My son is 14 years old. He had a huge growth spurt this spring and summer and passed my husband up in height. He is now 5 11 . He started developing stretch marks several months ago on his shoulder blade and around his side under his one arm. I thought he was twisting himself up in his blanket at night, but when they didn t go away I looked closer and they are stretch marks. Now he has suddenly developed deeper red stretch marks in the center of his back on his spine. I am concerned about something called Marfans syndrome after searching the internet because my son is taller than any person in either my husband s or my family. We have no idea where his height comes from. He has extremely long fingers and his breast bone sinks in a bit in the middle. He also has very large feet. The last pair we bought him were size 13s. I don t know if I should let it go as him growing so fast, which he did. Or be worried and schedule all sorts of tests for some syndrome I saw on the Internet. :(