Spherocytosis is a common cause of inherited hemolytic anemia. The most likely cause for spherocytosis is

Correct Answer: B

Rationale: Rationale for Choice B: Defects in the peripheral proteins are the most likely cause of spherocytosis. Spherocytosis is characterized by spherical-shaped red blood cells due to a deficiency in peripheral membrane proteins like spectrin, leading to reduced cell flexibility and membrane stability. This results in premature destruction of red blood cells in the spleen, causing hemolytic anemia. Summary: A: Abnormal antigenic properties are not the primary cause of spherocytosis; the issue lies in membrane protein defects. C: Increased formation of ropalux is not a known factor in spherocytosis. D: Formation of sickle-shaped cells is characteristic of sickle cell anemia, not spherocytosis.

Correct Answer: C

Rationale: The correct answer is C, chronic myelocytic leukemia. The presence of increased numbers of neutrophils at various stages of maturation, along with increased basophils, eosinophils, and platelets, is characteristic of chronic myelocytic leukemia. This condition is marked by a myeloproliferative disorder, leading to an overproduction of myeloid cells in the bone marrow. Acute myeloid leukemia (choice A) typically presents with a high number of blast cells rather than mature neutrophils. Acute lymphoid leukemia (choice B) primarily involves lymphoid cells, not myeloid cells. Chronic lymphocytic leukemia (choice D) is characterized by the accumulation of mature lymphocytes, not myeloid cells as seen in this case.

Correct Answer: A

Rationale: Step 1: Visceral leishmaniasis is transmitted by sand flies. Step 2: In the Asian region, the main vector of visceral leishmaniasis is Phlebotomus species. Step 3: Phlebotomus species are known to transmit the Leishmania parasite in Asia. Step 4: Lutzomyia species are the main vector in the Americas. Step 5: Anopheles species are vectors for malaria, not leishmaniasis. Step 6: Mansonia species are vectors for diseases like filariasis, not leishmaniasis. Summary: Choice A is correct because Phlebotomus species are the main vector of visceral leishmaniasis in the Asian region, while choices B, C, and D are incorrect as they are not the main vectors for this disease in that specific geographical area.

Correct Answer: A

Rationale: The correct answer is A: vasculitis. Thalassemia major primarily causes abdominal pain due to complications such as splenic infarction, dragging pain from splenomegaly, and pigment stones in the gall bladder. Vasculitis is not a common complication of thalassemia major, making it the exception. Vasculitis is inflammation of blood vessels, not typically associated with abdominal pain in thalassemia. Therefore, A is the correct answer.

Correct Answer: A

Rationale: The correct answer is A because gum bleeding is not a characteristic of chronic phenytoin therapy. Phenytoin is used to treat seizures and does not directly cause gum bleeding. Aplastic anemia (B), scurvy (C), and hemophilia (D) are conditions that can lead to gum bleeding. Aplastic anemia is a bone marrow disorder, scurvy is a vitamin C deficiency, and hemophilia is a blood clotting disorder. Therefore, they are associated with gum bleeding.