Neurofibromatosis Type one (NF1) is the most common genetic disease in the world, and it affects one in every 3,000 to 4,000 births worldwide (Children’s Tumor Foundation, 2014). Neurofibromatosis comes in three different types: Schwannomatosis is the most severe, then Neurofibromatosis Type two (NF2), and finally the least severe, Neurofibromatosis Type one. Depending on the severity of NF1 a person could live a perfectly normal life; however, life-debilitating complications are still possible and treatments can be time consuming.
NF1 is also known as Recklinghausen Neurofibromatosis or Peripheral Nerve Neurofibromatosis (Children’s Tumor Foundation, 2014). The nervous system consists in two parts: the central nervous system(CNS) and peripheral nervous system(PNS). The CNS consists of the brain and spinal cord, while the PNS consists of all the cranial and spinal nerves in the body (Shire, Butler, Lewis, 2013, pg.361). A person who has NF lacks a protein that prevents tumors from growing anywhere in the nervous system.
What causes this lack of protein? NF1 falls on the seventeenth chromosome and its exact location on the chromosome is 17q11.2 or between the 31,045,487 to 31,377,676 gene (National Library of Medicine, n.d). The NF1 gene is supposed code for a protein called neurofibromin. Neurofibromin is a specialized protein that produces oligodentritcyte (National Library of Medicine, n.d.). Oligiodentritcyte forms the myelin sheath, which is also known as the Schwann cell, which is found on the axon of a neuron in the PNS (Shire, Butler, Lewis, 2013, pg.361). Neurofibromin acts like a tumor suppressor protein, so a person with NF1 is more prone to getting tumors, so without neurofibromin the mitosis cycle conti...
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...ere are three types of Neurofibromatosis, which are Schwannomatosis, which is the most severe, NF2, and finally the NF1, which is the most common. NF1 occurs one in every 3,000-4,000 births worldwide. Unfortunately, there still is no cure even though NF1 is the most common genetic disease in the world. Each person with NF1 has a unique case that can vary in the severity of their complications, one person my not be affected by it that much, while another is greatly impacted by it, and potential could need a lot of time consuming treatments.
References
Children’s Tumor Foundation (2014). http://www.ctf.org/Learn-About-NF/Learn-About-NF.html
National Library of Medicine. (n.d.). Retrieved from http://ghr.nlm.nih.gov/condition/neurofibromatosis-type-1
Shier. D, Butler. J, & Lewis. R. (2013). Holt’s Human Anatomy & Physiology. Thirteenth edition.
Marieb, E. N., & Hoehn, K. (2013). Human anatomy & physiology (9th ed.). Boston, MA: Pearson.
In Jan Tecklin’s book, Pediatric Physical Therapy, he states that “spina bifida is the second most common birth defect after Down syndrome” (163). Spina bifida includes any birth defect where the spinal canal is not completely closed. It is considered to be a neural tube defect or an NTD. The
Spina Bifida is the most common permanently disabling birth defect in the United States. It is a birth defect in which a developing baby's spinal cord fails to develop properly. The term Spina bifida comes from Latin and means "split" or "open" spine. This disorder occurs when the fetus is growing in the womb and its spine doesn’t form correctly. Some of the vertebrae don’t close to make their normal ring shapes around the spinal cord. This defect happens at the end of the first month of pregnancy, when a baby's spine and spinal cord are developing. Causes of Spina Bifida Causes that cause this disorder are low levels of the vitamin folic acid during pregnancy. Not having enough folic acid in the diet before and during early pregnancy can increase a woman's risk of Spina bifida and possibility of other neural tube defects. A high fever during pregnancy may increase a woman's chance of having a baby with Spina bifida. Some evidence suggests that genes may be a cause of Spina Bifida, but most babies born with Spina bifida have no family history of the condition. Also, women with epilepsy
Marfan syndrome (MFS) is known as an autosomal dominant hereditary disorder of connective tissue. Connective tissue helps support all parts of the body. It also helps control how the body grows and develops. Principal manifestations involve the ocular, skeletal, and cardiovascular systems. MFS is caused by mutations in the glycoprotein gene fibrillin-1 (FBN1) which is located on chromosome 15(Marcheix, 2008). There are many mutations that can cause Marfan Syndrome, but most common are missense in that they are single-nucleotide changes that result in the substitution of a single letter that leads to a single amino acid change in the protein. The change in the amino acid alters the shape of the fibrillin proteins. The irregularly-shaped protein then assembles into irregularly shaped microfibrils. Fibrillin is a major element of microfibrils, which store a protein called transforming growth factor beta (TGF-β), a critical growth factor. TGF-β helps control the proliferation of cells, cell differentiation, cell movement, and apoptosis. Microfibrils help regulate the availability of TGF-β, which is deactivated when stored in microfibrils and activated when released. The increase in TGF-β and abnormalities involving microfibrils causes problems in connective tissues throughout the body such as malformations and disfigurements of the ligaments, spinal dura, lens zonules, and lung airways(Marcheix, 2008). The heart is also greatly negatively impacted through a weakening of the aortic wall, progressive aortic dilatation or aortic disjointing can occur because of strain caused by left ventricular contractions.
