My son is almost 17. I work in the mental health field and yes, knew he had some "tactile" issues. We dealt with them when he was younger and call him "Monk-ish" now. He is brilliant (13th in a class of 400+). Yes, he has issues with noise, smells, textures and food. He also has lots of friends and is a good old-fashioned geek!
For those moms and dads who are worried, don't worry too much - help integrate different foods, textures, noises, etc... into your child's life. Recognize that each child is different and don't focus on the differences.
Yes, we look at the material and tag's on clothes before we buy and now that he shops for himself, he does too. How many of us have idiosyncrasies? I know I do. I cannot stand certain food textures and food to touch.
Did he learn this behavior or is it genetic? Who cares? He is a happy, well-adjusted, mac and cheese eating teenager who doesn't eat any chewy meat! Okay, so he smells the glass before he pours his milk. Strange? Yes.
He also washes his hands, a lot. He is healthy. Hang in there. Don't obsess and don't let the child know that you are upset by their behaviors.