Repeat T3 as Free T3 otherwise thyroid looks fine. Also check thyroid antibodies esp given dad's history.
I would suggest going to a good endo that deals a lot with adrenals and thyroid issues and futher testing done with antibodies, etc. Bring copy of last thyroid test but endo might want to do her/his own test. Your sons thyroid test might suggest Chronic illness, starvation/nurtition/Selenium deficiency/ Potassium and Zinc deficiency/Low protein intake/poor protein digestion/ prolonged intake of refined carbohydrates and sweets, medications such as Inderal, steriods and amiodarone, Compromised liver or kidney function, Cadmium, mercury and lead toxicity, T-4 T-3 conversion problem/Reverse T-3 (Dominance), or hypo/hashi. Mean while have son get plenty of rest, eliminating as much emotional stress as possible, moderate exercise for stress control, and eating a well balanced diet.