Dysmelia (from the Greek (), "bad" + (), "limb" + English suffix -ia) is a congenital disorder of a limb resulting from a disturbance in embryonic development.
Types
Dysmelia can refer to
missing (aplasia) limbs: amelia, oligodactyly, congenital amputation e.g. tibial or radial aplasia malformation of limbs: shortening (micromelia, rhizomelia or mesomelia), ectrodactyly, phocomelia, meromelia, syndactyly, brachydactyly, club foot extra limbs: polymelia, polydactyly, polysyndactyly others: tetraamelia, hemimelia, symbrachydactyly
Occurrence rate
Birth defects involving limbs occur in 1 per 1000.
Causes
Dysmelia can be caused by
Inheritance of abnormal genes, e.g. polydactyly, ectrodactyly or brachydactyly, 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 teratogenic drugs (e.g. thalidomide, which causes phocomelia) or environmental chemicals ionizing radiation (nuclear weapons, radioiodine, radiation therapy) infections metabolic imbalance
Syndromes with dysmelia
2p15-16.1 microdeletion syndrome
Achard syndrome
Ackerman syndrome
Acrocallosal syndrome
Acropectoral syndrome
Adams–Oliver syndrome
Aglossia adactylia
Amniotic band syndrome
Apert syndrome
Autosomal recessive Robinow syndrome
Basel–Vanagaite–Sirota syndrome (Microlissencephaly-Micromelia syndrome) Campomelic dysplasia Cardiofaciocutaneous syndrome Catel–Manzke syndrome Cenani–Lenz syndrome Corneodermatoosseous syndrome Diploid triploid mosaic Ectrodactyly–ectodermal dysplasia–cleft syndrome Edwards syndrome Ellis–Van Creveld syndrome Fibular dimelia diplopodia syndrome (Leg duplication mirror foot syndrome) Greig cephalopolysyndactyly syndrome Haas syndrome Hanhart syndrome Holt–Oram syndrome Humeroradial synostosis Johnson–Munson syndrome Joubert syndrome McKusick–Kaufman syndrome Mermaid syndrome Mesomelia-Synostoses syndrome (8q13 microdeletion syndrome) Microgastria Myhre syndrome Nager acrofacial dysostosis Neu–Laxova syndrome Patau syndrome Pfeiffer syndrome Poland syndrome Radial aplasia Roberts SC-Phocomelia syndrome (Phocomelia syndrome) Rubinstein–Taybi syndrome Silver–Russell syndrome Split-hand split-foot malformation (SHFM) TAR syndrome (thrombocytopenia with absent radius) Tetra-amelia syndrome Ulbright–Hodes syndrome 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)