Porphyrias are rare inherited metabolic disorders caused by deficiencies in enzymes involved in heme synthesis. This leads to accumulation of porphyrin pathway intermediates, causing a variety of diseases collectively called porphyrias. The most common type of acute porphyria is acute intermittent porphyria, which results from a deficiency of porphobilinogen deaminase, causing accumulation of uroporphyrinogen I. Symptoms include abdominal pain, neuropathy, and sensitivity to sunlight. Treatment involves intravenous heme administration to reduce accumulated intermediates.

1. PORPHYRIAS AND DISEASES OF AMINO
ACID METABOLISM
SABAPATHI. N

3. PORPHYRIAS
Accumulate in erythroid cells and bone marrow.
• Greek word –porphura meaning purple
Genetic defects in the biosynthesis of porphyrins
Lead to the accumulation of pathway intermediates
Causing a variety of diseases
[Collectively as PORPHYRIAS]

4. • The porphyrias are rare inherited (oroccasionally
acquired) metabolic disorders due to deficiencies of
enzymes in HEME synthesis
• PORPHYRINS are organic compounds with four pyrrole
rings.
• They are referred to as “PIGMENT OF LIFE”

9. Acute intermittent porphyria
• Deficiency of porphobilinogen deaminase
• Most common type of acute porphyria in most countries

10. • Results in an accumulation of uroporphyrinogen I
-Rarer porphyrias
• An abnormal isomer of a protoporphyrin precursor. This
• Compound stains - the urine red,
• Causes the teeth to fluoresce strongly in UV
light, and
• Sensitive to sunlight.
• Many individuals with this porphyria are anemic, heme↓
Rise to
the
vampire
Myths

11. Odontoporphyria

12. Treatment
• Treat acute porphyria attacks with hemin (intravenous
heme); 3-4 mg/kg/d for 3-5 days
• Thrombophlebitis is the major adverse effect.

13. DEFECT IN AMINO ACID CATABOLISM

14. Alkaptonuria and Phenylketonuria
• Result from Defects in Phenylalanine Degradation

15. Albinism
Defect - Tyrosine hyroxylase,

16. Maple syrup urine disease