Siamese Twinnings Essay, Research Paper

The etymology of term “siamese twins” can be attributedto Chang and Eng Bunker, the famous conjoined twins fromSiam who earned their living in the U.S. as a circusattraction in the Barnum and Baily Circus. They wereborn on May 11, 1811 in Siam and eventually made theirway to the United States where they earned a livingfirst as circus attractions and then as farmers.Scientists of the day argued over whether the brotherscould be successfully separated, since the twins joinedat the chest by a thick band of tissue. Twins joinedthis way can now be separated, but Chang and Eng did nothave 20th century technological advances at theirdisposal. Nevertheless, they lived long and fruitfullives until their death at age 63. Both married andfathered 21 children between them. Interestingly, 2 oftheir grand-daughters produced 2 normal sets of twins.However, the story of Chang and Eng is an exceptional

one, since so few conjoined twins survive beyondinfancy, let alone are born in the first place. Siamese twins are the result of a rare embryologicalaccident. The developing embryo begins to split intoidentical twins but then stops part way leaving thepartially separated egg to mature into a fetus. Mostconjoined twins are stillborn, and those that surviveoften die within a few hours. The frequency of the birthof conjoined twins is difficult to estimate, but perhaps5% of monozygotic (identical twin) twinnings fail toseparate completely and are conjoined. “According to Dr.Alan Guttmacher, noted physician and monozygotic twin,conjoined pairs are rarities which occur only once in50,000 to 80,000 births.” There is a great range in thedegree of fusion, and depending upon which organs areshared, some twins have undergone separation surgerywhere both have survived. Points of juncture can beentire torsos, the top or side of the cranium, hips,rear ends, chests.