Neural tube defects can be diagnosed during pregnancy. Although the condition can run in families, the responsible genes have not yet been identified. Bipolar disorder is probably due to the interaction of many different genes. But the genetics of most cancers are not well understood. May be due to chromosomal rearrangements, mutation in individual genes, to environmental insult, or to combinations of factors.
Some forms are attributable to environmental insult such as thalidomide ingested during pregnancy.
This causes ambiguous external genitalia in females. A more severe form of the disease causes salt loss and can lead to death in newborn infants. The defect, caused by mutation of a recessive gene on chromosome 6p, can be treated in utero. Some forms are attributable to environmental insults such as rubella and to maternal diabetes. Multiple causes that may include genetic predisposition.