FRCPath Haem Part 1 MCQs-Gen Haem 486

A 27-year-old woman of African ancestry is found to have a persistent neutrophil count of 0.9 × 10⁹/L during routine blood tests. She is clinically well, with no history of recurrent or unusual infections. Haemoglobin and platelet counts are normal. There is no lymphadenopathy or splenomegaly.

Further investigations show:

• Blood film: normal neutrophil morphology

• CRP: normal

• HIV and hepatitis screen: negative

• ANA: negative

• Fya: negative

• Fyb: negative

She is not taking any medications associated with neutropenia.

Which of the following is the most likely explanation for her neutropenia?

A. Autoimmune destruction of neutrophils

B. Reduced granulopoiesis due to ACKR1 mutation

C. Duffy-null associated neutropenia due to homozygous ACKR1 variation

D. Cyclic neutropenia caused by an ELANE mutation

E. Increased neutrophil apoptosis caused by recurrent viral infection