Congenital malformations

Syndromes of multiple congenital abnormalities often have
mendelian, chromosomal or teratogenic causes, many of which
can be identified by modern cytogenetic and DNA techniques.
Some malformations are non-genetic, such as the amputations
caused by amniotic bands after early rupture of the amnion.
Most isolated congenital malformations, however, follow
multifactorial inheritance and the risk of recurrence depends
on the specific malformation, its severity and the number of
affected people in the family. Decisions to have further
children will be influenced by the fact that the risk of
recurrence is generally low and that surgery for many isolated
congenital malformations is successful. Prenatal
ultrasonography may identify abnormalities requiring
emergency neonatal surgery or severe malformations that have
a poor prognosis, but it usually gives reassurance about the
normality of a subsequent pregnancy.