What exactly is Phocomelia? How is it different than Roberts Syndrome?
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Roberts Syndrome is a very rare genetic disorder where at birth children have malformations of limbs, skull or facial region. These abnormalities can range from having none of the four limbs, missing smaller limbs, or limb reduction (a birth defect in which limbs of a fetus do not completely develop while in the utero).
A subdivision of this disorder is Phocomelia, an equally rare birth defect that causes abnormalities of the upper limbs (arms, hands, fingers). Often the bones may be extremely reduced or even gone. Because of the limited amount of people who have Phocomelia, the amount of knowledge about the disorder is very low. Phocomelia may be hereditary or be a result of sporadic gene changes, sporadic genetics being a genetic disorder that occurs for the first time in a family due to a new mutation or the like occurrence of a disorder that is not likely to recur in a family. Only 25% of pregnancies between two (recessive) carries of this disorder will show signs of Phocomelia. Despite thoughts that extreme radiation may have caused Phocomelia, the only other known cause of this disorder is Thalidomide, a chemical prescribed to pregnant women for their morning sickness.
A subdivision of this disorder is Phocomelia, an equally rare birth defect that causes abnormalities of the upper limbs (arms, hands, fingers). Often the bones may be extremely reduced or even gone. Because of the limited amount of people who have Phocomelia, the amount of knowledge about the disorder is very low. Phocomelia may be hereditary or be a result of sporadic gene changes, sporadic genetics being a genetic disorder that occurs for the first time in a family due to a new mutation or the like occurrence of a disorder that is not likely to recur in a family. Only 25% of pregnancies between two (recessive) carries of this disorder will show signs of Phocomelia. Despite thoughts that extreme radiation may have caused Phocomelia, the only other known cause of this disorder is Thalidomide, a chemical prescribed to pregnant women for their morning sickness.
What environmental factors can cause Phocomelia?
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In the 1950’s and 1960’s there was the Thalidomide Crisis. German scientists who created the drug Thalidomide distributed it all over Europe, Canada and South America. The drug was meant to help pregnant women with their morning sickness and pain, but instead cause major birth defects or in most cases Phocomelia. Although it is not known for sure, these birth defects are thought to be caused by an antihistaminic effect of Thalidomide as a derivative of glutamic acid (a non-essential amino acid). Out of all the children born, only 40% of children survived their birth with 50% of children having deformities whose mother took Thalidomide. A United States researcher noticed these traits and had Thalidomide banned in the United States due to the negative effects in Europe and lack of testing done on the drug.
The Chernobyl Radiation incident was once thought to have caused many deformities such as Phocomelia, but recent studies have shown that those cases (caused by radiation) are few and in between. An causes of Phocomelia that occurred during the same time period as Chernobyl is attributed to the use of Thalidomide.
The Chernobyl Radiation incident was once thought to have caused many deformities such as Phocomelia, but recent studies have shown that those cases (caused by radiation) are few and in between. An causes of Phocomelia that occurred during the same time period as Chernobyl is attributed to the use of Thalidomide.
Sources
"Roberts Syndrome." Roberts Syndrome. N.p., n.d. Web. 14 Oct. 2013. <http://children.webmd.com/roberts-syndrome>.
"Frances Oldham Kelsey: FDA Medical Reviewer Leaves Her Mark on History."Frances Oldham Kelsey: FDA Medical Reviewer Leaves Her Mark on History. N.p., n.d. Web. 16 Oct. 2013. <http://permanent.access.gpo.gov/lps1609/www.fda.gov/fdac/features/2001/201_kelsey.html>.
http://www.nytimes.com/2010/03/16/science/16limb.html?ref=science&pagewanted=all&_r=0
Walmsley, Katie. "26 Years On: Helping Chernobyl's Children." CNN. Cable News Network, 01 Jan. 1970. Web. 16 Oct. 2013. <http://www.cnn.com/2012/04/25/world/iyw-chernobyl-children/index.html>.
"Frances Oldham Kelsey: FDA Medical Reviewer Leaves Her Mark on History."Frances Oldham Kelsey: FDA Medical Reviewer Leaves Her Mark on History. N.p., n.d. Web. 16 Oct. 2013. <http://permanent.access.gpo.gov/lps1609/www.fda.gov/fdac/features/2001/201_kelsey.html>.
http://www.nytimes.com/2010/03/16/science/16limb.html?ref=science&pagewanted=all&_r=0
Walmsley, Katie. "26 Years On: Helping Chernobyl's Children." CNN. Cable News Network, 01 Jan. 1970. Web. 16 Oct. 2013. <http://www.cnn.com/2012/04/25/world/iyw-chernobyl-children/index.html>.