Galactosemia

DR.SUNIL BHOYE
BAMS, MPH(NUTRITION)

1. Galactosemia DR.SUNIL BHOYE MPH(NUTRITION) 1

2. Content Introduction Synonyms and Subdivisions Structure of Lactose breaking in to Glucose and Galactose due to enzyme Gale How does Galactosemia occur? Can it be passed to future generation or is it heredity? Brief History of Galactosemia Type of mutation 2

3. Content Where does it occur in a karyotype /chromosome/gene. Signs/Symptoms in Adults & Infants  How is it diagnosed  Is it curable/How is it treated References 3

4. Introduction Galactosemia is a rare, hereditary disorder of carbohydrate metabolism that affects the body’s ability to convert galactose (a sugar contained in milk, including human mother’s milk) to glucose (a different type of sugar). The disorder is caused by a deficiency of an enzyme galactose-1-phosphate uridylyl transferase (GALT) which is vital to this process. Early diagnosis and treatment with a lactose-restricted (dairy-free) diet is absolutely essential to avoid profound intellectual disability, liver failure and death in the newborn period. 4

5. Introduction Galactosemia is inherited as an autosomal recessive genetic condition. Classic galactosemia and clinical variant galactosemia can both result in life-threatening health problems unless treatment is started shortly after birth. A biochemical variant form of galactosemia termed Duarte is not thought to cause clinical disease due to lactose consumption 5

6. Synonyms and Subdivisions Synonyms of Galactosemia Galactose-1-phosphate uridylyl transferase deficiency Transferase deficiency galactosemia GALT deficiency Subdivisions of Galactosemia Classic galactosemia Clinical variant galactosemia Biochemical variant galactosemia (Duarte variant galactosemia ) 6

7. Structure of Lactose breaking in to Glucose and Galactose due to enzyme Gale 7

8. How does Galactosemia occur? Galactosemia occurs when a child inherits a defective gene from each parent. Lacking a normal copy of this gene, the child cannot make one of the enzymes necessary to breakdown galactose . There is a simple sugar called galactose where the body produces. Also there is a large sugar called lactose. 8

9. Can it be passed to future generation or is it heredity? The genetically significant mutations occur in reproductive cells and can therefore be transmitted to future generations. Natural selection acts upon the genetic diversity generated by mutation to preserve beneficial mutations and eliminate deleterious ones. It is a heredity recessive disease. 9

10. Brief History of Galactosemia Galactosemia was first discovered in 1908 by the physician Von Ruess . It was first recognized and described in detail in 1935 by Mason and Turner. Leloir worked out the metabolic pathway and the process of sugar-nucleotides and won the Nobel prize in Chemistry in 1970 for his work. The defective gene that caused it was found in 1956.It was first found to be detectable through a newborn screening method in This method was developed by Guthrie and Paigen . Galactosemia affects 1 in every 55,000 newborns. 10

11. Type of mutation The gene mutation (usually "Q188R") that causes galactosemia is inherited in what is called an autosomal recessive pattern. Galactosemia is a recessive gene. 11

12. Where does it occur in a karyotype /chromosome/gene. Most people with galactosemia are missing an enzyme (called GALT) in chromosome to get the disorder, a child must inherit one defective gene from each parent. Galactosemia is inherited in an autosomal recessive manner, meaning a child must inherit one defective gene from each parent to show the disease. Heterozygotes are carriers, because they inherit one normal gene and one defective gene. Carriers show no symptoms of galactosemia 12

13. Signs/Symptoms in Adults & Infants Adults Speech difficulties Learning disabilities Ovarian failure for female Infants Lethargy Vomiting Diarrhea Failure to thrive Jaundice Hypoglycemia, Hypotonia 13

14.  How is it diagnosed In most states, babies are tested for galactosemia at birth. Using a tiny blood sample taken from the baby's heel, the test checks for low levels of the GALT enzyme. This allows for prompt treatment, which can substantially prevent the serious symptoms of this disorder 14

15. Galactosemia 15

16.   Is it curable/How is it treated The only way to treat galactosemia is through dietary restrictions. People with the disorder must stay away from foods and drinks containing galactose , including milk, cheese, and legumes (dried beans). People who have GALT should stay away from food which have GALT. It is not cure but there are several treatments 16

17. Dietary Management Initial management that continues throughout life Eliminate galactose from the diet Lactose* Galactose * Life-long diet Calcium supplements Avoid some pharmaceuticals Endogenous galactose Vitamin K 17

18. 18 Low Galactose Food Pattern Food Group Allowed Not Allowed Milk & Milk Substitutes Soy or MCT Formula: Isomil , Nutramigen , Prosobee , Pregsestimil Breast Milk, Animal Milk, Cheeses, Butter, Ice Cream, Yogurt Fruits Most Frozen, Fresh, Canned & Dried* Dates, Papaya, Persimmon, Watermelon Vegetables Most Frozen, Fresh, Canned, & Dried* Bell Peppers, Tomatoes Meats & Meat Substitutes Beef, Poultry, Lamb, Ham Pork, Fish, Game, Kosher Franks, Eggs, Nuts None* Breads Rice, Pasta, Cereals, Breads None* Fats Oil, Lard, Shortening, Mayonnaise Butter, some margarines

19. Long Term Management Outpatient review throughout life Dietary compliance Growth Biochemical Analysis Red Cell Galactose-1-Phosphate Urinary Galactitol Development Speech Cognition Motor skills Ophthalmology 19

20. References Galactosemia(GALT) By Raveeja V Deshpande. NORD (National Organization For Rare Disorders) https://www.indianpediatrics.net/jan2016/21.pdf JH Walter, JE Collins & JV Leonard, 1999. LK Mahan & S Escott -Stump, 1996. 20