Interesting, so I decided to look up some research on somemedical sites for you: Good news: is that it is not a developmental delay. O.K. News: is that he may have teeth and skin issues in the future. See details below. Best news: You can use Biotin to enhance the hair cuticles to give him healthier hair.
I found this on healthmad.com: "Have you ever tried to painfully comb your hair and try to make it settle down or spent endlessly on hair gels, hairsprays, head scarfs and shampoos yet never managed to bring down your defiant springing curls? Good news for sufferers. Your culprit has been tracked recently by American scientists as reported by MSNBC, although Germans acknowledged this hair raising issue almost 150 years ago and the French termed it cheveux incoiffables, in 1973." It goes on to define UHS: "commonly known as Uncombable Hair Syndrome usually makes an appearance between 3 months to 12 years of age. It is also called "Pili trianguli et canaliculi" and "Spun glass hair." The hair fibre is inflexible, refusing to lie flat against the scalp and the result is brittle, coarse, straw-like textured hair which cannot be combed flat. Since hair is dependent on Keratin and is similar in its basic structure to teeth and nails, problems such as brittle nails and tooth enamel are part of the parcel."
Solution: "Since it is one of the eight essential vitamins that comprise the Vitamin B-complex, Biotin promotes hair growth and is essential for maintaining healthy hair. Also known as Vitamin H, Biotin is a natural resource offering a break from tangling and uncombable hair and Nutritionists believe that people with certain Biotin deficiencies tend to have dry, stringy and dull hair. However the good news is that you can deliver biotin to your hair in various easier methods other than through ingestion and/or injections. Commonly used in Shampoos and Conditioners, Biotin penetrates and expands the hair shaft resulting in thickening of the hair cuticle and new healthier, richer, combable hair.