Scoliosis polymorphisms in the "MATN1" gene (encoding for matrilin 1, cartilage matrix protein). Fifty-three single nucleotide polymorphism markers in the DNA that are significantly associated with adolescent idiopathic scoliosis were identified through a genome-wide association study. Adolescent idiopathic scoliosis has no clear causal agent, and is generally believed to be multifactorial. The prevalence of scoliosis is 1% to 2% among adolescents, but the likelihood of progression among adolescents with a Cobb angle less than 20° is about 10% to 20%. Congenital scoliosis can be attributed to a malformation of the spine during weeks three to six "in utero" due to a
Supernumerary body part considered to have lost much or all of their original function through evolution. These body parts can be classed as additional to the required functioning of the body. In human anatomy the vermiform appendix is sometimes classed as a vestigial remnant. Prosthesis is an artificial extension that replaces a body part, and cybernetics is the study of computer technology in relation to organisms which can include replacement or additional body parts. Body integrity identity disorder (BIID) is a psychiatric disorder in which a person thinks that they have one or more additional limbs than they should, despite having two arms