Review Question - QID 213879

A 3-year-old boy is brought to the pediatrician’s office by his parents due to concerns for leg pain at night. The mother states that for the past several months, the boy has complained of intermittent pain in his legs, which tends to occur at night. The family has had to go to their local urgent care for pain control on 2 occasions. Otherwise, the boy has been feeding normally; however, the mother believes that he has not been gaining weight appropriately. On exam, the patient’s temperature is 98.4°F (36.9°C), blood pressure is 102/70 mmHg, pulse is 84/min, and respirations are 14/min. The boy is interacting appropriately for his age and can speak in short sentences. On his last visit 6 months prior, he was at the 30th percentile for weight and is now at the 15th percentile. The patient has a palpable spleen 2 cm below the costal margin, without tenderness to palpation. A mutational analysis is performed, and a cell analysis demonstrates glycolipid accumulation in macrophages. The patient is started on the appropriate enzyme replacement therapy. Neither parent is affected by the disease, and they are concerned about their chances of having another child with this disease. Which of the following is the most likely estimate of this probability?