I will pay for the following essay Medical genetics. The essay is to be 11 pages with three to five sources, with in-text citations and a reference page.4 different genes are responsible for OCA- TYR,

I will pay for the following essay Medical genetics. The essay is to be 11 pages with three to five sources, with in-text citations and a reference page.

4 different genes are responsible for OCA- TYR, OCA2, TYRP1 and SLC45A2.One of the most commonly found mutation is in gene TYR which causes type I OCA. TYR is better known as tyrosinase gene. A normal TYR gene codes for the enzyme Tyrosinase. Mammalian melanogenesis is regulated at more than 90 loci in the gene. Tyrosinase is expressed the melanocytes and is a type I melanosomal glycoprotein. They play a pivotal role in melanin production in the melanocytes. Tyrosinase is produced in the ribosome and is transported through the endoplasmic Reticulum and Golgi apparatus into the melanocytes. Soon after this transportation melanin biosynthesis is initiated. Melanin is the pigment responsible for coloration of hair, skin and parts of the eyes (iris and retina). The enzyme converts protein tyrosine into another compound known as L-hydroxy-phenylalanine (DOPA) which is again converted to form DOPAquinone (dihydroxy phenylalanine quinine). This conversion is a critical step in melanin production process. This conversion is followed by a series of chemical reactions till melanin pigment is formed which imparts the color. TYR is present on 11q14-q21 and contains about 5 exons. The 5 exons span more than 65kb on chromosome 11q.Genetic testing has determined that TYR gene mutations mostly occur in the coding region and not in the proximal promoter region of the gene. More than 100 mutations have been identified to occur in the gene. The nature of the mutation are deletion, polymorphism, nonsense, frame shift and splice-site mutations. Sometime mutation in the gene eliminates tyrosine activity altogether giving rise to OCA type IA while other mutations causes’ diminished TYR activity leading to slight coloration which is known as OCA type IB. Patients with OCA IA perfectly white hair, pale skin and lightly colored eyes and they do not tan. Patients with OCA IB have white hair, pale skin and eyes but the color of hair and eye may darken with age and the skin is slightly prone to tan. OCA Type II can be further categorized for milder forms of the disease. Symptoms of Oculocutaneous albinism include hypopigmentation of skin and hair, congenital nystagmus, reduction in pigment in the iris and iris translucency, vision acuity reduction, impairment of color vision, photophobia etc. Deficiency of pigment in the iris diminishes proper functioning and reflects light leading to refractive errors. Patients with this disorder are prone to skin cancer. Molecular sequence analysis of the TYR coding gene is done to facilitate implementation of management strategies because clinical manifestations of the different types of albinism overlap each other. However, owing to presence of a pseudogene of TYR which has similar exons similar to exons 4 and 5 of Tyr gene, analysis of mutation is hampered. There is no cure for this disorder. The diagnosis includes better management or the disorder and alleviation of further problems or complications. Managing the disorder includes protection against exposure to light by using covering clothes, hats, sunscreens and sun shades since even the slightest exposure to sun rays may cause skin burns. Other steps include usage of spectacles to correct eye problems and frequent testing for skin cancer.