder of their lives.
    • Consumption of vitamin D and calcium supplements as well as limiting the intake of phosphorus can help alleviate the symptoms of hypoparathyroidism. In cases where an adequate section of the parathyroid gland has remained intact, then as the affected child grows older, the gland will consequently be able to control the levels of calcium on its own without the help of special diets.
    • Varied physical defects such as cardiac anomalies, cleft palate, etc., can be corrected via surgery. Hearing aids can help overcome problems with the ear.
    • Different kinds of social, language, emotional, and behavioral problems can be remedied via diverse therapies such as speech therapy, occupational therapy, counseling, psychotherapy, and behavioral therapy, etc.
      • It may be noted that alleviation of developmental, mental health, and behavioral disorders is quite problematic. The prognosis is also less predictable.
      • Hormonal supplements can help alleviate thyroid problems.

DiGeorge syndrome life expectancy

DiGeorge syndrome life expectancy and prognosis is dependent on the number of body systems that are affected and the severity of such problems. Advances in medical care and health services has allowed DiGeorge syndrome patients to have a normal life expectancy with some form of dependency during their lifetime.

Varied statistics and studies have indicated that nearly 20 percent of DiGeorge syndrome patients tend to die during the first 12 months after birth. Most deaths occur due to cardiac problems and sepsis, the latter of which occurs due to severe immunodeficiency and subsequent bacterial or fungal infections. DiGeorge syndrome affected children who successfully overcome the difficulties during the first year of life generally tend to develop normally with some level of learning deficits.

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