Dysmelia

A dysmelia is a congenital malformation of one or more limbs, so the arms, hands, legs or feet. Are all four limbs affected, it is called Tetraamelia.

Etymology

The word derives from the Greek prefix δυς - ( dys -, corresponds German miss- or un - ) and μέλος Melos " link" from. Literally, therefore, means dysmelia a deformity of the limbs.

Molding

Malformations of the limbs can be:

• Complete absence: of limbs Amelie, fingers or toes Oligodactyly
• Absence of components such as the long bones in phocomelia, ectromelia
• Amputation stump like: Peromelie
• Shortenings of limbs: from fingers or toes brachydactyly, arms or legs Rhizomelie, Mesomelie, Akromelie
• Adhesions: from fingers or toes, syndactyly, polysyndactyly, ectrodactyly
• Too many links: Polymelia, polydactyly (a form of Polymelia )

Causes of non-genetic dysmelias

The causal factors for non-genetic dysmelias could be either the pregnant woman and the embryo infections or oxygen deficiency of the embryo, an amniotic band syndrome, or defect or deficiency diet of pregnant women. On the other hand, can be causes of dysmelia side effects of medications and hormone preparations. The most common example of drug side effects thalidomide (active ingredient of thalidomide ).

Heredity

If the dysmelia caused by external influences during pregnancy (eg, mechanically and the amniotic band syndrome), it is not inherited to the present state of science.

However, genetic defects such as the Holt -Oram syndrome, or TAR syndrome (thrombocytopenia absent radius) can cause malformations of the limbs. The gene defects are inherited, but must, if they are recessive, do not appear.

Diagnosis

A dysmelia can be seen in the context of prenatal diagnosis in utero by ultrasound fine.