Amelia is the
birth defect
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 ca ...
of lacking one or more
limbs. It can also result in a shrunken or deformed limb. The term may be modified to indicate the number of legs or arms missing at birth, such as tetra-amelia for the absence of all four limbs. A related term is
meromelia
Meromelia is a birth defect characterized by the lacking of a part, but not all, of one or more limbs with the presence of a hand or foot. It results in a shrunken and deformed extremity.
Cause
Such defects are mainly the results of genetic diso ...
, which is the partial absence of a limb or limbs. The term is from
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
ἀ- "lack of" plus μέλος (plural: μέλεα or μέλη) "limb"
Symptoms
The diagnosis of tetra-amelia syndrome is established clinically and can be made on routine prenatal ultrasonography.
WNT3 is the only gene known to be associated with tetra-amelia syndrome. Molecular genetic testing on a clinical basis can be used to diagnose the incidence of the syndrome. The mutation detection frequency is unknown as only a limited number of families have been studied. Affected infants are often stillborn or die shortly after birth.
Description
Amelia may be present as an isolated defect, but it is often associated with major malformations in other organ systems. These frequently include cleft lip and/or palate, body wall defects, malformed head, and defects of the neural tube, kidneys, and diaphragm. Facial clefts may be accompanied by other facial anomalies such as abnormally small jaw, and missing ears or nose. The body wall defects allow internal organs to protrude through the abdomen. Head malformations may be minor to severe with a near absence of the brain. The diaphragm may be herniated or absent and one or both kidneys may be small or absent.
Causes
Between 24 and 36 days after fertilization, development of limb(s) may be impeded. This may eventually lead to complete or partial absence of one or more than one limbs.
syndrome appears to have an autosomal recessive pattern of inheritance - that is, the parents of an individual with tetra-amelia syndrome each carry one copy of the mutated gene, but do not show signs and symptoms of the condition.
In a few cases, amelia may be attributed to health complications during the early stages of pregnancy, including infection, failed abortion or complications associated with removal of an IUD after pregnancy, or use of
teratogenic drugs, such as
thalidomide
Thalidomide, sold under the brand names Contergan and Thalomid among others, is a medication used to treat a number of cancers (including multiple myeloma), graft-versus-host disease, and a number of skin conditions including complications o ...
.
Management
A prosthesis can be given to compensate for the missing limb(s).
See also
*
Amniotic band constriction
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, ...
*
Dysmelia
*
Hemimelia
Hemimelia comprises the following:
* Fibular hemimelia, Congenital longitudinal deficiency of the fibula or fibular longitudinal meromelia
* Tibial hemimelia, Congenital longitudinal deficiency of the tibia, Congenital aplasia and dysplasia of t ...
*
Phocomelia
Phocomelia is a condition that involves malformations of human arms and legs. Although many factors can cause phocomelia, the prominent roots come from the use of the drug thalidomide scandal, thalidomide and from genes, genetic inheritance.
Occu ...
*
Thalidomide
Thalidomide, sold under the brand names Contergan and Thalomid among others, is a medication used to treat a number of cancers (including multiple myeloma), graft-versus-host disease, and a number of skin conditions including complications o ...
External links
2 kittens in same litterborn with complete
agenesis of the back legs and pelvis
page with X-rays
References
External links
{{DEFAULTSORT:Amelia (Birth Defect)
Congenital disorders of musculoskeletal system
Congenital amputations