You are in the final week of your elective at the Medical Genetics Clinic. Your preceptor is so impressed with your genetics prowess that she sends you to see the next patients alone. You walk into the examining room and introduce yourself to Mrs. Smith, who is a 37 year old accountant from Edmonton. Mrs. Smith has come to see you with her son, Nathan. This is what Mrs. Smith tells you: “Nathan is my first child. He is now 12 months old. He is a very happy and smiley baby. But, I was visiting with my friend, who also has a 12 months old baby, and I noticed that Nathan seemed different than my friend’s baby. This is my first child so I don’t know what’s normal or not. Nathan seems jittery and although he laughs a lot, he hasn’t said any words yet.”