Download - Galactosemia by Farshid Mokhberi
Galactosemia
By
Farshid Mokhberi
Shahid Beheshti University of Medical Science
Galactosemia
Galactosemia :
is a rare genetic metabolic disorder that affects an
individual's ability to metabolize the sugar galactose
properly.
Galactosemia follows an autosomal recessive mode of
inheritance that confers a deficiency in an enzyme
responsible for adequate galactose degradation.
Galactosemia and organs:
TYPES:
Type OMIM Gene Locu
s
Enzyme Name
Type 1 230400 GALT 9P13 Galactose1-
phosphat uridyl
transferase
Classic
galactosemia
Type 2 230200 GALK1 17q24 galactokinase Galactokinase
deficiency
Type 3 230350 GALE 1p36-
p35
UDP galactose
epimerase
UDP-Galactose-
4-epimerase
deficiency
Galactose is converted into glucose by the action of three enzymes,
known as the Leloir pathway:
Gene location:GALE
GALT
GALK1
Normal metabolic pathway for galactose
in humans:
Sign and symptoms:
Intellectual disability
Hepatomegaly
Hepatic failure
Renal failure
Cataract
Premature ovarian failure
Dysmetria
Ataxia
Diagnosis:
Galactosemia is normally first detected through newborn screening, or NBS.
A galactosemia test is a blood test (from the heel of the infant) or urine test that checks for three enzymes that are needed to change galactose sugar that is found in milk and milk products-into glucose. A person with galactosemia doesn't have one of these enzymes. This causes high levels of galactose in the blood or urine.
Screening tests:
Beutle’s test:
Beutle's test: also known as the
fluorescent spot test, is a screening
test that used to identify enzyme
defects.
Treatment:
The only treatment for classic
galactosemia is eliminating lactose
and galactose from the diet.
Gene therapy
Galactosemia is sometimes
confused with lactose intolerance: Galactosemia is a more serious
condition. Lactose intolerant individuals have an acquired or inherited shortage of the enzyme lactase, and experience abdominal pains after ingesting dairy products, but no long-term effects. In contrast, a galactosemic individual who consumes galactose can cause permanent damage to their bodies.
Thanks for
your
attention
Refrenses:
http://ghr.nlm.nih.gov/gene/GALK1
http://ghr.nlm.nih.gov/gene/GALE
http://ghr.nlm.nih.gov/gene/GALT
www.ncbi.nlm.nih.gov/guide/genetics-
medicine
http://www.ncbi.nlm.nih.gov/gap