What Is DiGeorge Syndrome?
Definition of DiGeorge Syndrome
This disease shares my name DiGeorge, although there is no relation to us.
DiGeorge Syndrome, also known as 22q11.2 deletion syndrome, autosomal dominant immunodeficiency or velocardiofacial syndrome, is when part of chromosome number 22 is missing, resulting in heart defects, cleft palate, learning and development problems, mental health problems, thymus gland disfunction, and autoimmune diseases.
In utero view
22q11.2 Deletion Syndrome Named For Dr. Angelo DiGeorge
All humans have two copies of chromosome 22, one from each parent. Chromosome 22 contains about 500 to 800 genes and is responsible for the development of many body systems. During development in the womb, the missing parts (estimated between 30 and 40 genes) of this chromosome (commonly called deletion) cause defects in fetal development.
DiGeorge Syndrome is named after pediatrician Dr. Angelo DiGeorge, (April 15, 1921 to October 11, 2009)
He was a physician in my hometown of Philadelphia, PA but no immediate relation to our family. I had the great honor of meeting him once in the 1970s when I completed a rotation at St. Christopher's Hospital for Children, part of the Temple University network of hospitals.
He received his medical degree from Temple University in 1946. After three years in the Army (1947-1949) as a Captain and Chief of Medicine for 124th Station Hospital in Austria, he returned to Philadelphia to complete his pediatric residency at St. Christopher's Hospital for Children. He completed a post-doctoral fellowship in endocrinology at Jefferson Hospital of Philadelphia in 1954.
In 1965, Dr. Angelo DiGeorge, then Chief of Endocrinology and Director of the Pediatric Clinical at St. Christopher's Hospital for Children, literally made a name for himself in the annals of medicine. His ground breaking research resulted in bringing attention to a disorder whose primary symptom was absence of the thymus and other abnormalities, and named for him.
DiGeorge Syndrome is a common genetic disorder and affects one out of every 4,000 live births.
Until 1965, there had been no indepth research into this disorder which causes over 200 birth defects. It wasn't until after his research and resulting paper was presented that chromosome 22q11.2 deletion syndrome was officially named DiGeorge Syndrome.
Cleft Lip or Cleft Palate
Symptoms of DiGeorge Syndrome
DiGeorge Syndrome varies from patient to patient, can be noticeable at birth and in others doesn't present until the child is entering toddler years. All patients will not have every one of these symptoms, but will likely have a good number of them.
- Failure to thrive - often manifested when a child doesn't achieve benchmarks of growth due to failure to gain weight, disinterested in surroundings and food.
- Congenital heart defects (i.e. hole in the heart, septal defect)
- Blue skin tone (called cyanosis) due to poor circulation
- Very poor muscle tone
- Shortness of breath
- Neuromuscular problems
- Spasms of the mouth and throat
- Twitching in the hands, arms, and/or legs
- Recurrence of infections due to problems with T-cell response
- Poor kidney function
- Child is usually smaller in height compared to other family members
- Delay of milestones in infancy (sitting up, turning over)
- Difficulty in eating and/or swallowing
- Learning disabilities
- Low-set ears, wide set eyes or cleft palate (gap in roof of the mouth)
- Hooded eyes, long face or a flat groove in upper lip
- Attention Deficit Hyperactivity Disorder or Autism related disorders
- Impaired hearing, vision, speech
Good resource video with lots of detail
If the child has a heart defect which is commonly associated with DiGeorge Syndrome, the physician will order certain laboratory tests.
- A test called Fluorescence In Situ Hybridization (referred to as FISH) was developed that tested for deletions of chromosome 22q11 which were too tiny to be seen using a microscope.
- The FISH test is performed by a cytogenetic (clinical) laboratory only when a 22q11 deletion is suspected. It is not a routine test performed during amniocentesis or in obstetric bloodwork. However if the test comes back negative or normal, even though a physician has diagnosed DiGeorge Syndrome based on other clinical observations (heart defects, cleft palate, failure to meet childhood benchmarks,etc.), other types of FISH tests can be performed. More than 90 percent of patients with DiGeorge Syndrome will have a positive FISH test result.
Certain genetic tests will be performed which will include:
- Chromosomal microarray analysis (CMA),
- Fluorescent in situ hybridization (FISH) as mentioned above,
- TBX1 gene studies, and
- Multiplex ligation-dependent probe amplification (MLPA)
Laboratory tests will include:
- serum calcium and PTH (parathyroid) studies and
- a CBC (complete blood count).
T-cell function will be evaluated using:
- flow cytometry testing,
- reverse-transcriptase polymerase chain reaction assays (RT-PCR) and
- antibody response studies.
