Glaucoma and Greenland. Positive family history is a risk factor for glaucoma. The relative risk of having primary open-angle glaucoma (P.O.A.G.) is increased about two- to four-fold for people who have a sibling with glaucoma. Glaucoma, particularly primary open-angle glaucoma, is associated with mutations in several genes, including "MYOC, ASB10, WDR36, NTF4", "TBK1", and "RPGRIP1", although most cases of glaucoma do not involve these genetic mutations. Normal-tension glaucoma, which comprises one-third of POAG, is also associated with genetic mutations (including "OPA1" and "OPTN" genes). Various rare congenital/genetic eye malformations are associated with glaucoma. Occasionally, failure of the normal third-trimester gestational atrophy
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