Genetic and Developmental Disorders PDF

Genetic and Developmental Disorders Chapter 6 Copyright © 2023 Wolters Kluwer · All Rights Reserved Module Objectives Upon completion of this module, the student will be able to: 1. Define terms associated with genetics and genomics; genotype and phenotype. 2. Describe the basic str...

Genetic and Developmental Disorders Chapter 6 Copyright © 2023 Wolters Kluwer · All Rights Reserved Module Objectives Upon completion of this module, the student will be able to: 1. Define terms associated with genetics and genomics; genotype and phenotype. 2. Describe the basic structure of DNA and genes. 3. Identify the implications al alteration in the structure and function of genes and chromosomes. 4. Utilize Punnett Square to determine inheritance patterns. 5. Discuss the influence of gene-environment interactions on developmental disorders and future development of genes. 6. Apply concepts of alterations in genetics and development to select clinical exemplars. Copyright © 2023 Wolters Kluwer · All Rights Reserved The Roadmap of a Health Journey Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Genetic Composition Overview Copyright © 2023 Wolters Kluwer · All Rights Reserved Genetic System Components Nucleotides DNA Genes Chromosomes Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Genetic System Components Nucleotide Paring Adenine and Thymine (A)-(T) Guanine and Cytosine (G)-(C) * Thymine  Uracil in RNA Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Genetic Code Production Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Chromosomal Replication Double-stranded DNA in cell Mitosis  2 identical cells nucleus with 23 pairs of 22 pairs of autosomes chromosomes 1 pair of sex Meiosis  4 cells with 23 chromosomes single chromosomes Contain genetic information of an individual Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Genetic Inheritance Why should nurses care? Copyright © 2023 Wolters Kluwer · All Rights Reserved Genetic Alterations in Human Disease Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved.  Single Gene Trait Inheritance Mendelian Autosomal Autosomal Sex- pattern of predictable trait Dominant Recessive Linked transmission Allele expression mutation involving two recessive Mutation located on the sex Dominant alleles results in chromosomes, expression of the most often to X Recessive mutation involving trait one dominant allele results in expression of the trait mutation involving one recessive Males are more allele results in likely to be affected carrier status for the trait Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Genetic Mutations Deletion Duplication Inversion Insertion Translocation Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Gene Inheritance Patterns 13 Mendelian Inheritance Autosomal E.g., Sickle Cell (r) E.g., Marfan Syndrome (D) Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Gene Inheritance Patterns 14 Mendelian Inheritance Sex-Linked E.g., Hemophilia Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Inheritance of Polygenic Disorders Multiple alleles at different chromosome locations affect phenotype Complex interaction of multiple factors Environmental influences (height) Less predictable pattern Chromosomal alterations: Monosomy (Turner syndrome) Trisomy (Down syndrome) Copyright © 2023 Wolters Kluwer · All Rights Reserved Application to Clinical Exemplars Huntington Disease Sickle Cell Disease Down Syndrome Fragile X Syndrome Copyright © 2023 Wolters Kluwer · All Rights Reserved What should I know about each disorder? Etiology What is the primary cause? Inheritanc How is the disorder passed on from parents? e Morphologi What structural changes are occurring in the cells c Changes and tissues that are characteristic of the disorder? Functional How are these changes manifested clinically? What Consequence are the characteristic assessment findings? s Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Autosomal Dominant Genetic Disorder Huntington Disease Copyright © 2023 Wolters Kluwer · All Rights Reserved Huntington Disease Etiology & Risk Factors Progressive degenerative neurologic disorder with an autosomal Pathophysiology dominant inheritance pattern Defect in Huntington 50% chance of gene on chromosome 4 passing on to children Too many CAG repeats Mid-life onset, equally generates the abnormal, affects men and toxic Huntington protein women Degeneration of the basal ganglia and cortical regions of the brain Movement, emotional, and cognitive impairment Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Huntington Disease: Pathophysiology Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Huntington Disease: Assessment Findings Click to edit 1. Involuntary Master text movements styles Dyskinesia Click to edit Chorea Master 2. Cognitive text styles impairment Click to edit 3. Emotional Master text disturbance styles Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Huntington Disease: Assessment Findings Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Autosomal Recessive Genetic Disorder Sickle Cell Disease Copyright © 2023 Wolters Kluwer · All Rights Reserved Sickle Cell Disease Etiology & Risk Factors Single gene mutation with autosomal recessive inheritance Homozygous: disease Pathophysiology phenotype Heterozygous: carrier Point mutation More common with leading to altered ancestry from sub- structure of the Saharan Africa, South beta chain of America, the Caribbean, hemoglobin in red Central America, blood cells Sickled shape, known Mediterranean countries as hemoglobin S (HbS) Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Sickle Cell Disease: Assessment Findings Click to edit Master text styles 1. Anemia Click to edit 2. Pain Master 3. Organ damage text styles 4. Jaundice Click to edit Master text styles Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Alteration in Autosome Chromosome Number Down Syndrome Copyright © 2023 Wolters Kluwer · All Rights Reserved Down Syndrome Etiology & Risk Factors Alteration in autosome number No known risk factors, Pathophysiology but incidence increases with maternal age Trisomy (3 copies) of Can be screened for chromosome 21 during pregnancy Random error in cell division = nondisjunction or inherited translocation Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Down Syndrome: Pathophysiology Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Down Syndrome: Assessment Findings 1. Mental delay Click to edit 2. Facial features Master text styles Upward slanting Click to edit eyes Small, low-set ears Master Small mouth, protruding tongue text styles Short neck Click to edit 3. Short stature Master text styles 4. Decreased muscle tone Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Sex-Linked Genetic Disorder Fragile X Syndrome Copyright © 2023 Wolters Kluwer · All Rights Reserved Fragile X Syndrome Etiology & Risk Factors Pathophysiology Sex-linked genetic Unusual mutation in the disorder fragile X mental retardation More prevalent among 1 (FMR1) gene males Impaired ability to produce fragile X mental retardation protein (FMRP), needed for brain development Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Fragile X Sydnrome: Assessment Findings 1. Cognitive impairment Click to edit Master text 2. Behavioral styles difficulties Click 3. Facialto edit features: Master Protruding lower jaw text Largestyles head Broad forehead Click to edit Master text 4. Hyperflexible styles joints Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Fragile X Syndrome Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved. Summary Things I should know: Now take the Genetic Disorder quiz in Canvas. Basic understanding of protein synthesis Quiz access and DNA production code is: Genetic inheritance using a Punnett 1234 Square Cause, type of inheritance, and Please reach out to the course faculty with any questions! assessment findings: Huntington Disease Sickle Cell Disease Down Syndrome Fragile X Syndrome Copyright © 2023 Wolters Kluwer · All Rights Reserved © UAB. All Rights Reserved.