Sirppisoluanemia

Sirppisoluanemia is a rare hereditary hemolytic anemia defined by chronic mild anemia with episodic hemolytic crises provoked by stressors such as infection, fever, or dehydration. It is associated with mutations in the SIRP1 gene, which encodes a membrane-cytoskeleton linker protein essential for maintaining erythrocyte membrane stability. The resulting red blood cells (RBCs) exhibit decreased deformability and increased fragility, particularly in the spleen.

Clinical presentation ranges from asymptomatic laboratory finding to fatigue, pallor, jaundice, and splenomegaly. Crises may include dark urine and acute anemia. Chronic hemolysis risks gallstone formation. Growth and exercise tolerance are usually preserved in milder cases, whereas severe transfusion-dependent disease can occur in some individuals.

Pathophysiology involves RBC membrane defects leading to spherocyte-like shapes and reduced surface-to-volume ratio, causing splenic sequestration and destruction. Laboratory studies show reticulocytosis and elevated indirect bilirubin. RBC membrane protein assays and genetic sequencing identifying SIRP1 mutations support diagnosis; osmotic fragility tests and flow cytometry for membrane proteins can aid in staging.

Diagnosis is supported by family history consistent with autosomal recessive inheritance. Management emphasizes supportive care: folic acid supplementation, regular monitoring, and transfusions during crises. In severe cases, splenectomy may reduce hemolysis but increases infection risk; appropriate vaccination and prophylactic antibiotics are advised. Prognosis varies with severity; most patients live normal lifespans with adequate management. The condition is exceedingly rare, with scattered cases reported worldwide.