Imaging tests to diagnose thymus and heart abnormalities will include:
- MRI (magnetic resonance imaging),
- CT (computer tomography scan),
- ECG (echocardiogram), and
- AMRA and MRA (angiography and magnetic resonance angiography)
These tests will be repeated over time to mark the progression or improvement of the disease while the patient is undergoing therapies, surgery and/or medication adjustments.
2 Minute video
Treatment - researched by awordlover
Treatments and therapy will address each problem as it appears:
- Patients are given Calcium and Vitamin D supplements and usually put on a low phosphorus diet. If the patient's parathyroid gland tissue is healthy and unharmed, it is possible for the child's parathyroid gland to regulate their own body's calcium and phosphorus levels without having to be on a special diet.
- Thymus gland - if the child has frequent infections - colds, throat or ear infections, etc - children with limited thymus function generally improve as they get older. Following antibiotic protocols for infection and vaccines are strongly urged.
- Children with severe thymus gland dysfunction or no thymus gland are very susceptible to infections. Treatment protocol involved transplanting thymus tissue or special cells from bone marrow.
- Cleft palates are surgically repaired.
- Heart defects are repaired and blood circulation problems are monitored.
- Psychotropic medications are offered for children who develop ADHD, depression, schizophrenia or other behavior disorders.
- Speech therapy for verbal skills, occupational therapy to re-learn life skills, and therapy for social skills are recommended for overall development.
Thymus transplant is still in experimental stages at Duke University Medical Center.
Physicians are trying the procedure in the small percentage of DiGeorge Syndrome children who lack a thymus gland because either it was not present or it was removed during heart surgery as a newborn or small child. Tissue is obtained from donor families, ascertained to be disease free and implanted into the leg muscles.
In an August 2003 study, five of the six children who received the thymus gland transplant along with immunosuppressive drugs have gone on to develop a fully working immune system. One died due to illness before the surgery.
Although there is no cure for DiGeorge Syndrome, researchers feel that thymus transplants and subsequent research offers much hope to DiGeorge Syndrome children.
The Faces of DiGeorge Syndrome
Children diagnosed with DiGeorge Syndrome who grow up to have children of their own have a 50/50 chance of their children having the chromosome 22 deletion gene with each pregnancy. However, studies are showing that most children with DiGeorge Syndrome are usually the first person in their family to have it.
Since we have so many medical resources available geneticists are taking case histories of the parents to see if they have a mild form of the syndrome.
Once a parent is found to have 22q11 deletion, other family members will need to be tested, including siblings, children and parents of the affected parent.
This syndrome doesn't skip generations.
If a parent has VCFS (velocardio facial syndrome) but no heart problems, they can have a child with VCFS and heart defect. This disease varies with the amount of loss of the gene.
Some people have significant loss of the chromosome and others have a mild loss of 22q11. Other aspects of the disorder also vary among family members with 22q11 deletions.
Health Care Team
Once diagnosed with DiGeorge Syndrome, your child will have a comprehensive health care team to cover each affected body system. This may include any or all of the following:
- Heart Specialist
- Immune System Specialist
- Infectious Disease Specialist
- Oral and Maxillofacial surgeon (cleft lip/palate)
- Occupational Therapist
- Speech Therapist
- Mental Health Professionals
Chicago Cubs Pitcher Ryan Dempster's daughter has DiGeorge Syndrome.
Resources - researched and suggested by awordlover
22q and You Center
The Department of Clinical Genetics
The Children's Hospital of Philadelphia
One Children's Center
34th Street and Civic Center Boulevard
Philadelphia, PA 19104 Call: (215)590-2920 or Fax: (215)590-3298
Chromosome 22 Central
338 Spruce Street North
Ontario, Intl P4N 6N5
Canada Call: (705)-268-3099
Genetic and Rare Diseases (GARD) Information Center
PO Box 8126
Gaithersburg, MD 20898-8126
Call: (301)251-4925 or Fax: (301)251-4911
Toll Free: (888)205-2311
For Hearing Impaired, use TDD: (888)205-3223
International 22q11.2 Deletion Syndrome Foundation, Inc.
P.O. Box 424
Matawan, NJ 07747
Toll Free: (877)739-1849 or use Email: email@example.com
Cleft Lip and Palate Foundation of Smiles
2044 Michael Ave SW
Wyoming, MI 49509
FACES: The National Craniofacial Association
PO Box 11082
Chattanooga, TN 37401
Call: (423)266-1632 or Fax: (423)267-3124
Toll Free: (800)332-2373 or Email: firstname.lastname@example.org
Velo-Cardio-Facial Syndrome Educational Foundation
P.O. Box 874
Milltown, NJ 08850
USA Call: (214)360-4740 or Email: email@example.com
© 2013 awordlover