Case report: a rare case of concomitant haemophilia a and sickle cell disease

Abstract

Co-existing haemophilia A and sickle cell disease is rarely reported in the medical literature.1 Haemophilia A, an X-linked recessive bleeding disorder due to reduced factor VIII levels, has a reported incidence of 1:10,000 males globally.1 Sickle cell disease (SCD), an autosomal recessive disorder with abnormal haemoglobin production (HbS), affects 20–25 million people globally.1 This case presentation describes a rare presentation of haemophilia A and SCD in a 4-year-old male recently immigrated from Uganda, who presented with a four day history of a painful right knee and background of easy bruising and bleeding. Clinical examination was consistent with haemarthrosis. Initial screening bloods demonstrated Hb 85 g/L, MCV 88 fL, WCC 19×109/L and Plt 518×109/L. Peripheral blood film examination demonstrated numerous sickle cells and target cells. Haemoglobin variant studies performed by HPLC demonstrated an elevated HbA2 (4.5%), elevated HbF (14.2%) and HbS (80%) consistent with SCD. Given clinical history and haemarthrosis, coagulation screening was performed which demonstrated an INR 1.2 and APTT 89 s. Factor VIII levels were greatly reduced at 1% (reference range 50–165%), consistent with haemophilia A. This case highlights the need for clinical correlation when interpreting laboratory findings as not all pain episodes in SCD are consistent with vaso-occlusive crisis.