Genetic Disorders and Chromosomal Abnormalities

Cancer Screening, Population Health Screening, and Genetic Syndromes

  • Genomics Overview

    • Incorporates complex diseases and research.
    • Definition of Genome: All the genes present in the human body and how they divide and interact with each other and the environment.
    • Diseases influenced by both genetics and environment include:
    • Diabetes
    • Heart Disease
    • Cancer

  • Body Systems Overview

    • Understanding body systems will aid studying for exams.
    • Head to Toe Systems:
      • Neurological
      • Cardiac
      • Renal (Kidneys)
      • Abdominal organs
    • Example of how diabetes affects organs: Heart and kidneys.

  • Examination Strategies

    • Exam strategy: Remove two answer choices when faced with multiple-choice questions.
    • Take calm consideration on the remaining choices to associate with relevant medical knowledge.
    • Helps with answers during tests such as board exams.

  • Disease Processes

    • Neurological Issue: Various disorders (specifically Down Syndrome) that result from chromosomal anomalies.
    • Cardiac Issues: Complications in infants like septal defects where surgeries may be needed.
    • Septal defects lead to heart failure and irregular blood flow.

  • Down Syndrome

    • Characterized by an extra copy of chromosome 21 (47 instead of the typical 46).
    • Common Physical Features:
    • Flat nasal bridge
    • Slanting eyes
    • Large tongue
    • Crease in palm of the hand
    • Distinguishing Features:
    • Important to differentiate between Down Syndrome and Fetal Alcohol Syndrome (FAS):
      • FAS will present with smaller heads and distinct features not typical of Down Syndrome.

  • Chromosomal Anomalies

    • Defined as irregularities in chromosome shape or number, affecting autosomal and sex chromosomes.
    • Can arise during cell division processes.
    • Events leading to chromosomal anomalies:
    • Errors during pre-implantation or pregnancy.
    • Structural aberrations (deletions, inversions, translations).

  • Genetic Testing and Abnormalities

    • Importance of genetic testing in confirming disorders based on family history and symptoms.
    • Testing timelines for Down Syndrome:
    • Pre-natal blood tests start at 10 weeks up to 16-20 weeks gestation.
    • FISH test: FISH stands for Fluorescence In Situ Hybridization, confirming chromosomal abnormalities.

  • Screening and Blood Tests

    • Importance of ultrasound and blood work for diagnoses, looking for markers of abnormalities.
    • Increased fluid in the nuchal area may indicate conditions such as Down Syndrome.
    • Variations in office practices affecting testing timelines and procedures.

  • Genetic Disorders

    • Types of inherited disorders include gene mutations, deletions, and their related health implications.

  • Marfan Syndrome

    • Caused by a mutation of the FBN1 gene on chromosome 15.
    • Symptoms include:
    • Weak connective tissues, leading to skeletal abnormalities.
    • Common features include tall stature, long limbs, and vision issues.
    • Diagnosis includes echocardiograms for heart evaluation and monitoring of symptoms.

  • Neurofibromatosis

    • Identified by café-au-lait spots and tumors due to mutations on chromosome 17.
    • Diagnosis criteria involve spotting more than six café-au-lait spots and other clinical features.

  • Cystic Fibrosis

    • Caused by mutations in the CFTR gene, affecting chloride transport leading to thick mucus and affecting respiratory function.
    • Diagnosis via the sweat test (>60 mmoL indicative) to check chloride levels in sweat.

  • Tay-Sachs Disease

    • Mutation of the HEXA gene on chromosome 15.
    • Autosomal recessive disorder affecting GM2 ganglioside metabolism leading to neurodegenerative issues.
    • Higher incidence among Ashkenazi Jewish populations.

  • Sickle Cell Anemia

    • Hemoglobin S gene mutation leading to sickle-shaped RBCs.
    • Commonly affects individuals of African descent.
    • Inherited typically in an autosomal recessive fashion, details on symptoms and prevalence noted.

  • Turner Syndrome

    • Defined by monosomy X (45 chromosomes). Affects females predominantly, leads to various physical features such as short stature and lymphedema.
    • Random occurrence during reproductive cell division rather than inherited from parents.

  • Discussion on Nursing Interventions

    • Importance of early nursing intervention and family support in managing developmental outcomes for children with chromosomal abnormalities.
    • Mention of the essential role of education and available counseling services for affected families.

  • Conclusion

    • Review of persistent key concepts, differences in disorders, and implications for patient care and healthcare protocols.