MLA SB A Qu estion B an k
Sickle Cell Disease
50 single best answer questions — Domain 6: Conditions, Body system: Blood and Lymph
Based on the GMC Medical Licensing Assessment (MLA) content map — applicable from September 2026
,BLOOD AND LY MPH Question 1 of 50
Sickle Cell Disease Sickle cell disease: pathophysiology and genetics
A 6-year-old boy with sickle cell disease has genetic testing confirming homozygous HbSS. What is the underlying molecular abnormality
causing this condition?
A A translocation between chromosomes 9 and 22
B A single point mutation in the beta-globin gene, causing substitution of valine for glutamic acid at position 6 of the beta-globin chain
C A deletion of the entire beta-globin gene
D An expansion of a trinucleotide repeat within the beta-globin gene
E A deletion of all four alpha-globin genes
Select the single best answer.
,BLOOD AND LY MPH Question 1 of 50 — Answer
Sickle Cell Disease Sickle cell disease: pathophysiology and genetics
A 6-year-old boy with sickle cell disease has genetic testing confirming homozygous HbSS. What is the underlying molecular abnormality causing this condition?
A A translocation between chromosomes 9 and 22
B A single point mutation in the beta-globin gene, causing substitution of valine for glutamic acid at position 6 of the beta-globin chain ✓ Correct
C A deletion of the entire beta-globin gene
D An expansion of a trinucleotide repeat within the beta-globin gene
E A deletion of all four alpha-globin genes
EXPLANATION
Sickle cell disease results from a single point mutation in the beta-globin gene, causing substitution of valine for glutamic acid at position 6 of the beta-globin chain,
producing abnormal haemoglobin S.
, BLOOD AND LY MPH Question 2 of 50
Sickle Cell Disease Sickle cell disease: pathophysiology and genetics
A 30-year-old man with sickle cell disease is exposed to hypoxia during a long-haul flight and develops a painful crisis. What is the
underlying pathophysiological process linking hypoxia to his symptoms?
A Hypoxia has no relationship to sickle cell crises
B Hypoxia causes a sudden drop in platelet count, leading to bleeding
C Hypoxia directly destroys white blood cells, causing his symptoms
D Hypoxia causes increased production of normal haemoglobin, worsening symptoms
Deoxygenation causes polymerisation of haemoglobin S within red cells, distorting their shape into a sickle form and increasing blood viscosity,
E
leading to vaso-occlusion
Select the single best answer.
Sickle Cell Disease
50 single best answer questions — Domain 6: Conditions, Body system: Blood and Lymph
Based on the GMC Medical Licensing Assessment (MLA) content map — applicable from September 2026
,BLOOD AND LY MPH Question 1 of 50
Sickle Cell Disease Sickle cell disease: pathophysiology and genetics
A 6-year-old boy with sickle cell disease has genetic testing confirming homozygous HbSS. What is the underlying molecular abnormality
causing this condition?
A A translocation between chromosomes 9 and 22
B A single point mutation in the beta-globin gene, causing substitution of valine for glutamic acid at position 6 of the beta-globin chain
C A deletion of the entire beta-globin gene
D An expansion of a trinucleotide repeat within the beta-globin gene
E A deletion of all four alpha-globin genes
Select the single best answer.
,BLOOD AND LY MPH Question 1 of 50 — Answer
Sickle Cell Disease Sickle cell disease: pathophysiology and genetics
A 6-year-old boy with sickle cell disease has genetic testing confirming homozygous HbSS. What is the underlying molecular abnormality causing this condition?
A A translocation between chromosomes 9 and 22
B A single point mutation in the beta-globin gene, causing substitution of valine for glutamic acid at position 6 of the beta-globin chain ✓ Correct
C A deletion of the entire beta-globin gene
D An expansion of a trinucleotide repeat within the beta-globin gene
E A deletion of all four alpha-globin genes
EXPLANATION
Sickle cell disease results from a single point mutation in the beta-globin gene, causing substitution of valine for glutamic acid at position 6 of the beta-globin chain,
producing abnormal haemoglobin S.
, BLOOD AND LY MPH Question 2 of 50
Sickle Cell Disease Sickle cell disease: pathophysiology and genetics
A 30-year-old man with sickle cell disease is exposed to hypoxia during a long-haul flight and develops a painful crisis. What is the
underlying pathophysiological process linking hypoxia to his symptoms?
A Hypoxia has no relationship to sickle cell crises
B Hypoxia causes a sudden drop in platelet count, leading to bleeding
C Hypoxia directly destroys white blood cells, causing his symptoms
D Hypoxia causes increased production of normal haemoglobin, worsening symptoms
Deoxygenation causes polymerisation of haemoglobin S within red cells, distorting their shape into a sickle form and increasing blood viscosity,
E
leading to vaso-occlusion
Select the single best answer.
