Glycogen storage disease

1. Glycogen storage diseases are grouped of inherited disorders characterized by deposition of an abnormal type or quantity of glycogen in the tissues. • They are mainly due to deficiency of one of enzyme of glycogenolysis or glycogenesis. Glycogen storage disease

2. Von Gierke’s disease • It is due to deficiency of glucose -6-phosphatase in liver and kidnney. • It is commonest type • Accumulation of large amount of glycogen glycogen in liver – disturbance in liver function. • Enlargement of liver and kidney. • Fasting hypoglycemia associated with ketosis and hyperlipaemia. Type I

3. Pompe’s disease • Deficiency of acid maltase. • Glycogen accumulation in lysosome. Type II

4. limit dextrinosis disease(cori disease). • Due to deficiency of debranching enzyme of in liver ,muscles and heart. • Glycogen has many short branches. Type III

5. Amylopectinosis(anderson’s disease) • Due to absence of branching enzyme .glycogen formed have no or few branches. Type IV

6. Mc –Ardle’s disease. • Due to muscle phosphorylase . Glycogen is accumulated in muscle and breaking does not occur during exercise. • Muscle cramps are present. Type V

7. Her’s disease • Due to deficiency of liver phosphorylase. Type VI

8. Due to deficiency of phosphofructokinase enzyme in the muscle. Type VII

9. Hereditary deficiency • Aldolase –B enzyme  accumulation of fructose 1- P • Frcutose 1,6 –biphosphatase  accumulation of fructose 1,6 biphopate (hereditary fructose intolerance). • Accumulation of F -1-P and F -1 ,6BPinhibiton of glycogen phosphorylase  inhibition of glycogenolysis liver glycogen + hypoglycemia. Fructosaemia

10. Appearance of fructose in urine . It is a result of fructosaemia. • Conversion of glucose to fructose: • Free fructose found in semen and amniotic fluid • Deficiency of fructose in seminal fluid correlates with male infertility. • Derived from conversion of glucose to fructose. • Formed in the seminal fluid vesicle as follows: Fructosuria

11. Glucose ALDOSE REDUCTASE sorbitolsorbitoldehydrogenasefructose NADPH + H+ NADP+ NADH+ NADH + H+ As follows

12. Increase of galactose concentration in blood. • Causes: It is due to deficiency of one of the following enzyme : Galacotokinase , galactose 1 uridyltransferase and UDP-galactoseepimerase. • Pathological effects: • Cataract : ( opacity of the eyes lens) • Galactosereduced by aldosereductasegalactitol cataract • l galactosaemia

13. Liver failure • Mental retardation • Galactosuria: increase excretion of galactose in urine. Cont.

14. Rise in blood glucose level above normal average concentration.equal or more than 140mg/dl. • Occurs in • Diabetes mellitus • Patient receiving intravenous fluid containing glucose. • Temporarily in severe stress. • After cerebrovascular accidents. Hyperglycemia

15. Decrease in blood glucose level below normal average concentration : less than 40mg/dl. • Symptoms: • Release of acute adrenaline which leads to 1. Sweating ,weakness, anxiety, nervousness and hunger. hypoglycemia

16. Due to acidosis(ketosis) Ketosis coma

17. Insulin –dependent (or type I) diabetes mellitus (DDM) • Absolute deficiency of insulin caused by destruction of Beta cells of the pancreas . • stimulus form environment( viral infection) • Autoimmune condition called insulinitis • “Honey moon” transient condition. • ketosis DDM

18. Most common • Non-insulin dependent diabetes mellitus(NIDDM). • Develops without any symptoms. • Dysfunction of Beta cells • Resistance to insulin action at cellular level. • NIDDM is based on completely genetic background. • No virus or autoimmune antibodies • Over 80% of NIDDM are obese. Type II

19. Caused by excessive absorption of iron and its precipitation in tissues as: • 1. skin: causing discolouration. • 2. causing diabetes mellitus • Liver : causing hepatic cirrhosis. Bronze diabetes

20. Due to hyperlactatemia .This type may occur in some patients who receive oral hypoglycemia drug called : phenformin. Lactic acidosis