Patients of Middle Eastern descent, such as the one presented in this manuscript, commonly harbor the Mediterranean G6PD variant, which can result in severe hemolysis. A wide spectrum of enzymatic deficiency has been described ranging from class I (severe, <10% of normal) to class IV (no enzyme deficiency or hemolysis). These reactions were subsequently found to correlate with reduced G6PD enzymatic activity in the red cells of affected individuals. It was first described in 1955 when it was noted that AfricanвЂ“American soldiers treated prophylactically with the antimalarial primaquine were more likely to develop jaundice and anemia than their Caucasian counterparts. It is an X-linked disorder that affects primarily males of African, Mediterranean and Middle Eastern ancestry. G6PD deficiency is the most common enzymatic disorder of red cells and affects >400 million people worldwide. He was commenced on atovaquone for PJP prophylaxis and was able to successfully complete his course of concomitant temozolomide and radiation treatment without further incident. His haptoglobin level and lactate dehydrogenase were also normalized. One month later, his G6PD level was measured at 0.8 U/g Hb (normal range: 4.6вЂ“13.5 U/g Hb). Due to concerns of G6PD deficiency, dapsone was discontinued. On questioning after admission to the hospital, his family remembered that he once had a reaction after eating fava beans over 50 years before as a child. He was transfused two units of packed red cells with improvement in his hemoglobin and hematocrit, and improvement in all symptoms except for his hemiparesis. His other laboratory evaluations included a negative stool guaiac test, an elevated lactate dehydrogenase 682 U/l (normal range: 120вЂ“220 U/l), normal direct bilirubin 0.4 mg/dl (normal range 0вЂ“0.4 mg/dl) and low haptoglobin <6 mg/dl (normal range: 36вЂ“195 mg/dl). However, in the emergency room, his hemoglobin was 7.8 g/dl and his hematocrit was 23.8%.

Prior to the initiation of therapy, his hemoglobin was 15.1 g/dl (normal range: 12вЂ“15 g/dl) and hematocrit was 43.5% (normal range: 36вЂ“46%).

He underwent an emergency computed tomography angiogram, which was negative for pulmonary embolism. He was seen in the emergency room during his second week of treatment complaining of a worsening hemiparesis as well as severe fatigue and was noted to have tachycardia, tachypnea and mild hypoxia in room air.

He was noted to be mildly thrombocytopenic at baseline and thus dapsone was chosen for Pneumocystis jirovecii pneumonia (PJP) prophylaxis rather than standard trimethoprim-sulfamethoxazole. He had an uneventful postoperative recovery and after evaluation by radiation and medical oncology, he was recommended to start standard concurrent radiation and temozolomide. He underwent subtotal resection of his frontal lesion, which was found to be an MGMT-unmethylated glioblastoma. His neurological examination was significant for left hemiparesis, and neuroimaging demonstrated numerous contrast enhancing masses in the right frontal and parietal lobes with extensive vasogenic edema and midline shift. A 62-year-old male of Egyptian origin presented with progressive left upper extremity weakness, headache, altered taste sensation and facial twitching.

Low hematocrit and hemoglobin pneumonia