Biochemical Genetics

1. Biochemical Genetics
Medical Genetics
MPH
2-1-15

2. Learning Objectives
• By the end of this lecture……….we all should
be able to appreciate:
– Different groups of biochemical disorders.
– Features of Common biochemical disorders.

3. Metabolic disorders
• Mostly inherited in an autosomal recessive or X-
linked manner
• The disorder can also manifest in the
heterozygous state
– If the reaction is catalyzed by an enzyme is rate
limiting
• Tyrosine hydroxylase catalyses the reaction in which L-
tyrosine is hydroxylated to DOPA, the rate limiting step in
the biosynthesis of catecholamines, alterations in the
enzyme activity may be involved in disorders such as
Parkinson's disease and schizophrenia.
– The gene product is part of a multimcric complex.

4. Enzyme Deficiencies
Q1. D/D of Homocystinuria
Q2. Dx and Treatment if any?

5. Sites of Enzyme Deficiencies

6. Enzymes Involved in Phenylalanine
metabolism and deficiency states

7. Urea Cycle Disorders
Enzyme Deficiencies
• The urea cycle is a five-step metabolic pathway that takes place primarily in liver
cells for the removal of waste nitrogen from the amino groups of amino acids
arising from the normal turnover of protein.
• It converts two molecules of ammonia and one of bicarbonate into urea.
• Disorders related to urea cycle are rare.
Q3. Dx and Treatment?

8. Urea Cycle Disorders

9. Enzyme Deficiencies of Carbohydrate
metabolism
Q4. Differences in
Glycogen storage
diseases

10. Glycogen storage diseases

11. Steroid Metabolism
Enzyme Deficiencies
Q5. Features of Congenital
adrenal hyperplasia.
Q6. Familial hypercholestrolemia?

12. Lipid Synthesis
Enzyme Disorders

13. Lysosomal Storage Disease

14. Lysosomal Enzyme Deficiencies
Enzyme Deficiencies

15. Lysosomal Enzyme Deficiencies
Enzyme Deficiencies

16. Enzyme Deficiencies of purine
metabolism
Q7. Features of ADA deficiency.
Gene therapy for ADA?

17. Enzyme Deficiencies
Copper metabolism
Q8. Features of WD?

18. Enzyme Deficiencies
Q9. Role of peroxisome?
Q10. Features of Zellweger
syndrome?
Q11. Features of
Adrenoleukodystropy?

19. Enzyme Deficiencies

20. Questions?