Blood Brown Haemoglobinopathies Flashcards
(21 cards)
What are haemoglobinopathies?
Disorders of haemoglobin, among the most common Mendelian disorders affecting ~0.5 million people per year.
What is the primary mutation associated with sickle cell disease?
HbS (sickle cell variant).
What are the three types of thalassemia?
- Major (no product)
- Intermedia (reduced but variable amount)
- Minor or trait (carriers)
What is the life expectancy of untreated thalassemia major?
Less than 5 years.
What treatment is required for iron overload due to blood transfusions in thalassemia?
Chelation therapy.
What is the cure for thalassemia?
Bone marrow (stem cell) transplant.
What is the role of hydroxyurea in thalassemia treatment?
It increases expression of fetal hemoglobin (γ).
What new gene editing technology was approved in 2023 for treating thalassemia?
CRISPR gene editing.
What is the inheritance pattern of β-thalassemia?
Autosomal recessive.
What is allelic heterogeneity?
The occurrence of more than one allele at a locus.
What is locus heterogeneity?
The association of more than one locus (gene) with a clinical phenotype.
What is the benefit of being a carrier of thalassemia in certain ethnic groups?
Decreased risk of malaria in children.
Fill in the blank: Thalassemia carriers have a detectable _______ but no clinical disease.
microcytic anaemia.
What is the typical genetic status of alpha-thalassemia carriers?
Two or three copies of the alpha gene.
What are the complications of blood transfusions in thalassemia patients?
Iron overload.
What are the two main types of mutations affecting globin function?
- Decreased/Loss of function
- Abnormal/gain of function.
What is the effect of the BCL11A transcription factor?
It represses the switch from γ to β globin after birth.
True or False: Genetic disorders may be treated by different strategies.
True.
What public health approach can help prevent beta-thalassemia?
Population screening for carriers.
What ethical issue is associated with genetic testing in developing countries?
Autonomy and informed consent.
What is a potential alternative to managing thalassemia in prenatal settings?
Prenatal/genetic screening for affected fetus with termination option.
