Which one of the following disorder is inherited in an Autosomal Dominant manner?
High-Yield Explanation
Hereditary spherocytosis is a disorder inherited in an autosomal dominant manner. The hallmark feature of HS erythrocytes is loss of membrane surface area relative to intracellular volume, resulting in the spheroidal shape and decreased deformability of the red cell. Loss of erythrocyte surface area results from increased membrane fragility caused by defects in proteins of the erythrocyte membrane, such ankyrin, band 3, beta-spectrin, alpha-spectrin, and protein 4.2. Children mostly present with features of anemia, and on examinations shows jaundice, splenomegaly. Investigation:Peripheral smear shows spherocytes lacking central pallor, less commonly anisocytosis and poikolocytosis are noted. CBC shows mild to moderate anemia, normal MCV, increased MCHC, increased RDW and Osmotic fragility test is positive. Ref: Harrison's Principle of Internal Medicine, 16th Edition, Pages 501, 875, 878, 2147; William Hematology, 8th Edition, Chapter 45 ; Blueprints Pediatrics By Bradley S. Marino, 5th Edition, Pages 108-9