Prader-Willi+syndrome

=Prader-Willi syndrome=

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 * Name of disease **: Prader-Willi syndrome


 * Cause of disease **: This disease is caused by the lack of paternal copies of genes on chromosome 15 due to deletion, imprinting defect, or having two copies of the maternal genes, which are silent due to epigenetic gene expression (Cassidy et al. 2012).


 * Historical background **: Langdon-Down described symptoms of a girl with Prader-Willi syndrome in 1887 and called it “polysarcia” (Ledbetter et al. 1981). In 1957, Prader and other researchers found a variety of other patients with symptoms similar to what Langdon-Down reported, and Ledbetter et al. (1981) found that the syndrome was caused by mutations of chromosome 15.


 * Symptoms **: When patients are infants, they commonly exhibit a lower birth weight, difficulty waking up, weak cry and suck, and slow movements (Cassidy et al. 2012). Later in life, patients will show delayed cognitive development, learning disabilities, and low IQ (Cassidy et al. 2012). A characteristic symptom is the inability to feel full, which leads to morbid obesity and associated diseases such as diabetes (Cassidy et al. 2012). Physical features commonly exhibited are almond-shaped eyes, narrow noses, narrow forehead, slender hands, short stature and incomplete sexual development (Cassidy et al. 2012). Infertility is also common as well as behavioral disorders and sleep abnormalities (Cassidy et al. 2012).

 Infants: Specialized feeding strategies, testosterone therapy and growth hormone replacement therapy (Cassidy et al. 2012). Diagnosis and preventative strategies early in life can prevent obesity (Cassidy et al. 2012).  Children: Strict supervision of food intake, growth hormone replacement therapy, speech therapy, sleep disturbance therapy (Cassidy et al. 2012).  Teens and Adolescents: Continuance of growth hormone replacement therapy, continuance of food intake supervision, sex hormone replacement therapy, daily muscle training and exercise (Cassidy et al. 2012).
 * Treatments **:


 * Current research **: Resnick et al. (2013) described the use of animal models to understand the genetic mechanisms associated with Prader-Willi syndrome, and discover their functions. The goal is to maximize the efficiency of the animal models used in order to better understand this disease, and identify new possible treatments targeting the epigenetics of the disease.

**<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">REFERENCES **


 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Cassidy SB, Schwartz S, Miller JL, Driscoll DJ **<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">(2012) Prader-Willi syndrome. Genet Med **14**: 10-26


 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Ledbetter DH, Riccardi VM, Airhart SD, Strobel RJ, Keenan BS, Crawford JD **<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">(1981) Deletions of chromosome 15 as a cause of Prader-Willi syndrome. N Engl J Med **304(6)**: 325


 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Resnick JL, Nicholls RD, Wevrick R **<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">(2013) Recommendations for the investigationg of animal models of Prader-Willi syndrome. Mamm Genome **24**: 165-178