Genetic Disorders And Genetic Mutations Essay

1599 Words Apr 3rd, 2015 null Page
According to Simon and Farndon (2008), genetic disorders are abnormalities in an individual 's gene or set of genes which could be due to mutations in the DNA. Also, there are thousands of genetic diseases that can occur as it is estimated that the average rate of genomic mutation is about 2x10-8 per nucleotide per genome (Nachman and Crowell, 2000). Furthermore, they can be grouped into three types named single gene disorders, chromosomal disorders and multifactorial conditions (Milewicz, 2007). Firstly, single gene disorders have mutations that affect specific genes. Moreover, they are classified as either autosomal or sex linked and can be dominant or recessive (ibid). Additionally, sex linked disorders can be X or Y linked depending on which chromosome is affected. Y-linked diseases only affect males while x-linked diseases are more predominant in males as females have an extra X chromosome to mask the effect of the affected one while males only have one e.g. haemophilia (Simon and Farndon, 2008). Secondly, Milewicz (2007) explains that chromosomal disorders occur when whole or portions of chromosomes are lacking, in excess or changed due to mutations in DNA sequence e.g. Down’s syndrome. Lastly, multifactorial disorders occur due to mutations in two or more genes e.g. cancer (Simon and Farndon, 2008). According to the family tree, the unknown disease is x-linked recessive as it only affects the males and is not present in every generation. The disease is also known to…

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