2. GALACTOSEMIA
• Galactosemia is a rare genetic metabolic genetic
disorder that affects an individual's ability to metabolize
the sugar galactose properly.
• Galactosemia means "galactose in the blood ".
• Galactose is a type of food sugar found mainly in dairy
products, and is produced within the body as well.
3. lactose glucose galactose
• Lactose in food (such as dairy products) is broken down
by the enzyme lactase into glucose and galactose.
• Glucose can be used as a source of energy by the body,
but galactose needs to be further broken down by a
specific chemical (enzyme) before it can be utilized.
4. • An autosomal recessive mode of inheritance that
confers a deficiency in an enzyme responsible for
galactose degradation.
• Meaning a child must inherit one defective gene from
each parent to show the disease.
5. CAUSES OF GALACTOSEMIA!!!!
• Individuals with this disease the enzyme for the
metabolism of galactose is diminished or missing entirely
6. • This leads to toxic level of galactose-1-phosphate in
various tissue resulting in hematomegaly (an enlarged
liver), chirrosis, renal failure, cataracts, brain damage
and ovarian failure (female only).
7. Types of galactosemia!!!
• Galactose is converted into glucose into 3 types of
enzyme.
• Known as the Leloir pathway.
TYPE GENE LOCUS ENZYME NAME
1 GALT 9p13 galactose-1- classic
phosphate uridyl galactosemia
transferase
2 GALK1 17q24 galactokinase galactokinase
deficiency
3 GALE 1p35-36 UDP galactose galactose
epimerase epimerase
deficiency
8.
9. • Classic galactosemia, also known as type I, is the most
common and most severe form of the condition.
• If infants with classic galactosemia are not treated
promptly with a low-galactose diet, life-threatening
complications appear within a few days after birth.
• Typically develop feeding difficulties, a lack of energy
(lethargy), a failure to gain weight and grow as
expected (failure to thrive), yellowing of the skin and
whites of the eyes (jaundice), liver damage, and
bleeding.
10. • Galactosemia type II (galactokinase deficiency) causes
fewer medical problems than the classic type.
• Marked by an accumulation
of galactose and galactitol secondary to the decreased
conversion of galactose to galactose-1-
phosphate by galactokinase.
• Affected infants develop cataracts, but otherwise
experience few long-term complications.
11. • The signs and symptoms of galactosemia type III vary
from mild to severe and can include cataracts, delayed
growth and development, intellectual disability, liver
disease, and kidney problems.
• There are 2 forms of epimerase deficiency: benign
RBC deficiency and Severe liver deficiency.
• Severe form is similar to galactosemia.
12. Treatment for galactosemia!!!!
• It is stated that the only treatment for galactosemia is by
eliminating lactose and galactose from diet……
14. • Is also called lactose deficiency or hypoclastia.
• Inability of a person to digest lactose in the diet.
• Not a disorder but a genetically determined
characteristic.
• It is inherited in the pattern of autosomal recessive
diseases
15. • Lactose intolerant individuals have insufficient levels
of lactase, an enzyme that catalyzes hydrolysis of
lactose into glucose and galactose, in their digestive
system.
• When lactose moves through the large
intestine (colon) without being properly digested, it can
cause uncomfortable symptoms such as gas, belly
pain, and bloating.
16. • Almost all Asians and Native Americans are lactose
intolerant, and up to 80% of African Americans and
Hispanic Americans also have symptoms of lactose
intolerance.
• Their ancestors did not eat dairy foods, so their bodies
were not prepared to digest dairy, and they passed
these genes on from generation to generation.
18. Types of lactose intolerance!!!
• three types:
1.Primary lactase deficiency is genetic, only affects
adults and is caused by the absence of a lactase
persistence allele. It is the most common cause of
lactose intolerance as a majority of the world's
population lacks these alleles.
19. 2.Secondary, acquired, or transient lactase
deficiency is caused by an injury to the small intestine,
usually during infancy, from
acute gastroenteritis, diarrhea,chemotherapy,intestinal
parasites or other environmental causes.
20. 3.Congenital lactase deficiency is a very
rare, autosomal recessive genetic disorder that prevents
lactase expression from birth.
It is particularly common in Finland.
People with congenital lactase deficiency are unable to
digest lactose from birth, and they are unable to digest
breast milk.
21. What causes lactose intolerance ?
• Is due to the mutation in LCT genes.
• Mutation in both the LCT genes will result in this
diseases as it is autosomal recessive.
• Certain mutation in the LCT gene allow lactase continue
to be expressed after stopping breast feeding.
• The LCT gene which encodes the lactase protein is
located on the long arm (q) of chromosome 2 in region
21. (2q21)
22. Treatment of lactose intolerance!!!
• avoidance of dietary lactose
• substitution to maintain nutrient intake
• regulation of calcium intake
• use of enzyme substitute also known as enzyme
replacement theraphy in which mostly intravenous
injection containing the enzyme is given to the patients
23. POINT TO REMEMBER
• Lactose intolerance is the inability or insufficient ability to digest
lactose, a sugar found in milk and milk products.
• Lactose intolerance is caused by a deficiency of the enzyme lactase,
which is produced by the cells lining the small intestine.
• Not all people with lactase deficiency have digestive symptoms, but
those who do may have lactose intolerance.
• Most people with lactose intolerance can tolerate some amount of
lactose in their diet.
• People with lactose intolerance may feel uncomfortable after
consuming milk and milk products. Symptoms can include abdominal
pain, abdominal bloating, gas, diarrhea, and nausea.
24. • The symptoms of lactose intolerance can be managed with dietary
changes.
• Getting enough calcium and vitamin D is a concern for people with
lactose intolerance when the intake of milk and milk products is
limited. Many foods can provide the calcium and other nutrients the
body needs.
• Talking with a doctor or registered dietitian may be helpful in
planning a balanced diet that provides an adequate amount of
nutrients—including calcium and vitamin D—and minimizes
discomfort. A health professional can determine whether calcium and
other dietary supplements are needed.
• Milk and milk products are often added to processed foods.
Checking the ingredients on food labels is helpful in finding possible
sources of lactose in food products.