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 Supernumerary body part Supernumerary body parts are most commonly a congenital disorder involving the growth of an additional part of the body and a deviation from the body plan. Body parts may be easily visible or hidden away, such as internal organs. Many additional body parts form by the same process as conjoined twins: the zygote begins to split but fails to completely separate. This condition may also be a symptom of repeated occurrences of continuous inbreeding in a genetic line. Specific types of additional body parts include: Vestigial structures are anatomical structures of organisms in a species which are