Dysmelia (from the Greek (), "bad" + (), "limb" + English suffix -ia) is a

congenital disorder A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can ...

of a limb resulting from a disturbance in

embryonic development An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm ...

.(2006) Dysmelia (Limb Deficiency/Reduction). pp 312-322. In: Atlas of Genetic Diagnosis and Counseling. Humana Press.

Types

Dysmelia can refer to * missing ( aplasia) limbs: amelia,

oligodactyly Oligodactyly (from Ancient Greek ''oligos'' 'few' and δάκτυλος ''daktylos'' 'finger') is the presence of fewer than five fingers or toes on a hand or foot.

, congenital amputation e.g. tibial or radial aplasia *

malformation A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can r ...

of limbs: shortening (micromelia, rhizomelia or

mesomelia Mesomelia refers to conditions in which the middle parts of limbs are disproportionately short. When applied to skeletal dysplasias, mesomelic dwarfism describes generalised shortening of the forearms and lower legs. This is in contrast to rhizo ...

), ectrodactyly, phocomelia, meromelia, syndactyly,

brachydactyly Brachydactyly (Greek βραχύς = "short" plus δάκτυλος = "finger"), is a medical term which literally means "short finger". The shortness is relative to the length of other long bones and other parts of the body. Brachydactyly is an in ...

club foot Clubfoot is a birth defect where one or both feet are rotated inward and downward. Congenital clubfoot is the most common congenital malformation of the foot with an incidence of 1 per 1000 births. In approximately 50% of cases, clubfoot aff ...

* too many limbs: polymelia,

polydactyly Polydactyly or polydactylism (), also known as hyperdactyly, is an anomaly in humans and animals resulting in supernumerary fingers and/or toes. Polydactyly is the opposite of oligodactyly (fewer fingers or toes). Signs and symptoms In humans ...

polysyndactyly Polysyndactyly is a congenital anomaly, combining polydactyly and syndactyly, in which affected individuals have an extra finger or toe that is connected, via fusing or webbing, to an adjacent digit. __TOC__ Signs and symptoms Presentations o ...

* others: tetraamelia, hemimelia,

symbrachydactyly Symbrachydactyly is a congenital abnormality, characterized by limb anomalies consisting of brachydactyly, cutaneous syndactyly and global hypoplasia of the hand or foot. In many cases, bones will be missing from the fingers and some fingers or toes ...

Occurrence rate

Birth defects involving limbs occur in 1 per 1000.

Causes

Dysmelia can be caused by *

Inheritance Inheritance is the practice of receiving private property, Title (property), titles, debts, entitlements, Privilege (law), privileges, rights, and Law of obligations, obligations upon the death of an individual. The rules of inheritance differ ...

of abnormal

genes In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

, e.g.

, ectrodactyly or

, symptoms of deformed limbs then often occur in combination with other symptoms ( syndromes) * external causes during pregnancy (thus not inherited), e.g. via

amniotic band syndrome Constriction ring syndrome (CRS) is a congenital disorder with unknown cause. Because of the unknown cause there are many different, and sometimes incorrect names. It is a malformation due to intrauterine bands or rings that give deep grooves in, ...

teratogenic Teratology is the study of abnormalities of physiological development in organisms during their life span. It is a sub-discipline in medical genetics which focuses on the classification of congenital abnormalities in dysmorphology. The related t ...

drugs (e.g. thalidomide, which causes phocomelia) or environmental chemicals * ionizing radiation (

nuclear weapon A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both bom ...

s, radioiodine,

radiation therapy Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radia ...

) * infections * metabolic imbalance

Syndromes with dysmelia

* 2p15-16.1 microdeletion syndrome * Achard syndrome * Ackerman syndrome *

Acrocallosal syndrome Acrocallosal syndrome (also known as ACLS) is an extremely rare autosomal recessive syndrome characterized by corpus callosum agenesis, polydactyly, multiple dysmorphic features, motor and intellectual disabilities, and other symptoms. The syndrom ...

* Acropectoral syndrome *

Adams–Oliver syndrome Adams–Oliver syndrome (AOS) is a rare congenital disorder characterized by defects of the scalp and cranium (cutis aplasia congenita), transverse defects of the limbs, and mottling of the skin. Signs and symptoms Two key features of AOS are ...

Aglossia adactylia Hanhart syndrome (also known as Aglossia adactylia; Hypoglossia-hypodactylia syndrome; Peromelia with micrognathia; Jussieu syndrome) is a broadly classified medical condition consisting of congenital disorders that cause an undeveloped tongue an ...

Amniotic band syndrome Constriction ring syndrome (CRS) is a congenital disorder with unknown cause. Because of the unknown cause there are many different, and sometimes incorrect names. It is a malformation due to intrauterine bands or rings that give deep grooves in, ...

* Apert syndrome * Autosomal recessive Robinow syndrome * Basel–Vanagaite–Sirota syndrome (

Microlissencephaly Microlissencephaly (MLIS) is a rare congenital brain disorder that combines severe microcephaly (small head) with lissencephaly (smooth brain surface due to absent sulci and gyri). Microlissencephaly is a heterogeneous disorder, i.e. it has many d ...

- Micromelia syndrome) *

Campomelic dysplasia Campomelic dysplasia (CMD) is a genetic disorder characterized by bowing of the long bones and many other skeletal and extraskeletal features. It can be lethal in the neonatal period due to respiratory insufficiency, but the severity of the disease ...

