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 can ...

of lacking one or more

limb Limb may refer to: Science and technology *Limb (anatomy), an appendage of a human or animal *Limb, a large or main branch of a tree *Limb, in astronomy, the curved edge of the apparent disk of a celestial body, e.g. lunar limb *Limb, in botany, ...

s. 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 Proto-oncogene protein Wnt-3 is a protein that in humans is encoded by the ''WNT3'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' ...

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.

Tetra-amelia 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 ...

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 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, 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 of ...

Management

A prosthesis can be given to compensate for the missing limb(s).

External links

2 kittens in same litter
born with complete

agenesis In medicine, agenesis () refers to the failure of an organ to develop during embryonic growth and development due to the absence of primordial tissue. Many forms of agenesis are referred to by individual names, depending on the organ affected: * A ...

of the back legs and pelvis
page with X-rays

References

External links

{{DEFAULTSORT:Amelia (Birth Defect) Congenital disorders of musculoskeletal system Congenital amputations

Symptoms

Description

Causes

Management

See also

External links

References

External links