The Genetic Disorder : Prader Willi Syndrome

This syndrome is from a mutation of a gene on chromosome 15 and this causes problems in the production of fibrillin-1 which is a protein that is an important part of connective tissue. The name for the gene is FBN1. Basically, it is the “glue” that helps to support the tissues in the human body. A child born to a parent with this syndrome has a 50% of having it. However, in the remaining 25%, neither parent has the disease which gives them a 1 in 10,000 chance of having a child with this disorder. When a child of two unaffected parents is born with it then the genetic mutation occurs in either the egg or sperm cell at the time of conception.

Prader-Willi and Angelman Syndrome are two genetic disorders with vastly differing phenotypes linked by missing genetic imprints on the 15th chromosome’s q arm between regions 11 and 13 . While both orders result in mental deficits, their symptoms are otherwise segregated from the other in their entirety. The differences in the disorders are the result of differing DNA methylation patterns present in maternally and paternally inherited DNA. If the deletion occurs in the mother’s DNA, then Prader-Willi Syndrome appears. When the deletion occurs in the father’s DNA, Angelman Syndrome is the result.

Williams Syndrome(WS) is considered as a neurodevelopmental disorder, caused by a contiguous gene deletion of about 26 genes from the long arm of chromosome 7(Peoples et al., 2000). Since it had been first aware by J.C.P. Williams in 1961(Lenhoff, Wang, Greenberg & Bellugi, 1997), Williams Syndrome has drawn more attention in last 40 years. the incidence rate is approximately 1 in 2000 and diagnosed generally at 6.4 years old (Morris, Demsey, Leonard, Dilts & Blackburn, 1988). People with WS usually show a developmental delay at the early age and are affected all life long. Williams Syndrome is characterised by some abnormalities in physical, behavioural, and cognitive.

Prader-Willi syndrome is a disorder that causes you to not feel satisfied with what you eat and not feeling full. This disorder affects many parts of the body. Prader -Willi syndrome is also very rare. Most people that have Prader – Willi syndrome then you most likely have type 2 diabetes. This is also a negative mutation.

While some inherited traits do not have significant effects on phenotypes, PPSH has a severe impact on physical appearance. The most significant effect on phenotype is the indistinguishable male genitalia. There have been three distinct phenotypic possibilities seen with PPSH in terms of sexual development. Some are born with ambiguous genitalia, which is difficult to determine the gender. Others have what appears to be male genitalia in the form of a micropenis while their urethra is on the other side of the penis. However, the most common phenotype in PPSH males is genitalia that appears female.

When the inheritance pattern is autosomal dominant, it means that one parent was affected and that one copy of the mutant gene will cause the disease. About 15-20% of RP cases are autosomal dominant (Chang, et al., 2011). On the other hand there is also the autosomal recessive inheritance. It takes two copies of the mutant genes to cause the disease. If both parents are carriers, there is a 1 in 4 chance of their child having RP, 1 in 2 chance that their child is a carrier, and a 1 in 4 chance that their child is not affected at all. In the case of a X-linked inheritance, male offspring are more susceptible to having the disease compared to female offspring who will most likely be carriers. However, about 40-50% of RP cases have been linked to unknown inheritance patterns (Chang, et al., 2011; Nash, et al.,

The disorder affects 1 out of 40,000 newborns (Atlas Genetics). Almost 90% of patients with this disease have a parent with the disease, but the symptoms in the parent can be very different from the symptoms in the child (MedlinePlus). Waardenburg syndrome type 1 (WS1) and type 2 (WS2) are inherited as autosomal dominant traits, which means one copy of the altered gene in each cell is sufficient to cause Waardenburg syndrome (GHR). Manifestations of the disorder may not be present in individuals that inherit the altered gene for the disease. Some cases of the disorder, such as type 3 (WS3) and type 4 (WS4) have an autosomal recessive pattern of inheritance. Type 1 and type 2 of Waardenburg syndrome can also be acquired even when there is no family history of the disorder. The disorder can be caused from new genetic changes that occur spontaneously for unknown reasons. Researches indicate that new sporadic mutations for type 1 of Waardenburg syndrome may be associated with the advanced age of the father. In dominant disorders, a single copy of the gene with the disease that is either received from the mother of father will be expressed in the offspring by dominating the other normal gene, which causes the result in the appearance of the syndrome (Rare

Since it does not affect nutrition and meal absorption at all, it is presumed not to impair children’s growth, while it provokes consistent weight reduction (Velhote et al., 2007).

Smith-Magenis Syndrome (SMS) is a chromosomal disorder due to the deletion of genetic material on chromosome 17, more specifically 17p11.2 (PEDNEUR). It is estimated that SMS occurs in about 1 in every 25,000 births, affects boys and girls equally, and is underdiagnosed because there’s not as much awareness about it compared to other disorders and syndromes (PRISMS). Therefore, the prevalence may be 1 in every 15,000 births, and most of the people with SMS have been identified in the last 5 to 10 years due to improved cytogenetic testing (PEDNEUR). SMS was first discovered by Ann C.M. Smith a genetic counselor, and Dr. R. Ellen Magenis a physician and chromosome expert in 1986 (PEDNEUR).

Williams syndrome is a rare, genetic disease affecting 1 out of 8,000 newborns (Williams syndrome, 2008). Caused by the deletion of several genes, there is no cure or treatment for it (Genetic Science Learning Center, 2014). While patients can live productive lives, they still face many difficulties in terms of their health and social skills.

Beckwith-Wiedemann syndrome is a pediatric overgrowth disorder involving a predisposition to tumor development. The average birth length, 52.6cm, the growth parallels curve at or above 95%, and average birth weight is 4kg. For the head there are a metopic ridge, large fontanel, and prominent occiput. There are also coarse facial features and midface hypoplasia. This also involves linear ear lobe creases, posterior helical indentations, prominent eyes, and macroglossia. For the skeleton, there is advanced bone age, most pronounced during first 4 years. Patient could also have nevus flammeus, and even heart issues. Some rare neurologic situations are posterior fossa abnormalities, dandy-Walker malformation, and blake's pouch. There is an increased frequency of malformations and medical complications, including abdominal wall defects and visceromegaly involving liver, spleen, pancreas, kidneys, or adrenals.

Within the couple of hours of my niece Janelle being born, doctors were concerned how little she was and her slow mobility. Unaware of her condition in Brownsville, she was sent to Driscoll Hospital in Corpus Christie within a couple of weeks. While being in the care at the hospital, medical doctors diagnosed Janelle with Prader-Willi Syndrome. As you can imagine, so many questions and thoughts went through her parent’s minds. To start, what is Prader-Willi Syndrome (PWS)? According to Genetic Home Reference, PWS is a complex genetic condition that affects many parts of the body, such as muscle tone, insatiable appetite, intellectual impairment, and learning disabilities. Which Janelle experiences these abnormalities and we have to take precautionary actions on a daily basis. It is a rare disorder present at birth and we can do nothing to prevent this and

These tests include DNA-based methylation testing, fluorescence in situ hybridization, and genetic testing. The DNA-based methylation tests a specific region on chromosome 15 to find if there is any abnormal parent-specific imprinting. This means that the test will be able to determine if the chromosome is either inherited from the mother only or properly inherited from both parents (GHR 2014). For example, the deletion of the 5-6 Mb region of chromosome 15 would be what researchers looked for with the DNA-based methylation. However, the other tests are just as effective as the DNA-based methylation, because they are trying to get the same end result (Cassidy et al. 2012). The DNA-based methylation test would be able to show us that the 5-6 Mb region on chromosome 15 in deleted. Then from there people can look at what happens in the 5-6 Mb regions to determine that it causes several genes that help with providing instruction on making molecules to be lost. An example would be the nucleolar RNAs. This gene aids in regulating other RNA molecules, which help with producing proteins and other activities in cells (GHR 2014). Part of the segment that is lost on the paternal chromosome 15 also contains the OCA2 gene, which aids in determining the pigmentation of eyes, hair, and skin. While Prader-Willi syndrome is characterized by only having maternal chromosome 15, Angelman syndrome is characterized by only having paternal chromosome

The deletion of chromosome 22 plays a crucial role in the development of a person. Since the major functions of the body are affected, daily life of someone diagnosed with DiGeorge syndrome has an underdeveloped reading and spelling comprehension. By the ause of low-average spelling and reading cognition, children with DGS have different learning environments in school. Children with this syndrome have to be put in special classes, because they learn on different, slower levels. On the severity of the disorder, some children have special courses and classes in school so they can reach their full potential. Daily life of someone diagnosed with DGS can vary on the criticalness of the disorder (Simon).

In conclusion, genetic disorders mutate the DNA and in some cases, delete portions of it. Williams Syndrome is a genetic disorder that affects the genetic material on the seventh chromosome. The locus of 7q11.23 has over 25 genes deleted, which is why Williams Syndrome has so many implications and symptoms. Distinct facial features and facial structure characterize Williams Syndrome. It can also be marked by severe cardiovascular difficulties and other issues that make life quite difficult for the person suffering from this disorder. Williams Syndrome also affects the mental capacity and logical thinking of the brain. This implies that daily tasks and schoolwork can be greatly affected and require special care. Williams Syndrome is also considered