Nursing 3366 Pathologic Processes: Implications for NursingGenetic Influence in DiseaseObjectives /outcomesDESCRIBE/DISCUSS/IDENTIFY:- various multifactorial genetic disorders - pathophysiology of basic chromosomal problems such as Down’s- single-gene alterations resulting in protein synthesis defects and their relationship to disease processes & symptoms, such as sickle cell anemia, polycystic kidney disease, hemophilia- some therapeutic uses of recombinant DNA.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~NOTE: Usually you are expected to come fully prepared with A&P knowledge (by reviewing Prep ahead of time) so that we can dive right into the patho. For this first day, however, we will quickly go over a couple of key things that you will need to understand the main lecture. (Hopefully you will remember some of this from A&P classes).1. Gene definition and function a. Definition of a gene--a segment of a DNA molecule that is composed of an ordered sequence of nucleotide bases (adenine, guanine, cytosine, thymine)b. Main functions of genes: coding for synthesis of proteins that influence all aspects of body traits and function.1) Examples of these include “permanent” proteins such as eye pigment, hair color, and blood type in a developing fetus, as wellas more subtle inherited traits like outgoing personality or susceptibility to certain diseases. 2) There are also “day-to-day” functional proteins such as hormones, antigens, antibodies, enzymes, etc. c. When there is a mutation of a gene, the protein it is responsible for often malfunctions. 1) You can have a pretty good idea of what type of disorder & S&S occur when you understand this pathologic process.2) Ex—if the gene that codes for lactase becomes mutated, what might happen? _____________________________________________2. Packaging of genes: chromosomes a. The DNA helix containing genes goes through many shapes during the celllife but at one point takes the shape that we are most familiar with– the rod-shaped body in the nucleus of cells called a chromosome. 1) To summarize: a sequence of nucleotide bases forms a gene; genes make up a DNA molecule, and that DNA molecule forms into aspecialized shape called a chromosome 2) A chromosome can be thought of (very simplistically) as a string of multi- purpose beads, with the beads being genes.b. A person receives 23 chromosomes from each parent, so you end up with 23 pairs, or a total of 46. 1) 22 pairs are autosomal– ie, NOT sex chromosomes– and each pair isclosely alike. 2) The other pair is the sex chromosomes– XX or XY.Pay attention to the objectives in all the lecture notes—much of the tests’ content is geared towards them & they give you areasto focus on.13) For purposes of study they can be arranged in a karyotype (apicture) ex— chromosome #1 from mom is matched up with chromosome #1 from dad.c. Autosomal chromosome pairs (#1-22). 1) For these pairs, each has genes that closely match “partners” on the other chromosome. 2) Partner genes have the same location (“locus”) on each respective chromosome, code for the same trait, and are called “a pair of alleles.”3) A pair of alleles are almost exactly alike except that one can be dominant & one can be recessive (or they can both be dominant or both be recessive).4) We notate recessive genes with a lower-case letter & a dominant gene as an upper-case letter.a) The combinations are called genotypes & represent what was inherited from mom & dad.b) Examples of various combinations (randomly using the letter “g”), canbe GG (homozygous dominant); gg (homozygous recessive); Gg (heterozygous).d. There is one pair of sex chromosomes (#23) which work very differently. There is info on them & on sex-linked disorders later in these notes, but you won’t be tested on that info. e. If a geneticist is trying to figure out the percent chance of two people withcertain genotypes having a child with certain genetic characteristics, a Punnett square is often used. (Note: you must understand & be ableto do Punnett squares for the exam). ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Outline for Lecture :II. Genetic disordersA. Overview1. definition of genetic disorders2. categorizing genetic disorders3. mitochondrial DNA disorders4. multifactorial5. chromosomal6. single-geneB. Single-gene disorders1. overview/ categories: autosomal recessive, autosomal dominant, sex-linked2. autosomal recessivea. overviewb. example of autosomal recessive disorder--sickle cell anemia3. autosomal dominanta. overviewb. example of autosomal dominant disorder—polycystic kidney disease See page 6 of Blueprint 1 for more info on understanding genotypes &Punnett 24. sex-linkedC. Recombinant DNA– a form of genetic engineering~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~II. Genetic disordersA. Overview1. broad definition of “genetic disorders”-- a disease caused by abnormalities in an individual’s genetic material2. there are several ways of categorizing genetic disorders:a. inherited vs “spontaneous”1) example of inherited disorders—sickle cell disease is caused by an inherited, altered (AKA, “mutated”) gene (see below)2) example of spontaneous—high level of exposure to radiation causes a mutation in a gene becomes an “oncogene” which causes rapid, wild proliferation of cell growth skin cancer develops.b. other ways to categorize include using the following four groupings: disorders of mitochondrial DNA, multifactorial, chromosomal, single-gene.3. mitochondrial DNA disordersa. majority of DNA is found in nucleus of cells but small bits of DNA arealso found in mitochondriab. disorders of this DNA are very uncommon & won’t be discussed here4. multifactorial genetic disorders -- combination of environmental triggers and variations / mutations of genes, plus sometimes inherited tendencies;examples:a. various cancers such as lung cancer: begins by smoke & toxins irritating bronchial tissue one or more genes in cells of that tissue begin to be deranged—oncogenes created  code for wild, uncontrolled growth of cells.b. many common diseases such as hypertension (HTN), coronary artery disease (CAD) & diabetes mellitus (DM) are now known to be caused or highly influenced by a mix of environmental and inheritedcomponents.c. ________________________________ disorders:1) a teratogen is any influence