Biochemical Genetics

Medical Genetics

MPH2-1-15

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.

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.

Enzyme Deficiencies

Q1. D/D of HomocystinuriaQ2. Dx and Treatment if any?

Sites of Enzyme Deficiencies

Enzymes Involved in Phenylalanine metabolism and deficiency states

Urea Cycle DisordersEnzyme 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?

Urea Cycle Disorders

Enzyme Deficiencies of Carbohydrate metabolism

Q4. Differences in Glycogen storage diseases

Glycogen storage diseases

Steroid MetabolismEnzyme Deficiencies

Q5. Features of Congenital adrenal hyperplasia.Q6. Familial hypercholestrolemia?

Lipid SynthesisEnzyme Disorders

Lysosomal Storage Disease

Lysosomal Enzyme DeficienciesEnzyme Deficiencies

Lysosomal Enzyme DeficienciesEnzyme Deficiencies

Enzyme Deficiencies of purine metabolism

Q7. Features of ADA deficiency. Gene therapy for ADA?

Enzyme DeficienciesCopper metabolism

Q8. Features of WD?

Enzyme Deficiencies

Q9. Role of peroxisome?Q10. Features of Zellwegersyndrome?Q11. Features of Adrenoleukodystropy?

Enzyme Deficiencies

Questions?