enzymeopathies Flashcards
name the enzymopathies
G6PD Deficiency
Pyruvate Kinase Deficiency
clinical features G6PD
- Clinical Features: Neonatal Jaundice (Without anaemia, with severe Haemolysis) Chronic non-spherocytic Haemolytic Anaemia Favisim + Drug-Induced Crisis (Primaquine, Rasburicase, Methylene Blue, Dapsone, Quinine, Septrin, Nitrofurantoin) Haemolysis is DAT negative and Intravascular
investigations G6PD
DAT Negative + Features of Haemolysis
Bite + Blister Cells
Screening and Quantification Testing (False Negatives in Active Haemolysis, Deficiency not pronounced in retics)
management G6PD
Hydration Transfusion Splenectomy
genes G6PD
x linjked
pyrivate kinase def pathology and genetics
- Autosomal Recessive (PKLR Gene)- Pyruvate Kinase dominant controller of cellular glucose metabolism allowing for Pyruvate and ATP generation- Deficiency leads to increase in 2,3-DPG amongst other metabolites which interfere with metabolism and lifespan
pyruvate kinase def clinical features
IUGR, Hydrops Fetalis, Prematurity Neonatal Jaundice +/- Blueberry Muffin Rash Chronic Haemolytic Anaemia Jaundice / Splenomegaly / Gallstones Hyperpigmentation / Ulcers /Pulmonary Hypertension / Extramedullary haematopoeisis
pyruvate kinase def and investigations
Genetics Spectrophotometry Assay of Red Cell Lysate (FN if contaminated with WCC/Platelets) Film: Haemolytic Picture, Heinz Body’s, Acanthocytes/Irregularly contracted cells
pyruvate kinase def management
Tranfusion Dependent +/- Iron Chelation Splenectomy Allo SCT Oral PK Activator
Diagnosis of G6PDH deficiency (3)
FBC + blood film
- Normal inbetween attacks
- Attack: normocytic, normochromic, increased reticulocytes, heinz bodies and bite cells
Low G6PDH levels
Risk factors for G6PDH deficiency (2)
- X-linked recessive (men)
- West African, Mediterranean, Asian
Factors that can precipitate G6PDH deficiency (5)
- Naphthelene (in moth balls (pesticide))
- Antimalarials, eg: quinine
- Aspirin
- Fava beans (contain glucosides that can be oxidised into ROS)
- Nitrofurantoin
What is a G6PDH attack?
Rapid anaemia + jaundice (intravascular haemolysis)
What is G6PDH? (3)
- Glucose-6-phosphate dehydrogenase
- Protects RBCs from vasoxidative damage
- Involved in glutathione synthesis (protects from ROS like H2O2)
What is G6PDH deficiency (2)
- X linked recessive enzymopathy
- Causes 1/2 lifespan + RBC degeneration