* Cardiofaciocutaneous syndrome *

Catel–Manzke syndrome Catel–Manzke syndrome is a rare genetic disorder characterized by distinctive abnormalities of the index fingers; the classic features of Pierre Robin syndrome; occasionally with additional physical findings. Signs and symptoms The clinical pres ...

* Cenani–Lenz syndrome * Corneodermatoosseous syndrome * Diploid triploid mosaic *

Ectrodactyly–ectodermal dysplasia–cleft syndrome Ectrodactyly–ectodermal dysplasia–cleft syndrome, or EEC, and also referred to as EEC syndrome and split hand–split foot–ectodermal dysplasia–cleft syndromeFreedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ...

* Edwards syndrome * Ellis–Van Creveld syndrome * Fibular dimelia diplopodia syndrome (Leg duplication mirror foot syndrome) * Greig cephalopolysyndactyly syndrome * Haas syndrome *

Hanhart syndrome Hanhart syndrome (also known as Aglossia adactylia; Hypoglossia-hypodactylia syndrome; Peromelia with micrognathia; Jussieu syndrome) is a broadly classified medical condition consisting of congenital disorders that cause an undeveloped tongue an ...

Holt–Oram syndrome Holt–Oram syndrome (also called atrio-digital syndrome, atriodigital dysplasia, cardiac-limb syndrome, heart-hand syndrome type 1, HOS, ventriculo-radial syndrome) is an autosomal dominant disorder that affects bones in the arms and hands (the ...

* Humeroradial synostosis * Johnson–Munson syndrome *

Joubert syndrome Joubert syndrome is a rare autosomal recessive genetic disorder that affects the cerebellum, an area of the brain that controls balance and coordination. Joubert syndrome is one of the many genetic syndromes associated with syndromic retinitis pig ...

McKusick–Kaufman syndrome McKusick–Kaufman syndrome is a genetic condition associated with MKKS. The condition is named for Dr. Robert L. Kaufman and Victor McKusick. It is sometimes known by the abbreviation MKS. In infancy it can be difficult to distinguish between MK ...

Mermaid syndrome Sirenomelia, also called mermaid syndrome, is a rare congenital deformity in which the legs are fused together, giving the appearance of a mermaid's tail, hence the nickname. Classification Sirenomelia is classified by the skeletal structure ...

* Mesomelia-Synostoses syndrome (8q13 microdeletion syndrome) * Microgastria *

Myhre syndrome Myhre syndrome is a rare genetic disorder inherited in an autosomal dominant fashion. It is caused by mutation in SMAD4 gene. Signs and symptoms The clinical presentation is variable but includes * developmental and growth delay * athletic muscula ...

* Nager acrofacial dysostosis *

Neu–Laxova syndrome Neu–Laxova syndrome (NLS, also known as Neu syndrome; Neu-Povysilová syndrome; or 3-phosphoglycerate dehydrogenase deficiency, neonate form) is a rare autosomal recessive disorder characterized by severe intrauterine growth restriction and mu ...

* Patau syndrome *

Pfeiffer syndrome Pfeiffer syndrome is a rare genetic disorder characterized by the premature fusion of certain bones of the skull (craniosynostosis) which affects the shape of the head and face. In addition, the syndrome includes abnormalities of the hands (such ...

Poland syndrome Poland syndrome is a birth defect characterized by an underdeveloped chest muscle and short webbed fingers on one side of the body. There may also be short ribs, less fat, and breast and nipple abnormalities on the same side of the body. Typical ...

* Radial aplasia *

Roberts SC-Phocomelia syndrome Roberts syndrome, or sometimes called pseudothalidomide syndrome, is an extremely rare autosomal recessive genetic disorder that is characterized by mild to severe prenatal retardation or disruption of cell division, leading to malformation of th ...

(Phocomelia syndrome) *

Rubinstein–Taybi syndrome Rubinstein–Taybi syndrome (RTS) is a rare genetic condition characterized by short stature, moderate to severe learning difficulties, distinctive facial features, and broad thumbs and first toes. Other features of the disorder vary among affect ...

Silver–Russell syndrome Silver–Russell syndrome (SRS), also called Silver–Russell dwarfism, is a rare congenital growth disorder. In the United States it is usually referred to as Russell–Silver syndrome (RSS), and Silver–Russell syndrome elsewhere. It is one of ...

* Split-hand split-foot malformation (SHFM) *

TAR syndrome TAR syndrome (thrombocytopenia with absent radius) is a rare genetic disorder that is characterized by the absence of the radius bone in the forearm and a dramatically reduced platelet count. Signs and symptoms * Presents with symptoms of thro ...

(thrombocytopenia with absent radius) *

Tetra-amelia syndrome Tetra-amelia syndrome (''tetra-'' + '' amelia''), also called autosomal recessive tetraamelia, is an extremely rare autosomal recessive congenital disorder characterized by the absence of all four limbs. Other areas of the body are also affected b ...

Ulbright–Hodes syndrome Renal dysplasia-limb defects syndrome (RL syndrome), also known as Ulbright–Hodes syndrome, is a very rare autosomal recessive congenital disorder. It has been described in three infants, all of whom died shortly after birth. Presentation RL sy ...

* VACTERL association * Wallis–Zieff–Goldblatt syndrome

References

External links

DysNet: An organisation for people affected by Dysmelia (congenital limb difference)

Reach: Association for Children with Upper Limb Deficiency)
{{Congenital malformations and deformations of musculoskeletal system Congenital disorders of musculoskeletal system Supernumerary body parts