Survival Motor Neurons are a protein that is produced by the survival motor neuron gene 1. The SMN protein is found all over the body, especially containing high levels in the spinal cord. This protein is important for maintaining specialized nerve cells called motor neurons that are located in the spinal cord and brainstem. When a person have An abnormal or missing SMN1 it causes serious problems due to the fact it isn’t receiving the proper communication from these cells resulting in nerve cells shrinking and over time dying.
Canavan Disease is a fatal neurological disease where there is significant damage to the nerve cells in the brain. There is a defect in the myelin sheath that causes many problems for the nervous system. The major problem is caused when the enzyme aspartoacyle is not present. This missing enzyme causes a chemical imbalance that causes this defect in the myelin sheath. The myelin in the brain destructs which makes it a spongy tissue. This causes overall muscle weakening and slower movements, leading to severe mental retardation. A recent study has shown that the cells in the brain that are responsible for making myelin sheaths (oligodendrocytes), cannot complete the task. When babies are born they may not show any signs at all until the first few months. This disease is only inherited and categorized under a group of diseases called leukodystrophies. Leukodystrophies gets its name because it means there is a degeneration of myelin, which is a fatty cushioning that shields nerve fibers. This makes the nerve signals very difficult to transmit. People with Canavan Disease life span can range from a couple days, months, or maybe even until their twenties (Genetics Home Reference, n.d.); (Canavan Foundation, n.d.).
A. NF is caused by a mutation in the NF1 gene, which creates the protein neurofibromin.
Marfan syndrome is an inherited disorder that affects the connective tissue of the body (“What is Marfan Syndrome?” n.d.). The connective tissue plays a vital role in supported the tendons, heart valves, cartilage, blood vessels, and more parts of the body (“Connective Tissue,” n.d.). “What is Marfan Syndrome?” (n.d.) explains that the condition has no cure, and those who have it lack strength in their connective tissue, affecting their bone, eyes, skin, nervous system, and lungs. Furthermore, Marfan syndrome is common, and it is imperative to understand how the body is affected by it, the symptoms, and the treatment of this condition.
During fetal growth, the neural tube can develop any number of abnormalities. These “malformations occur because the tube fails to close properly, because parts of it are missing, or because part of the tube is blocked” (neural tube defect, 2014). Ramírez-Altamirano et al. (2012) have stated that “the most common types of neural tube defect are anencephaly, spina bifida, and encephalocele, all of which represent 95% of the cases.” Anencephaly is the most severe form of neural tube defect. In this condition the cephalic portion of the neural tube fails to close properly, resulting in very little cerebral tissue forming. Infants born with this defect are usually stillborn or live for a very short amount of time. Spina bifida consists of “a group of malformations of the spine in which the posterior portion of the bony canal containing the spinal cord is completely or partially absent” (Frazier & Drzymkowski, 2013, p. 63). This condition typically affects the lumbar portion of the neural tube, a...
The disease is found in a mutation on the HEXA gene. The HEXA gene makes beta-Hexosaminidase A, an enzyme that is necessary for proper spinal cord and brain development. This works to break down GM2 ganglioside, a fatty substance. When a mutation occurs here, the GM2 ganglioside can’t be broken down, accumulating to harmful levels in neurons of the brain and spinal cord, which results in the damaging symptoms of the disease.
(Marieb, 2016). Myelin is the protective coat surrounding and insulating the nerve fibers of CNS. Myelin is fatty tissue substance that if attacked by immune cells causing a short-circuits in the current so that the successive gaps are excited more and more slowly, and eventually impulse conduction ceases which resulted in various forms of symptoms (Marieb, 2016). The degradation could either be “by inflammation, stroke, immune disorder, metabolic disorders, or nutritional deficiencies” (Slomski, 2005). The target that immune cells are sensitized to attack remains
Marieb, E.N., Hoehn, K. 2013. Human Anatomy and Physiology. 9th edition. Pearson Education Inc. ISPN-13: 978-0-321-74326-8.
Therefore, NFS is inherited as an “autosomal recessive trait” which means that there are 2 copies of the mutation, which are required to produce a positive offspring.
Marieb, E. N., (2006). Essentials of human anatomy and physiology. San Francisco, CA: Benjamin Cummings.
With motor neurone disease it attacks the nerves, in the brain and spinal cord. This means messages gradually stop reaching muscles, which leads to weakness and wasting. In the case study the