Maternal Nursing: Genetic Assessment & Counseling PDF

MATERNAL NURSING NURSING ROLE IN GENETIC ASSESSMENT & COUNSELING Toni Marie B. Punzalan, MAN, RN  LEARNING TARGETS: 1. Describe the nature of genetic inheritance, patterns of recessive and Mendelian inheritance, and common chromosomal aberrations causing physical or cogni...

MATERNAL NURSING NURSING ROLE IN GENETIC ASSESSMENT & COUNSELING Toni Marie B. Punzalan, MAN, RN  LEARNING TARGETS: 1. Describe the nature of genetic inheritance, patterns of recessive and Mendelian inheritance, and common chromosomal aberrations causing physical or cognitive disorders. 2. Identify clients who may benefit from genetic counseling. 3. List the roles and responsibilities of the nurse in genetic counseling. 4. Explain the processes involved in assessing for genetic disorders. GENE REPLACEMENT THERAPY: experimental technique that uses genes to TREAT or PREVENT diseases GENE EDITING - DNA is inserted, deleted, modified or replaced in the genome of a living organism GENETIC DISORDERS: “inherited” passed from one generation to the next disorder in the gene or chromosome structure may occur at conception (meiotic division) may lead to spontaneous miscarriage (50%) GENETICS: the study of the way such disorders occur CYTOGENETICS: study of the chromosomes by light microscopy and the method by which chromosomal aberrations are identified NATURE OF INHERITANCE: Genes basic unit of heredity determine both physical and cognitive characteristics composed of segments of DNA that forms chromosomes Alleles two like genes on autosomes NATURE OF INHERITANCE: Phenotype expression of the genes outward appearance Genotype actual gene composition Genome complete set of genes (50,000 to 100,000) collection of genetic information NATURE OF INHERITANCE: Chromosomes storage unit of genes DNA nucleic acid (deoxyribonucleic acid) contains the genetic instructions spicifies the biological development of all cellular forms of life MENDELLIAN INHERITANCE: Gregor Mendel principle of genetic inheritance when dominant gene is paired with nondominant (recessive), the dominant genes are always expressed HOMOZYGOUS HETEROZYGOUS 2 healthy genes 2 unhealthy genes MEDICAL GENETICS: patterns of inheritance (rare disorders) Common Types: Autosomal recessive Autosomal dominant X-linked recessive X-linked dominant AUTOSOMAL RECESSIVE 2 genes for the disease are present homozygous pattern AUTOSOMAL DOMINANT either a person has 2 unhealthy genes homozygous dominant X-LINKED DOMINANT INHERITANCE genes are located and transmitted only by the female chromosome (X) if dominant, only 1 is needed for the symptoms to be manifested X-LINKED RECESSIVE INHERITANCE mothers are carriers usually male children will have the disorder both genes are present on both X chromosomes MULTIFACTORIAL INHERITANCE “polygenic’ inheritance from multiple gene combination plus environmental factors i.e. heart diseases, DM, cleft palate, neural tube defects CHROMOSOMAL ABNORMALITIES cytogenic disorders abnormalities due to fault in the number/structure of chromosomes FLUROSCENT IN SITU HYBRIDIZATION (FISH) - karyotyping photographed and displayed chromosomes CHROMOSOMAL ABNORMALITIES 1. NON JUNCTION ABNORMALITIES division is uneven 24 and 22 chromosomes (sperm and ovum) CHROMOSOMAL ABNORMALITIES 2. DELETION ABNORMALITIES part of the chromosome breaks normal # +/- an extra portion CHROMOSOMAL ABNORMALITIES 3. TRANSLOCATION ABNORMALITIES gains additional chromosome through another route CHROMOSOMAL ABNORMALITIES 4. MOSAICISM happens early in tissue development different cells have different chromosome counts CHROMOSOMAL ABNORMALITIES 5. ISOCHROMOSOMES division via horizontal cut mismatched long and short arms can result PURPOSES: Provide concrete, accurate information: process of inheritance & inherited disorders  Allow people to make informed choices about future reproduction  Offer support to people who are affected by genetic disorders NURSING RESPONSIBILITIES: Explaining to a couple what procedures they can expect to undergo  Explaining how different genetic screening tests are done and when they are usually offered  Supporting a couple during their wait for test results  Assisting couples in values clarification, planning, and decision-making based on the results  *Do not impose your own values or opinions