The Prader-Willi syndrome (PWS) is due to the lack of expression of paternal genes of the 15q11-q13 region. It usually occurs sporadically, although some family cases have been described (<1%). Approximately 70% of cases are produced by deletions of paternal origin in the 15q11-q13 region. 28% of cases are due to maternal uniparental disomy and less than 2% are caused by imprinting alterations. A geneticist studying prader-willi syndrome should focus on chromosome 15, its structure or changes in the number, these anomalies are also related to other syndromes such as: Bloom Syndrome, Breast cancer, Isovaleric acidity among others.
Prader-Willi syndrome (PWS) is a rare genetic disorder characterized by hypothalamic-pituitary dysfunction associated with major hypotonia during the neonatal period and the first two years of life. From childhood to adulthood, the main problems are the appearance of hyperphagia with the risk of morbid obesity, learning difficulties and behavioral problems, even major psychiatric disorders.
In this syndrome, the affected region (15q11-q13) is located on the long arm of chromosome 15. On chromosome 15 of paternal origin, the genes of the 15q11-q13 region are functional, whereas they do not fulfill their function on chromosome 15 of maternal origin (inactivation by methylation).
These are taxons of green algae and consists of both chlorophyll A and B. Chlorophtyas usually live in fresh water. These are able to produce their own food and thus form a mutual relationship with lichens to provide food to lichen and in response to which lichen provide raw material to chlorophytes for food production.
The human body has the ability to maintain a constant internal environment so that every organ function properly. Maintenance of a constant internal conditions is called homeostasis. For examples, a healthy human body functions optimum at normal temperature which is 37°C. If the body temperature increases well above 37°C, then by self-regulatory process, our body brings down temperature to the normal. This is homeostasis.
