A child is brought to your clinic with spontaneous bleeding into the joint. Investigations shows prolonged aPTT and decreased level of factor VIII. What is the likely inheritance pattern of this disease?
High-Yield Explanation
This child is suffering from Hemophilia which is an X linked recessive disorder. It leads to affected males and carrier females. Features of X linked recessive traits: Sons of women who are carriers have 50% chance of inheriting the disease, 50% daughters will also be carriers. All daughters of affected men are asymptomatic carriers, but sons of these men do not have the trait and cannot transmit it to their children. Examples of X linked recessive disorders are: Fragile X syndrome, Hemophilia A, B, Duchenne muscular dystrophy, G6PD deficiency, chronic granulomatous disease. Ref: Rubin's Pathology: Clinicopathologic Foundations of Medicine By Raphael Rubin, Page 215-6