Sorry, not right. Down's syndrome is a genetic disorder. Birth defects are often the result of a genetic problem, and there are many such types of disorders. Others, however, have non-genetic causes. This is environmental damage caused by alcohol ingested by the mother during gestation.
Birth defects are often the result of a genetic problem, and there are many such types of disorders.
Others, however, have non-genetic causes. Sorry, not right. This is a blood disorder which may have a genetic base. Sorry, not right. These broadly drawn developmental stages are quite stable landmarks.