Galactose metabolism involves the conversion of galactose derived from milk into glucose in the liver, which is crucial for infants. Galactosemia, an inherited metabolic disorder, causes high levels of galactose in the blood due to deficiencies in enzymes like galactokinase and galactose 1-phosphate uridyl transferase, leading to serious health issues. Management of galactosemia requires strict dietary avoidance of galactose-containing foods, particularly milk and dairy products.

1. GALACTOSE METABOLISM
• DR ROHINI C SANE
• PROFESSOR
• DEPARTMENT OF BIOCHEMISTRY
• DR D Y PATIL MEDICAL COLLEGE
• EBENE

2. GALCTOSEMIA
• INBORN ERROR OF METABOLISM
• BABIES WITH DEFECT CANNOT UTILISE GALACTOSE
• GALACTOSE FROM MILK –PART OF MILK –ONLY FOOD OF BABIES
• NORMAL CONDITION –GALACTOSE CONCENTRATION IN SYSTEMIC
BLOOD –NIL
• GALACTOSEMIA –HIGH LEVEL OF GALACTOSE IN BLOOD

3. SOURCES OF GALACTOSE
• INTESTINAL HYDROLYSIS OF DIETARY LACTOSE PRESENT IN MILK
• IMPORTANCE OF GALACTOSE –ESSENTIAL FOR FORMATION OF CERTAIN
GLYCOPROTEINS,CERBROSIDES ,MILK DURING LACTATION
LACTOSE +LACTASE GLUCOOSE +GALACTOSE
ABSORPTION OF LACTOSE - ACTIVE TRANSPORT IN INTESTINAL LUMINAL
CELLS
LACTOSE -CARRIED BY PORTAL BLOOD TO LIVER
PORTAL BLOOD THAT ENTERS LIVER CONTAINS GLUCOSE +GALACTOSE
+FRUCTOSE
SYSTEMIC BLOOD THAT LEAVES LIVER CONTAINS GLUCOSE + FRUCTOSE

4. METABOLISM OF GALACTOSE(LIVER)
GALCTOSE GLYCOGEN
ATP
ADP GALACTOKINASE (1)
GALCTOSE 1 PHOSPHATE UDP GLUCOSE
GALACTOSE 1 PHOSPHATE UDP GALACTOSE
EPIMERASE (3)
URIDYL TRANSFERASE (2)
GLUCOSE 1 PHOSPHATE UDP GALACTOSE
MUTASE
LACTOSE
SYNTHETASE
GLUCOSE 6 PHOSPHATE
GLYCOLYSIS LACTOSE

5. GALACTSEMIA
THREE AUSOMAL RECESSIVE INBORN ERRORS OF GALACTOSE METABOLISM
1. GALACTOKINASE DEFICIENCY
2. GALACTOSE 1 PHOSPHATE URIDYL TRANSFERSE (GALT)
3. GALACTOSE 4 EPIMERASE DEFICIENCY

7. I GALACTOKINASE DEFICIENCY
• GALACTOSE +ATP+ GALACTOKINASEGALACOSE 1 PHOSPHATE
• CHARACTRISTICS
• ACCUMULATION OF GALACTOSE IN BLOOD & TISSUES
• CATARACT FORMATION DUE TO REDUCTION OF GLUCOSE BY ALDOSE
REDUCTASE TO GALACTIOL( DULCITOL)---LENSE BECOMES IMPERABLE
•

10. GALACTOSE 1 PHOSPHATE URIDYL TRANSFERSE (GALT)
• INCIDENCE : 1 IN 50000 BIRTHS
• ENZYME DEFICIENCY : GALACTOSE 1 PHOSPHATE URIDYL TRANSFERSE (GALT)
• ACCUMULATION OF GALACTOSE & GALACTOSE -1-PHOSPHATE
• CLINICAL AND BIOCHEMICAL FEATURES
VOMITING & DIARRHOEA WITH FAILURE TO THRIVE
HYPOGLYCEMIA
JAUNDICE ,HEPATOMEGALY,CIRRHOSIS
IRREVERSIBLE MENTAL RETARDATION
RENAL TUBULAR DAMAGE &GENERALISED AMINOACIDURIA (FANCONI SYNDROME )DUE
TO GALACTOSE- 1 -PHOSPHATE IN KIDNEY
BACTERIAL SEPSIS WITH E .COLI LEADING TO DEATH

11. III GALACOSE- 4- EPIMERASE DEFICIENCY
• VERY RARE AND ASYMPTOMATIC
• ENZYME MAY BE FOUND DEFICIENT IN ERYTHROCYTES BUT FOUND IN LIVER

13. MANAGEMENT OF GALACTOSEMIA
• ALL THREE TYPES OF GALACTOSEMIA CAN BE TREATED BY
ELIMINATION OF GALACTOSE IN DIET (MILK & MILK PRODUCTS )

21. THANK YOU