NUR C202: Care of Mother and Child at Risk

NUR C202: Care of Mother and Child at Risk or with Problems (Acute and Chronic)

• Course is offered by Gina M. Dumawal RN, MAN at José Rizal University
• Course covers care for mothers and children at risk or with problems, both acute and chronic

Genetics and Genetic Counseling

• Genetics is the study of genes, heredity, and variations in living organisms
• Gregor Mendel is considered the father of Genetics
• The term "Genetics" was coined by William Bateson

Objectives

• Students will describe the nature of inheritance, patterns of recessive and dominant Mendelian inheritance, and common chromosomal aberrations causing physical or cognitive disorders.
• Students will assess a family's adjustment to the probability of inheriting a genetic disorder.
• Students will formulate nursing diagnoses related to genetic disorders.
• Students will plan nursing care related to potential genetic health alterations, such as assisting with amniocentesis.
• Students will implement nursing care like counseling families with genetic disorders.
• Students will evaluate expected outcomes for care effectiveness.
• Students will integrate knowledge of genetic inheritance with nursing process.

Introduction to Genetics

• The human body contains trillions of cells, each with a nucleus (except red blood cells).
• Each nucleus has 46 chromosomes, arranged in 23 pairs.
• One chromosome from each pair comes from each parent.
• Chromosomes are composed of tightly coiled DNA strands.
• Genes are segments of DNA containing instructions for making proteins.

Introduction to Genetics (More Detail)

• Genome: The complete set of genetic material in an organism (approximately 50,000 to 100,000).
• Normal Genome: Abbreviated as 46XX or 46XY, with additional details for chromosomal aberrations (e.g., Down syndrome as 47XX21 or 47XY21).
• Phenotype: An individual's outward appearance.
• Genotype: An individual's actual genetic makeup.
• Homozygous: A person having two identical genes for a trait on similar chromosomes.
• Heterozygous: A person having two different genes for a trait on similar chromosomes.
• Inherited/genetic disorders passed down from one generation to the next.

Karyotype

• A schematic representation of chromosomes, demonstrating their numbers and morphology.
• Hereditary: Characteristics (traits) derived from parents.
• Familial: Characteristics (traits) transmitted through generations.
• Congenital: Present at birth (not always genetically determined; examples include congenital syphilis, toxoplasmosis).

Introduction to Genetics (Genes, Chromosomes, DNA)

• Humans have 46 chromosomes (22 pairs of autosomes and 1 pair of sex chromosomes).
• Sperm and egg cells each carry 23 chromosomes.
• For each chromosome in a sperm cell, there's a similar chromosome in shape and function (autosome or homologous chromosome) in an egg cell.
• Two like genes (alleles) are paired (represented on autosomes) for each trait.
• The one chromosome that determines gender (sex).

Role of Nurse in Genetics

• Nurses encounter individuals/families impacted by genetic diseases.
• Nurses bridge patients and healthcare services.
• Nurses need a foundational knowledge of genetics.

Genetic Counseling and Interviewing

• Interview individuals with suspected genetic disorders.
• Gather detailed clinical histories (three generations) of family history.
• Refer individuals with genetic disorders to the appropriate doctor.

Planning, Screening, or Gene-Based Testing Programs

• Provide education about genetics and genetic testing.
• Create and interpret pedigree charts for genetic disorder analysis.
• Assess genetic risks, especially when combined with genetic testing.

Monitoring

• Following up on positive newborn genetic screening tests.
• Monitoring individuals with diagnosed genetic disorders.
• Supporting families facing genetic disorders.

Care

• Develop personalized plans of care and services for affected patients.
• Participate in public education initiatives about genetics.
• Maintain confidentiality and privacy of patient's genetic information.

Educational Role

• Educate individuals/families about the influence of genetics and environmental factors on health and disease.
• Assist family members in identifying Mendelian inheritance patterns (pedigree/family trees) of genetic disorders.

Impact of Genetic Conditions on Families

• Genetic conditions can have considerable social, physical/cognitive, and psychological impact on families.
• Genetic conditions can have significant financial implications and lead to economic hardship.

Impact of Genetic Conditions on Families (Continued)

• Guilt and/or emotional distress occur when individuals/families discover a genetic condition within their family.
• Depression can arise from genetic diagnoses and pregnancy and childbearing decisions.

Mechanism of Inheritance

• Mode of inheritance is how a genetic trait or disorder is passed down from one generation to the next.

