{{Short description|Physical abnormality in a living organism}} {{multiple issues| {{one source|date=March 2012}} {{Citations missing|date=April 2008}} }} [[File:Chinese circus performer with craniosynostosis, 1927.jpg|thumb|Chinese circus performer with craniosynostosis, 1927]] [[Image:Octopus-sucker-deformity.jpg|thumb|220px|A deformed sucker cluster on an arm of an octopus]]
A '''deformity''', '''dysmorphism''', or '''dysmorphic feature''' is a major abnormality of an organism that makes a part of the body appear or function differently than how it is supposed to.
==Causes== Deformity can be caused by a variety of factors: *Arthritis and other rheumatoid disorders *Chronic application of external forces, e.g. artificial cranial deformation *Chronic paresis, paralysis or muscle imbalance, especially in children, e.g. due to poliomyelitis or cerebral palsy *Complications at birth *Damage to the fetus or uterus *Fractured bones left to heal without being properly set (malunion) *Genetic mutation *Growth or hormone disorders *Skin disorders *Reconstructive surgery following a severe injury, e.g. burn injury *Mutilation
Deformity can occur in all organisms:
* Frogs can be mutated due to ''Ribeiroia'' (Trematoda) infection. * Plants can undergo irreversible cell deformation<ref>{{cite journal | vauthors = Lockhart JA | title = Physical nature of irreversible deformation of plant cells | journal = Plant Physiology | volume = 42 | issue = 11 | pages = 1545–1552 | date = November 1967 | pmid = 16656691 | pmc = 1086764 | doi = 10.1104/pp.42.11.1545 }}</ref> * Insects, such as honeybees, can be affected by deformed wing virus * Fish can be found with scoliosis due to environmental factors<ref>{{Cite web |title=Body Deformities | work = Regional Aquatics Monitoring Program (RAMP) | publisher = Alberta Environment and Parks Environmental Monitoring and Science Division |url=http://www.ramp-alberta.org/ramp/community/abnormalities/what/deformities.aspx |access-date=2022-03-19 }}</ref>
==Mortality== thumb|Case of acephalus holoacardiacus – born without a head. Was birthed alongside a healthy twin.<ref>{{Cite journal |vauthors = Boulgakow B |date=1926 |title="Arrest of Development of an Embryo. A Case of Acephalus Holoacardiacus showing Arrest of Development of all Tissues in Embryonic Period." |journal=Journal of Anatomy |volume=61 |issue=Pt 1 |pages=68–93|pmid=17104128 |pmc=1249928 }}</ref>
In many cases where a major deformity is present at birth, it is the result of an underlying condition severe enough that the baby does not survive very long. The mortality of severely deformed births may be due to a range of complications including missing or non-functioning vital organs, structural defects that prevent necessary function, high susceptibility to injuries, abnormal facial appearance, or infections that eventually lead to death.
In some cases, such as that of twins, one fetus is brought to term healthy, while the other faces major, even life-threatening defects. An example of this is seen in cattle, referred to as amorphous globosus.
Deformities with mortality (Incompatible with life):
Neural tube defects:
* Anencephaly * Iniencephaly * Craniorachischisis
* Phocomelia (50% chance of death in some infants due to respiratory distress) * Sirenomelia * Limb body wall complex * Thanatophoric dysplasia * Achondrogenesis
Facial deformities:
* Cyclopia * Otocephaly
Twinning:
* TRAPS Sequence (Depending on the size of the acardiac twin is the risk of death of the pump twin) * Cephalothoracopagus * Parasitic twin (Parasite) Genetic disorders:
* Aneuploidies (Trisomy 13, 16, 18, Monosomy 14) * Triploidy * Harlequin ichthyosis * Schinzel-Giedion syndrome * Raine syndrome * Pfeiffer syndrome (Type 3 or most frequently, 2) * Melnick-Needles syndrome in males
==In mythology== There are many instances of mythological characters showing signs of a deformity.
* Descriptions of mermaids may be related to the symptoms of sirenomelia. * The Irish mythology includes the Fomorians, who are almost without exception described as being deformed, possessing only one of what most have two (eyes, arms, legs, etc.) or having larger than normal limbs. * Hephaestus, of Greek Mythology, was born with a club foot.<ref name=":0">{{Cite journal | vauthors = Bazopoulou-Kyrkanidou E |date=1997-10-17 |title=What makes Hephaestus lame? |journal=American Journal of Medical Genetics |language=en |volume=72 |issue=2 |pages=144–155 |doi=10.1002/(SICI)1096-8628(19971017)72:2<144::AID-AJMG5>3.0.CO;2-V|pmid=9382134 }}</ref>
== See also == {{Commonscat|Congenital diseases and disorders|Deformity}} *Birth defect *Body dysmorphic disorder *Congenital abnormality *Disfigurement *Genetic variation *Malformation *Monstrous birth *Phocomelia *Polymelia *Teratology
== References == {{Reflist}}
== Further reading == {{refbegin}} * {{cite encyclopedia | vauthors = Hogan CM | date = 2010 | url = http://www.eoearth.org/article/Mutation?topic=49496 | title = Mutation | veditors = Monosson E, Cleveland CJ | encyclopedia = Encyclopedia of Earth | publisher = National Council for Science and the Environment. | location = Washington DC | archive-url = https://web.archive.org/web/20110430051516/http://www.eoearth.org/article/Mutation?topic=49496 | archive-date = 2011-04-30 }} {{refend}}
{{Nutritional pathology}} {{Authority control}} Category:Human physical appearance Category:Anatomy Category:Developmental biology