Single Gene Disorder

Because there are different types of Waardenburg Syndrome, there are different types of inheritance patterns. Types I and III have an autosomal dominant inheritance pattern while types II and IV have an autosomal recessive inheritance pattern (Calendar 2013). The most common type of inheritance is the autosomal dominant inheritance (Type two 2013). An autosomal dominant inheritance pattern means that the mutated gene (EDNRB, EDN3, MITF, SNAI2, PAX3 and SOX10) is in each cell to cause Waardenburg Syndrome (Genetics 2013). In other words, only one parent has to have the copy of the altered gene in order for someone to have the syndrome. An autosomal recessive inheritance pattern means that the mutated gene has to come from both parents in order for a person to have Waardenburg Syndrome (Calendar 2013). Even though both parents carry the mutated genes, they don’t usually show any signs or symptoms of Waardenburg Syndrome.

Sickle cell: One of the first inherited diseases to be unraveled at the level of DNA was sickle-cell anemia which is defined as abnormal, crescent-shaped red blood cells that results from a single change in the amino acid sequence of the cell's hemoglobin, which causes the cell to contort, especially under low-oxygen conditions. (medical dictionary, 2017) Also, called drepanocyte, meniscocyte. Also, this blood disorder mostly affects Africans and natives of the Mediterranean region are those who are affected by malaria. A single mutation in the gene for the blood protein hemoglobin can affect its ability to transport oxygen around the body. People who inherit two copies of the same mutation, one from each parent, have severe symptoms.

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.

The P1 cross was between four wmf females and nine wild-type males. The F1 progeny consisted of 12 wild-type females, and four triple-mutant males. The P2 cross resulted in 13 females, and 3 males, all with the wild-type phenotype (Table 1). The two parental crosses identify that the mutations are X-link recessive. The triple-mutant females of the P1 cross produce mutant male offspring, but wild-type females. The F1 females would be heterozygous for the mutations, but don’t express the mutations because they still have a wild-type X chromosome. However, the F1 males only have one X chromosome that comes from a mutant mother. The offspring for P1 were crossed again to make and F1 cross. The F1 cross would be X+/Y and X+/X. The F1 cross resulted in 100 F2 progenies over the course of 7 days.

There are many known genetic diseases in the world. There are different types such as chromosomal and monogenic. Chromosomal disorders are when someone has too many or not as many chromosome as they are suppose to have (46 total chromosomes). Chromosomal disorders can also manifest when there are structural abnormalities. Monogenic disorders are an inherited medical condition caused by a DNA abnormalities. These diseases occur all throughout the world today. Depending on what region of the world you are in depends on what the most common ones are. Cystic Fibrosis has become the most common lethal genetic disease in the United States as of 1999. Although there are treatments available, there is not a known cure, and the effects remain burdensome

gene, which means that the mutated gene must be inherited from both parents. It is a very

Cystic Fibrosis is an autosomal recessive inherited disease (30. Meaning that there needs to be a presence of two abnormal or mutated genes to cause Cystic Fibrosis, one from mother and one from the father (3). Thus, the normal gene is dominant over the recessive mutated gene (2). These genes are only inherited from parents who are carriers (Gg) or have the disease (gg) (3). Carriers of Cystic Fibrosis have the presence of the mutated gene (g) but do not have Cystic Fibrosis (3). If two people who are carriers of Cystic Fibrosis (Gg) reproduce, their offspring have a 25% chance of getting Cystic Fibrosis (1).

When people think about a mutation or a genetic disorder, they often tend to think about fictional like characters such as a half beast half man scenario. However, genetic disorders and mutations are simply just mistakes in the genetic code. These mistakes can be so minor that it has no effect on you whatsoever, or they can be a major problem. Myotonic dystrophy type 1 is one of those genetic mistakes that has a huge impact on the way you live your life. Myotonic dystrophy type 1 is a type of multisystem disorder that cannot be caught, but is genetically inherited. Myotonic dystrophy type 1 has to do with a special gene and chromosomal problem, with very severe, rare symptoms, and it has a major impact on life.

