GALACTOSEMIA AND LACTOSE

INTELORANCE!!!

GALACTOSEMIA AND LACTOSE

INTELORANCE!!!

GALACTOSEMIAGALACTOSEMIA

• 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.

• 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.

lactose glucose galactose

• 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.

CAUSES OF GALACTOSEMIA!!!!CAUSES OF GALACTOSEMIA!!!!

• Individuals with this disease the enzyme for the metabolism of galactose is diminished or missing entirely

• 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).

Types of galactosemia!!!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-phosphate uridyl

transferase

classic galactosemia

2 GALK1 17q24 galactokinase galactokinase deficiency

3 GALE 1p35-36 UDP galactose epimerase

galactose epimerase deficiency

• 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.

• 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.

• 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.

Treatment for galactosemia!!!!Treatment for galactosemia!!!!

• It is stated that the only treatment for galactosemia is by eliminating lactose and galactose from diet……

LACTOSE INTOLERANCELACTOSE INTOLERANCE

• 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

• 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.

• 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.

Symptoms of lactose intolerance!!!!Symptoms of lactose intolerance!!!!

• abdominal • bloating • cramps • flatulence• diarrhea• nausea• borborygmi(rumbling stomach)• vomiting

-after consuming significant amounts of lactose

Types of lactose intolerance!!!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.

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.

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.

What causes lactose intolerance ?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)

Treatment of lactose intolerance!!!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

POINT TO REMEMBERPOINT 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.

• 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.