Congenital amputation is the absence of a limb or part of a limb
at birth. There are different types of congenital amputation
birth defects. An infant with congenital amputation may be
missing an entire limb or just a portion of a limb. The complete
absence of a limb leaving a stump is called transverse
deficiency, or amelia. When a specific part of a limb is
missing, for example, when the fibula bone in the lower leg is
missing, but the rest of the leg is intact, it is called a
longitudinal deficiency. The condition in which only a mid-
portion of a limb is missing, as when the hands or feet are
attached directly to the trunk, is known as phocomelia.
Congenital amputation may be the result of the constriction of
fibrous bands within the membrane that surrounds the developing
fetus (amniotic band syndrome), the exposure to substances known
to cause birth defects (teratogenic agents), genetic factors, or
other, unknown, causes. An estimated one in 2,000 babies is born
with all or part of a limb missing. This nu