2.1.1 Chronicles of a Genetic Chronicles.docx - What are...

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•What are Genetic Disorders?•Both environmental and genetic factors play a role in the development of disease.•A genetic disorder is a disease caused by abnormalities in an individual’s genetic material.–In this course, we will consider four different types of genetic disorders:•Single-gene•Multifactorial•Chromosomal•Mitochondrial•Single Gene Disorders•Single gene disorders are caused by changes or mutations that occur in the DNA sequence ofone gene.•Remember that a gene, a segment of DNA, contains instructions for the production of a protein(or the transcript for the protein)•Diseases and disorders result when a gene is mutated resulting in a protein product that can nolonger carry out its normal job.•Single Gene Disorders•Single gene disorders are inherited in recognizable patterns:–Autosomal dominant( need one allele)–Autosomal recessive(need 2)–Sex linked•Genetic testing looks at genotype to determine if someone has a genetic disorder, will developone, or is a carrier.•Multifactorial Disorders•Multifactorial disorders are caused by a combination of environmental factors and mutations inmultiple genes.–Development of heart disease is associated with multiple genes, as well as lifestyle andenvironmental factors.–Different genes that influence breast cancer development have been found on chromosomes 6,11, 13, 14, 15, 17 & 22.•Many of the most common chronic illnesses are multifactorial.•Chromosomal Disorders•Humans have 46 chromosomes in their body cells.–44 autosomes–2 sex chromosomes
•Because chromosomes carry genetic information, problems arise when there are missing orextra copies of genes, or breaks, deletions or rejoining of chromosomes.•Karyotypes, pictures of the paired chromosomes of an individual, are important in diagnosingchromosomal disorders.•Mitochondrial Disorders•Mitochondria, the organelles in your cells that convert energy, also contain DNA.•A mitochondrial disorder, a relatively rare type of genetic disorder is caused by mutations in nonchromosomal DNA of mitochondria.•Mitochondrial DNA is unique in that it is passed solely from mother to child•Types of Genetic Testing and Screening•Carrier Screening•Carrier screening determines whether an individual carries a copy of an altered gene for aparticular recessive disease even though they do not show the trait phenotypically.•Carrier screening is often used if a particular disease is common in a couple’s ethnic backgroundor if there is a family history of the disease.•Examples of carrier tests include those for Tay-Sachs disease or sickle cell disease.•Preimplantation Genetic Diagnosis (PGD)•PGD is used followingin vitrofertilization to diagnose a genetic disease or condition before theembryo is implanted in the uterus.•A single cell is removed from an embryo and examined for chromosome abnormalities orgenetic changes.•Parents and doctors can then choose which embryos to implant.•Secrets of the Sequence – Chosen Child video. Type in

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Term
Spring
Professor
Mrs. M
Tags
Genetics, Schizophrenia, Genetic disorder, labs conclusionquestions, single gene disorders

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