Eyes on Ions

Question:  A 12 year old child is referred to you for progressive thyroid enlargement.  An ultrasound was obtained at an outside facility that shows multiple thyroid nodules, all benign appearing.  You notice that he has a cochlear implant and his parents remark that this was placed at 1 year of age.  What is the most likely diagnosis and mode of inheritance?  [Answer will be posted with next week's new question]

Answer to last week's question, "Chin Anesthesia" (November 14, 2016):

Mental nerve.  The second premolar tooth.