Glycogen Storage Disease - Jewish Genetic Disease

Description
Glycogen storage disease is an autosomal recessive genetic disease that involves disorders of metabolism. The disease is caused by defects in a gene that code for certain enzymes. Enzymes are responsible for conversion of one substance into another. The enzymes that are absent are those that covert glycogen to glucose, thereby causing an accumulation of glycogen in certain tissues and a lack of glucose needed for energy and muscle activity. The defect is usually present in childhood, though there are some types of this disease that have adult onset.

The following are eight types of Glycogen Storage Disease. Type III or Forbes-Cori Disease affects the Sephardic Jewish Community while Type Ia or von Gierke disease affects the Ashkenazi Jewish Community.

Glycogen synthase deficiency
   • Ia - Glucose-6-phosphatase deficiency (von Gierke disease)
   • II - Acid maltase deficiency (Pompe disease)
   • III - Debranching enzyme deficiency (Forbes-Cori disease)
   • IV - Transglucosidase deficiency (Andersen disease, amylopectinosis)
   • V - Myophosphorylase deficiency (McArdle disease)
   • VI - Phosphorylase deficiency (Hers disease)
   • VII - Phosphofructokinase deficiency (Tarui disease)

Symptoms
GSD TYPE IA
The most frequent first symptoms noted in infants with GSD Ia include an enlarged liver and low blood sugar (hypoglycemia) due to difficulty controlling the blood sugar. This often results in chronic hunger, fatigue, and irritability. Other symptoms that may develop include: a variety of biochemical abnormalities and delayed growth and development seizures, an enlarged liver, renal problems, slow growth and short stature, can be fatal.

GSD TYPE III
This disorder may cause systemic symptoms but in some cases it is limited to specific tissues. Symptoms include muscle cramping and weakness, although some types of GSD cause more severe symptoms of hypoglycemic seizure and enlarged heart. Other types manifest enlarged spleen and liver as well progression to liver cirrhosis in adults and growth retardation in children.

Incidence and Carriers
Disease frequency: GSD I occurs 1 in 20,000 Ashkenazi Jews and in 1 in 100,000 in general population. The Carrier frequency for GSD Ia among the Ashkenazi Jewish population is approximately 1/130 with the carrier frequency for US general population currently unknown.

Disease frequency: GSD III occurs in 1 in 5400 North-African Jews and in 1 in 200,000 in the general population. Carrier frequency: Estimated to be 1 in 35 in North African Jews.

The disease is transmitted through heredity. Both parents have to carry the mutated gene for there to be a possibility of transmission to their child.
If both are carriers:
   • There is a One in Four chance that the child will inherit the mutated gene from each parent and have the disease
   • There is a One in Four chance that the child will inherit normal genes from both parents and be completely free of the disease.
   • There is a Two in Four chance the child will inherit one of a mutated gene from one parent and a normal gene from the other parent, and in this case, be a carrier like the parents, but free of the disease.

Treatment
Treatment for GSD involves providing the body with an outside supply of glucose Although no specific treatment is available for GSD dietary restrictions has proven to be effective in the management of the disorder. Careful and strict adherence to a dietary regimen may reduce liver size, prevent hypoglycemia, reduce muscular symptoms, and allow for growth and development.

Testing
Diagnosis of GSD I: Blood test, liver and kidney ultrasound for measurement, genetic test and liver biopsy.

Genetic testing to detect gene mutation.

Resources and More
GSD TYPE 1 –TESTING:
Mount Sinai School of Medicine Diagnostic Testing Laboratory
Tel: 212-241-6947

Genzyme Genetics Molecular Diagnostic Laboratory
Tel: (800) 255-7357

LabCorp Molecular Biology
Tel: (800) 345-4363

Quest Diagnostics, Inc. Molecular Genetics Laboratory
Tel: (800) 642-4657

The Jewish Genetic Diseases Center of Greater Phoenix is located at:
12701 N. Scottsdale Road, Suite 201
Scottsdale, AZ 85254
Phone: (480) 668-3347

University of Miami Miller School of Medicine
Miami, Florida
Telephone: 305-243-4524
Cellular: 786-897-9587

The Victor Center for Jewish Genetic Diseases
Albert Einstein Medical Center
5501 Old York Road, Levy 2 West
Philadelphia, PA 19141
(215) 456-8722

GSD TYPE 3 –TESTING:

Mount Sinai Hospital Medical Center
California at 15th Street
Chicago, IL 60608
Phone: (773) 542-2000
Fax: (773) 257-6208
Email: shs@sinai.org
Website: www.sinai.org
Provides carrier screening through the Refoenu Jewish Health Care Society.

Mount Sinai Touhy Health Center*
2901 West Touhy Avenue
Chicago, IL 60645
Phone: (773) 973-7353
Provides carrier screening through the Refoenu Jewish Health Care Society.

Refoenu Jewish Health Care Society
Phone: (773) 761-1892
Contact: Dr. Yaakov Friedman
Provides education awareness and screening.

Genzyme Analytical Services
5300 McConnell Ave
Los Angeles, CA 90066
Tel: (800) 353-1550
http://www.jewishgeneticscenter.org/genetic/nsgc
Genetic Screening Programs – State by state Listing (Each states screens newborns for different genetic diseases)

Support
Association for Glycogen Storage Disease AGSD
Hollie Swain
Box 896
Durant, IA 52747
Tel./Fax: (319) 785-6038

GSDnet
An electronic mailing list intended to allow communication between families, individuals, and professionals with an interest in glycogen storage disease.
To subscribe to GSDnet, send this message:
subscribe to this address: listserv@maelstrom.stjohns.edu
Leave the subject line blank.

Association for Glycogen Storage Disease (UK)
http://www.agsdus.org/html/emailotherswithgsd.htm
9 Lindop Road
Hale, Altricham
Cheshire, WA159DZ
United Kingdom
Tel: 1619807303
Fax: 1612263813
Email: president@agsd.org.uk
Internet: http://www.agsd.org.uk