**Question:** All are seen in sickle cell anemia EXCEPT:

A. Pulmonary hypertension
B. Skin pigmentation disorders
C. Congenital heart block
D. Hemophilia

**Core Concept:** Sickle cell anemia (SCA) is a genetic disorder characterized by the production of abnormal hemoglobin (Hb) called Hb S, leading to red blood cells (RBCs) becoming rigid, crescent-shaped, and sticking to each other, causing organ damage and various complications.

**Why the Correct Answer is Right:** D. Hemophilia is a separate genetic disorder affecting blood clotting factors, rather than the structure and function of RBCs. Unlike SCA, hemophilia is characterized by prolonged bleeding episodes due to deficient clotting factors.

**Why Each Wrong Option is Incorrect:**

A. Pulmonary hypertension (PH) is a subset of primary pulmonary arterial hypertension (PAH), a condition characterized by increased pulmonary arterial resistance, leading to right heart failure. Sickle cell anemia itself does not directly cause PH; however, it can lead to secondary PAH due to end-organ damage, vaso-occlusive crisis, and hypoxia.

B. Skin pigmentation disorders are unrelated to sickle cell anemia. The correct answer should focus on anemia-related complications.

C. Congenital heart block is a rare complication of SCA, typically seen in newborns or infants, resulting from immune system reaction to fetal heart tissue. It is not a direct consequence of the underlying RBC abnormalities in SCA.

**Clinical Pearl:** Sickle cell anemia is a complex genetic disorder affecting RBCs and can lead to various clinical manifestations and complications. Understanding the distinction between primary and secondary causes of complications (e.g., pulmonary hypertension) is crucial for appropriate diagnosis and management.