The most unknown inomilies in medical hiistory

Exposure to thalidomide during the critical period (days 23 to 28 of gestation) results in a number of defects, the most notable of which are limb defects ranging from triphalangeal thumb to tetra-amelia or phocomelia of the upper and lower limbs, at times with preaxial polydactyly of six or seven toes per foot. Thalidomide, a drug once used in the treatment of morning sickness, was first recognized as a teratogen by Lenz and McBride in separate reports in 1961. For help with these latter matters, the reader is referred to chapters that cover specific organ systems. As such, descriptions will emphasize gross features over microscopic appearances or discussions of intricate pathologic processes. The purpose of this chapter, then, is to provide a broad context for understanding the basic patterns of anomalies. It can fall to the pathologist, as well as clinical specialists, to help explain these findings.

But if these issues continue to hamper our dealings professionally, they also tug at the souls of grieving parents who ask вЂњWhat caused my babyвЂ™s problem?вЂќ or вЂњHow did this happen?вЂќ or вЂњWill it happen again?вЂќ These questions take on added complexity when multiple anomalies are encountered in a single patient. In fact, only 30 to 40 exogenous substances (i.e., teratogens) have been proven to have this potential. Another common, but erroneous, opinion is that hundreds or even thousands of substances in the environment cause birth defects. In fact, this is often not the case, for many congenital anomalies are neither genetic in origin nor do they constitute a physical deformation per se. In many circles, for example, the statement that вЂњthe baby was born with a genetic deformityвЂќ is often heard.

The study of congenital anomalies continues to be hampered by misunderstandings at a number of levels.

The most unknown inomilies in medical hiistory