Classification of Genetic Disorder

• Single gene (monogenic), or Mendelian, disorders: Disorders arising from a mutation in a single gene (e.g., cystic fibrosis, sickle cell anemia).
• Chromosomal disorders: Disorders caused by abnormalities in the number or structure of chromosomes (e.g., Down syndrome).
• Complex/multifactorial/polygenic disorders: Disorders resulting from a combination of genetic and environmental factors (e.g., cleft lip/palate, heart defects).

Single Gene or Monogenic Disorders/Mendelian Disorders

• Inherited in pairs (one gene from each parent).
• One gene may outweigh the other.
• The overshadowing gene is considered dominant.
• The gene overshadowed is considered recessive.
• Four common patterns of inheritance for Mendelian disorders: autosomal dominant, autosomal recessive, X-linked dominant, X-linked recessive.

Autosomal Dominant Pattern of Inheritance

• Location: Autosomes
• Required genes: One copy of the abnormal gene sufficient.
• Affected individuals: Both males and females equally.
• Pattern: Every affected individual will have an affected parent.
• Risk of transmission: 50% chance of transmitting to children (with an affected parent).

Autosomal Dominant Pattern of Inheritance (Continued)

• Two affected parents: 75% chance of the child being affected and 25% chance of the child being normal.

Autosomal Recessive Pattern of Inheritance

• Location: Autosomes
• Required genes: Two copies of the abnormal gene essential for expression.
• Affected individuals: Both males and females equally.
• Carrier state: An individual with one copy of the abnormal gene is a carrier.
• Pattern: Requires both parents to carry the abnormal gene for children to be at risk.

Autosomal Recessive Pattern of Inheritance (Continued)

• Heterozygous parents: Transmission to children - 25% chance of being affected, 50% chance of being a carrier, and 25% chance of being normal.
• One affected parent and one normal parent: The child will be unaffected heterozygotes

X-Linked Pattern of Inheritance

• Almost all sex-linked disorders are X-linked.
• Males with Y-linked mutations are generally infertile.
• Clinical expression different between males and females.
• Most X-linked disorders are recessive.
• Females with two X chromosomes: Expression of the disorder depends on whether it is dominant or recessive. Typically, females are carriers but less likely to be affected.
• Affected mothers (with a recessive X-linked trait): Affected male offspring only.

X-Linked Recessive Trait

• Location: X chromosome
• Required Genes: One abnormal gene in males; two in females (to show effects).
• Males: More likely to be affected (single X chromosome).
• Inheritance: Transmission through female carriers.

X-Linked Recessive Trait (Risks of Inheritance)

• Affected male, normal female: All sons normal; all daughters carriers.

Genetic Inheritance of a Disease (Multifactorial/Polygenic)

• Inheritance of a disease (multifactorial), result from numerous gene combinations, often combined with environmental factors.
• No clear hereditary pattern in these conditions.
• Can have an increased frequency in one sex vs. another (e.g., cleft palate).

Risk Factors for Genetic Disorders

• Family history of genetic disorders.
• Prior child with a genetic disorder.
• Parent with a chromosomal abnormality.
• Advanced maternal/paternal age.
• Multiple miscarriages/prior stillbirth.
• Prenatal exposure to harmful substances (alcohol, certain drugs, etc.).

Types of Disorders That Can be Seen During Pregnancy

• Single Gene/Mendelian disorders: Occur when a change in gene causes a disease (e.g., cystic fibrosis, sickle cell anemia, hemophilia).
• Chromosomal abnormalities: Involves extra or missing chromosomes, or structural changes (e.g., Down syndrome).
• Multifactorial/complex disorders: Results from a combination of genetic and environmental factors (e.g., heart defects, cleft lip/palate).
• Teratogenic disorders: Occur when a developing baby is exposed to harmful substances during pregnancy, causing abnormalities.

Testing for Genetic Disorders

• Screening tests: Estimate the risk of a genetic disorder.
• Diagnostic tests: Detect the presence or absence of a genetic disorder.
• These tests may involve blood, tissue, and/or fluid samples, as well as other procedures (e.g., amniocentesis, chorionic villus sampling). Advanced diagnostic techniques are available, such as fetal cell/blood sampling, chromosomal microarray analysis, and fetal genome sequencing.

Genetic Counseling

• Assess personal risk of having a child with a genetic disorder.
• Review testing options.
• Coordinate, interpret results of genetic screenings, and diagnostic tests.
• Offer emotional support and educational resources to families.
• Provide informed decision-making support for treatment plan and medical care.

Treatment for Fetal Genetic Disorders

• Treatment plans are individualized according to the diagnosis, pregnancy progression, and family preferences.
• This treatment ranges from therapies during pregnancy to postnatal surgical and medical interventions.
• A multidisciplinary healthcare team is often involved in treatment and care (e.g., medical and genetic specialists).
• Supports for families are also essential.