Given benzocaine's association with rare methemoglobinemia, suspicion arose that benzocaine-induced methemoglobinemia might have caused the unexpected and concerning decline in oxygen saturation levels, The arterial blood gas (ABG) results revealed a methemoglobin level of 42.8% (normal 0-1.5%), while oxyhemoglobin was 56.1 % (normal 94-99%). The gene discussed is HBG2; the disease is methemoglobinemia.