What is the most likely diagnosis for an 8-month-old male presenting with hemarthrosis and hematuria?

The presence of hemarthrosis (bleeding into the joint) and hematuria (blood in urine) in an 8-month-old male strongly suggests a bleeding disorder, particularly one that is hereditary and associated with deficiencies in clotting factors.

In this context, hemophilia is characterized by a deficiency in specific clotting factors, most commonly factor VIII (hemophilia A) or factor IX (hemophilia B). These deficiencies lead to prolonged bleeding episodes, which can manifest as spontaneous bleeding into joints, known as hemarthrosis, and bleeding from the urinary tract, resulting in hematuria.

The age of the child and the symptoms presented support the diagnosis of hemophilia, as it typically appears in males due to its X-linked recessive inheritance pattern. In contrast, conditions like von Willebrand disease, while they can lead to bleeding, typically manifest with mucosal bleeding and are less likely to present solely with the severe manifestations seen here. Likewise, hemorrhagic disease of the newborn primarily affects neonates within the first few days of life, and thrombocytopenia does not directly correlate with the specific symptoms of hemarthrosis and hematuria.

Thus, given the child's age and the distinctive symptoms of joint and