1. A young man recently died during surgery under general anesthesia. Symptoms prior to his death included muscle spasms, hyperthermia, acidosis, and cardiac arrest. His family history is significant for his father dying under similar conditions and an aunt having survived the same complications during a hip replacement surgery. He is survived by his wife, a son, and a daughter. DNA has been isolated from family members and a Southern blot of restriction fragments from a specific region of chromosome 19 reveals the following pattern: Which of the following conclusions can reasonably be drawn from these data?