DiGeorge Syndrome

(Velocardiofacial Syndrome; Chromosome 22q11 Deletion Syndrome)

Definition

DiGeorge syndrome is a rare genetic disease present at birth and is associated with recurrent infection, heart defects, and characteristic facial features (see below). People with complete DiGeorge syndrome have no thymus or parathyroid glands.

Thyroid and Parathyroid Glands

Causes

DiGeorge syndrome is caused by a deletion of several genes from chromosome 22. Genes are blueprints for the body's development. The material lost in the deletion is required for the normal development of the thymus and related glands.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. Maternal diabetes is thought to increase the risk of DiGeorge syndrome.

Symptoms

Features of DiGeorge syndrome are present at birth and do not worsen with age. Features may include:

Immune deficiency leading to increased infections
Cleft palate]]>
Heart defects
]]>Failure-to-thrive]]>
Small head
Increased incidence of psychiatric disorders
Characteristic facial features, including elongated face, almond-shaped eyes, wide nose, small ears
Learning difficulties
]]>Hypoparathyroidism]]> —a disorder in which insufficient parathyroid hormone is secreted from the parathyroid glands, resulting in abnormally low levels of calcium in the blood
Weak muscles
Short height
Occasional abnormalities include structural brain defects, ]]>scoliosis]]> , umbilical or inguinal ]]>hernias]]> , kidney abnormalities, anogenital abnormalities, eye abnormalities, and thyroid problems
Tapered and hyperextensible fingers

Diagnosis

Your doctor will ask about symptoms and medical history, and perform a physical exam. Other tests may include:

Blood tests—to rule out other conditions, detect parathyroid hormone levels, and discover immune problems
Genetic tests—to look for deletions in chromosome 22
Chest x-ray]]> —a test that uses radiation to take pictures of structures inside the body, especially to determine if the thymus is present

Treatment

Talk with your doctor about the best treatment plan. In infants, thymic tissue transplantation or bone marrow transplantation]]> may help restore immune function, but the risks and benefits of these procedures must be carefully considered.

Prevention

There is no known way to prevent DiGeorge syndrome.

RESOURCES:

Immune Deficiency Foundation
http://www.primaryimmune.org

National Center for Biotechnology Information
http://www.ncbi.nlm.nih.gov

CANADIAN RESOURCES:

Canadian Directory of Genetic Support Groups
http://www.lhsc.on.ca/programs/medgenet/c_sup.htm

Health Canada
http://www.hc-sc.gc.ca/index_e.html

References:

DiGeorge syndrome. DynaMed website. Available at: http://dynamed101.ebscohost.com/Detail.aspx?id=115146 . Accessed May 23, 2007.

DiGeorge syndrome. National Center for Biotechnology Information website. Available at: http://www.ncbi.nlm.nih.gov/disease/DGS.html . Accessed May 23, 2007.

Jones KL. Smith’s Recognizable Patterns of Human Malformations , 6th ed. Elsevier Saunders: Philadelphia PA; 2006.

Kleigman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics . 18th ed. Saunders: Philadelphia PA; 2007.

Velocardiofacial syndrome. National Institute on Deafness and Other Communication Disorders website. Available at: http://www.nidcd.nih.gov/health/voice/velocario.asp . Accessed May 23, 2007.

Last reviewed November 2008 by ]]>Kari Kassir, MD]]>

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.