![](https://upload.wikimedia.org/wikipedia/commons/thumb/0/02/Kiev-UkrainianNationalChernobylMuseum_15.jpg/220px-Kiev-UkrainianNationalChernobylMuseum_15.jpg)
Dysmelia (from the Greek dys (δυσ-), "bad" + mélos (μέλος), "limb" + English suffix -ia) is a congenital disorder of a limb resulting from a disturbance in embryonic development.[1]
Types
[edit]![](https://upload.wikimedia.org/wikipedia/commons/thumb/4/43/Feets_with_partial_simple_syndactyly.jpg/220px-Feets_with_partial_simple_syndactyly.jpg)
Dysmelia can refer to [citation needed]
- 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
![](https://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Polydactyly_ECS.jpg/220px-Polydactyly_ECS.jpg)
Occurrence rate
[edit]Birth defects involving limbs occur in 0.69 per 1000.[2]
Causes
[edit]Dysmelia can be caused by[citation needed]
- 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
[edit]- 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
[edit]- ^ "Dysmelia (Limb Deficiency/Reduction)". Atlas of Genetic Diagnosis and Counseling. Humana Press. 2006. pp. 312–322.
- ^ McGuirk, Caroline K.; Westgate, Marie-Noel; Holmes, Lewis B. (2001-10-01). "Limb Deficiencies in Newborn Infants". Pediatrics. 108 (4). American Academy of Pediatrics (AAP): e64. doi:10.1542/peds.108.4.e64. ISSN 1098-4275. PMID 11581472. S2CID 1863175.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction