Phenylketonuria And Hereditary Diseases

In some cases there are very mild symptoms or no symptoms at all . Parents and children can get disease without realizing it before.

This syndrome is tested at birth with fluorescent in situ hybridization or FISH. With blood samples, they test the blood for the deletion of chromosome 7. FISH checks if many as of 22-26 genes are deleted. Because there is no cure for this syndrome, you will most likely have physical therapy and early education to help early development symptoms like speech delays and heart problems. This syndrome is not caused by environmental factors, it is completely genetic and NOT the parents fault.

will have a 1 in 4 chance of having t of h this disease, 2 in 4 chance of b b being a carrier, and 1 in 4 c

▪ Every age group is affected mutation (an only mutation has all to say concerning whether one will get the disease).

The mother, who is a carrier, inherits an X-Linked or sex-linked faulty gene. The result is producing an affected son and or a daughter being a carrier. The second way is an affected male producing children, particularly daughters. All daughters born to fathers with x-linked muscular dystrophy will be carriers; on the contrary their sons will be unaffected. Scientists link this to a genetic mutation in the gene, appearing most often for the first time in a family.

b. How is it caused on a genetic level? Be specific about the chromosome #, genetic mutation, dominant or recessive, and chance of inheriting the disorder.

Females are carriers in their X-Chromosome and they have the chance of passing the disease on to their children, 50-50 to a girl and 50-50 to a boy. If the girl does receive the gene she becomes a carrier. If the boy gets the gene then he has the disease. Males do not pass on the gene to their children because they pass on the Y-chromosome and the disease is X specific. Some female carriers have indicators of being a carrier by having symptoms of cardiomyopathy, shortness of breath during exercise, and muscle weakness in the back, arms, and legs. There have been very rare instances where a girl has not received a

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.

This happens when an affected parent has one recessive gene and one dominant gene whereas the other has two recessive genes, which allows two children to get two recessive genes meaning they will not be affected. Whereas the other two have one dominant gene meaning they will be affected by the disease.

Since the gene is recessive, a child will only present the symptoms of SLOS if both parents pass on a defective copy of the DHCR7 gene. Although it is rare, it happened to Audrey. Both of her parents, Amber and Brad Bowers, were unaware that they were carriers of the gene for SLOS. A carrier is a person who has one healthy copy and one mutated copy of a specific gene, and therefore does not present or experience any symptoms of the disorder. Since both Amber and Brad are carriers of the SLOS disease, each child they have will face a 25% chance of having SLOS. Brad and Amber currently have 3 children: Audrey (5yo) who is affected by SLOS, Liam (3yo) who is unaffected and Ben (1yo) who is also unaffected. Sadly, Brad and Amber lost their youngest son, Gabriel, after he battled with SLOS for 6 months. Studies indicate that SLOS affects approximately 1 in 20,000 to 60,000 newborns each year and this condition is most common in whites of European ancestry

If there is any alterations in these genes you are more likely to inherit this disease in earlier stages.

If the disease is of the homozygous variety in a person it occurs in 1 in every 10,000 people. If the disease is heterozygous then in is found between 1 in every 5,000 people and 1 in every 15,000 people. It is more common in Venezuela then anywhere else, although it is discovered in about 240 people per year in the United States. A DNA marker G8 (D4S10) is closely linked to HD and has been identified as being on the # 4 chromosome and can detect Heterozygotes. (Encarta Encyclopedia) The connection between G8 and HD has not been clinically used because it’s a very serious disease. Theoretically a homozygote can be detected parentally. If a female has a child and she is tested positive for HD and has no history of it, then the father as well as the child a bound to end up with the disease. (Textbook

Tay-Sachs disease is caused by a defective gene on chromosome 15. When both parents carry the

PKU is passed on in a “autosomal recessive” gene. This means that a person may have one of the genes for the disease but if they have the other dominant gene they will not be affected by the disease. In the diagram ‘P’ is the dominant gene and ‘p’ is the recessive gene. People who have one recessive gene and one dominant gene ‘Pp’ are called silent carriers. The person with ‘PP’ does not have any of the PKU gene. The person with ‘pp’ has PKU. Each time two carriers reproduce the chances the baby of having PKU is 25%. The chances of them being a silent carrier is 50%. One in every about fifty people in the general population are carriers. And the chances of that carrier’s mate is a carrier is about one in 2500. PKU occurs in about one of out every 10,00 babies born in the United States. Incidents of this disease occur equally in male and female babies.

If Lisa conceived this child naturally, it would have a 25% chance of developing the condition also.