Galactosemia is a rare genetic disorder that affects the body's ability to properly metabolize the sugar galactose. It is caused by a deficiency in one of the three enzymes (GALT, GALK1, GALE) required to break down galactose through the Leloir pathway. Left untreated, galactosemia can cause intellectual disability, liver and kidney damage, cataracts, and other issues. It is typically detected through newborn screening and treatment involves eliminating galactose and lactose from the diet through life.

1. Galactosemia
By
Farshid Mokhberi
Shahid Beheshti University of Medical Science

2. Galactosemia

3. 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.

4. Galactosemia and organs:

6. 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:

7. Gene location:
GALE
GALT
GALK1

8. Normal metabolic pathway for galactose
in humans:

9. Sign and symptoms:
 Intellectual disability
 Hepatomegaly
 Hepatic failure
 Renal failure
 Cataract
 Premature ovarian failure
 Dysmetria
 Ataxia

11. 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.

12. 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.

13. Treatment:
 The only treatment for classic
galactosemia is eliminating lactose
and galactose from the diet.
 Gene therapy

14. 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.

15. Thanks for
your
attention

16. 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