There are two types of diseases, infectious and genetic. Unlike infectious diseases that are caused by organisms such as bacteria, genetic disorders are caused by mutations in an organism’s DNA. Cystic Fibrosis is a genetic disorder that is recessive autosomal and causes the creation of thick and sticky mucus. Because the disorder is recessive there must be two recessive alleles present for the trait to be expressed. Whereas in dominant disorders only one dominant allele needs to be present to express a disorder. For there to be two recessive alleles, both of the parents must be homozygous recessive or heterozygous for the offspring to express the recessive trait. If the offspring is heterozygous they will become carriers of the disorder and

An example of a dominant genetic disorder is Huntington’s disease or HD. Huntington’s disease affects the brain and causes the nerve cells in the brain to breakdown. Once the nerve cells are affected, a person’s physical and mental state will start to deteriorate. Huntington’s disease is incurable and affects people from 30 to 50 years old. Once a person has had HD for more than 10 years, the

Recurrent epistaxis is one of the diagnostic criteria for Hereditary Hemorrhagic Telangiectasia (HHT). HHT is an autosomal-dominant disorder that is also depicted by skin and mucosal telangiectasias. Feared complications of HHT include rupture of pulmonary or cerebral arteriovenous malformations (AVM). The etiology of HHT is most often due to genetic mutations that impair normal angiogenesis. We report a case of suspected HHT in a 49-year-old female, with a first-degree relative with HHT, and a history of recurrent epistaxis status post coiling of left and right internal maxillary arteries. Of special note, her initial hemoglobin level was 1.7, but she was alert and walking at triage. Her presentation was consistent with multiple prior admissions in the past three years. Patients with suspected hereditary telangiectasia should receive a comprehensive work up, including serum studies, imaging, and possibly genetic testing. Treatment should focus on both acute management of the bleed and prevention of future complications.

Genetic disorders can also be hereditary and can be passed down from generation to generation. There are two types of genetic disorders, single gene and multigene. Single gene focuses specifically on one gene while multigene disorders affect multiple genes and there are more of them. Moreover, single gene disorders are far more numerous than generally assumed, and as a group, they are certainly not rare (Ropers, 2010). As stated by Hans-Hilger Roper, single gene disorders are more rare than many might think. The chances of being born with a certain genetic disorder could possibly range from 1 in 500 to 1 in 10 million. While these numbers for a single genetic disorder might not be significantly high, the tens of thousands diseases bundled together adds

Lysosomal storage diseases form due to the modification of lysosomal enzymes. The diseases can be metabolically inherited through gene mutation. In “Lysosomal Storage Disease”, Michael Kruer (2) claims that,

Genes decide almost everything about our bodies, our eye colors, hair type, hair color, skin color, nose size, even the shape of our ear lobes. Our genes come from our parents, half from your mother and the other half from your father, and are found on our chromosomes which are inside cells. Most of the time everything goes good and the DNA divides successfully but sometimes a genetic disorders occurs, this happens when there is an abnormal biological development. This could be caused when the DNA divides and there is an error or by irregular single genes. Usually, these chromosomal abnormalities are just accidents that happen, meaning that they are a one-time incident and won’t affect any future pregnancies. But, the irregular single gene

When discussing the topic of genetics, it is typically viewed from the perspective of Mendelian inheritance in which genes are transmitted from parent to offspring solely through the use of genetic alleles, which are the alternative form of genes that have varying DNA sequences and chromosomes that affect the phenotype, visual gene trait (Toth. 2015). If and how a genetic trait is expressed is whether the alleles for that trait are dominant or recessive. Dominant alleles are genes that have a higher probability of being expressed in the offspring than a recessive allele. In the case of dominate alleles; there are two possible combinations that its gene can still be expressed with, homozygous (which contains two dominant alleles) and heterozygous (which contains a dominant and recessive allele). On the other hand, recessive alleles can only be expressive if it is homozygous (which contains two recessive alleles) (Reece et al. 2013).