Fabry Disease
· What
is Fabry Disease?
· Symptoms
of Fabry Disease
· Incidence
· Screening
and Testing
· Other
Resources
What is Fabry Disease?
Fabry disease is an inherited disease that affects anywhere from a few thousand
to 50,000 people worldwide. The most common form of Fabry appears at twenty
years of age. This disease is caused by a deficiency of lysosomal enzyme a-galactosidase,
which causes abnormal deposits of a fatty substance called globotriaosylcera-mide
in the blood vessels throughout the body.
As abnormal storage of the fatty compound increases with time, the channels
of these vessels become narrowed. The narrowing leads to a decreased blood flow
and decreased nourishment of the tissues normally supplied by those vessels.
The problem occurs in all blood vessels throughout the body, but affect in particular
the skin, the kidneys, the heart, the brain, and the nervous system. A characteristic
rash around the waist develops, and there is an increased risk of kidney and
heart disease as well as a reduced life expectancy.
Symptoms
In children it begins with episodes of pain and burning sensations in hands
and feet.
Young patients often develop spotted dark red skin rash seen more from umbilicus
to knees, decreased ability to perspire, change in cornea that does not affect
vision.
Fabry is a progressive disease. Symptoms of kidney, heart, and/or neuro involvement
occur between ages of 30-45.
Incidence
The defective gene is on the X-chromosome. The X-chromosome is one of two chromosomes
that determine a person's sex. Females have two X-chromosomes, one from each
parent. Males have X-chromosome from mom and Y-chromosome from dad.
If mother is a carrier of the Fabry Disease, all her male and female children
have 50% chance of inheriting a defective gene from their mother.
If father is carrier all daughters will inherit the defective gene, since it
is the one X-chromosomes that is transferred from fathers to daughters. Son,
who get the Y-chromosome from their father do not inherit the defective gene.
A female Fabry carrier has one X-chromosome with a defective gene and normal
one X-chromosome, thus she is usually protected. Males, on the other hand, have
only one X-chromosome, so when that gene is defective, they express the disease.
Fabry Disease occurs in all ethnic groups. It is estimated that one in 200 people
is a carrier, and one in 40,0000 has the disease.
Screening
Once pregnant an Amniocentesis and a Chorionic Villus Sampling can diagnose
Fabry in the fetus before birth. Amniocentesis is done between the 15th and
16th week of pregnancy. A needle is inserted into the mother's abdomen and a
sample of the fluid that surrounds the baby is taken. In CVS a sample of cells
from the placenta is retrieved by the doctor during the 10th and 12th week of
a pregnancy.
When Fabry disease is suspected either on basis of clinical signs or by discovery
of relative with Fabry disease it is confirmed by simple blood test
that measures activity of enzyme.
For more Information contact:
International Center for Fabry Disease
Dept. of Human Genetics, Mount Sinai School of Medicine
5th Avenue and 100th Street
New York, NY 10029
Telephone: 212-659-6700
For
Genetic Counseling and Screening Resources – Click Here