Genetics and health: how heredity affects 50% of your condition

Genetics and health: how heredity affects 50% of your condition

I. Fundamentals of human genetics and its health connection

A. DNA: Life drawing

1. DNA structure: DNA (deoxyribonucleic acid) is a molecule containing genetic instructions necessary for the development, functioning and reproduction of all known living organisms and many viruses. It is a double spiral consisting of two threads, each of which consists of nucleotides.

2. Nucleotihoti: Each nucleotide consists of three components:

   • Deoxyribose: Sugar that forms the basis of the structure of nucleotide.
   • Phosphate group: A group of atoms connecting nucleotides in a DNA chain.
   • Nitrogenic base: One of the four types of molecules: adenin (A), Timin (t), guanine (G) and cytosine (C). These bases are connected to each other according to the principle of complementarity (A C T, G C C), forming the “steps” of a double spiral.

3. Genetic code: The sequence of nitrogenous bases in DNA determines the genetic code. This code contains instructions for protein synthesis. Three consistent nucleotide (codon) encode one amino acid. Amino acids are connected in a certain order for the formation of protein.

4. DNA replication: The process of copying DNA required for cell division. Enzymes, such as DNA polymerase, provide accurate copying of each DNA thread, which allows cells to transmit genetic information to their descendants.

5. Transcription and broadcast:

   • Transcription: The process in which the information encoded in the DNA is corresponded to the RNA molecule (ribonucleic acid). RNA differs from DNA in that it contains ribosa sugar instead of deoxyribose and uracil (u) instead of tymin (t).
   • Broadcast: The process in which the information encoded in RNA is used to synthesize protein. Ribosomes, cellular organelles, read RNA and connect amino acids in accordance with the genetic code.

B. Genes: units of heredity

1. Definition gene: The gene is a DNA section that encodes a certain function, most often the synthesis of a certain protein. Proteins perform a variety of functions in the body, including structural, enzymatic, hormonal and transport.

2. Locus gene: The locus is a specific location of the gene on the chromosome.

3. Allleli: Alleles are various options for the same gene. For example, a gene that determines the color of the eyes can have alleles encoding brown or green.

4. Genotype and phenotype:

   • Genotype: The genetic constitution of the individual, that is, the totality of all the alleles that he carries.
   • Phenotype: The observed characteristics of the individual, such as eye color, growth, or tendency to certain diseases. The phenotype is the result of the interaction of the genotype and environmental factors.

5. Dominant and recessive alleles:

   • Dominant allele: Allele, which manifests itself in the phenotype, even if there is only one copy.
   • Recessive allele: Allele, which manifests itself in the phenotype only if there are two copies.

C. Chromosomes: DNA packaging

1. The structure of the chromosomes: Chromosomes are structures containing DNA, tightly packed around proteins called histones. They are located in the cage core.

2. The number of chromosomes in humans: A person usually has 46 chromosomes organized in 23 pairs. One copy of each pair is inherited from the mother, and the other from the father.

3. Autosomas and sex chromosomes:

   • Autosomes: 22 pairs of chromosomes not related to the definition of gender.
   • Sexual chromosomes: One pair of chromosomes determining the floor of the individual. In women, these are two X-chromosomes (XX), and in men one X-chromosome and one Y-chromosome (XY).

4. Karyotype: A cariot is an ordered representation of the chromosomes of the individual. It is used to detect chromosomal anomalies.

D. Mutations: Changes in the genetic code

1. Determination of mutation: A mutation is a change in the sequence of DNA. Mutations can occur spontaneously or be caused by the influence of environmental factors, such as radiation or chemicals.

2. Types of mutations:

   • Particular mutations: Changes in one nucleotide. They can be replacements, inserts or deeds.
   • Inserts and deletions: Adding or removing nucleotides to the DNA sequence.
   • Chromosomal mutations: Changes in the structure or quantity of chromosomes. These include deletions, duplications, inversions and translocations.

3. The influence of mutations on health: Mutations can be neutral, useful or harmful. Harmful mutations can cause genetic diseases.

E. Heredity: Transfer of genetic information

1. Mendel’s laws:

   • The law of the first -generation uniformity: When crossing homozygous individuals according to alternative signs in the first generation, offspring will be uniform on this basis.
   • The law of splitting signs in the second generation: When crossing the first generation hybrids in the second generation, there is a splitting of signs in a certain ratio (usually 3: 1).
   • Independent inheritance law: Genes of different signs are inherited independently of each other if they are located on different chromosomes.

2. Types of inheritance:

   • Autosomal dominant inheritance: The disease manifests itself if a person has at least one copy of the mutant gene on an autosome.
   • Autosomal recessive inheritance: The disease manifests itself if a person has two copies of a mutant gene on an autosome.
   • X-linked dominant inheritance: The disease is manifested in women with at least one copy of the mutant gene on the X-chromosome, and in men who have a mutant gene on their X-chromosome.
   • X-linked recessive inheritance: The disease is manifested in men with a mutant gene on their X-chromosome, and in women with two copies of the mutant gene on the X-chromosomes.
   • Y-linked inheritance: The disease is transmitted only from father to son, since the Y chromosome is present only in men.
   • Mitochondrial inheritance: Mitochondria, organelles that provide the cell with energy have their own DNA. Mutations in mitochondrial DNA are transmitted only from mother to offspring.

II. Genetic diseases and predisposition

A. Monogenic diseases

1. Determination of a monogenic disease: The disease caused by a mutation in one gene.

2. Examples of monogenic diseases:

   • MukoviScidoz: Autosomal recessive disease caused by a mutation in the CFTR gene. Leads to the accumulation of thick mucus in the lungs, pancreas and other organs.
   • Sickle -cell anemia: Autosomal recessive disease caused by a mutation in the HBB gene. Leads to the formation of abnormal red blood cells that have a sickle form.
   • Phenylketonuria: Autosomal recessive disease caused by a mutation in the PAH gene. Leads to the accumulation of phenylalanine in the blood, which can damage the brain.
   • Gentington disease: Autosomal dominant disease caused by a mutation in the HTT gene. Leads to a progressive neurodegenerative disorder.
   • Hemophilia: X-linked recessive disease caused by a mutation in genes encoding blood coagulation factors. Leads to a violation of blood coagulation.

3. Diagnosis of monogenic diseases: Diagnosis can be performed using genetic testing, which allows you to identify mutations in specific genes.

B. Chromosomal abnormalities

1. Determination of chromosomal anomaly: Change in the structure or quantity of chromosomes.

2. Examples of chromosomal anomalies:

   • Down Syndrome (Trisomy 21): The presence of an additional copy of the 21st chromosome. Leads to mental retardation, characteristic features of the face and other health problems.
   • Turner syndrome (monosomy x): The absence of one X-chromosome in women. Leads to infertility, low stature and other health problems.
   • Klainfelter syndrome (XXY): The presence of an additional X-chromosome in men. Leads to infertility, gynecomastia and other health problems.

3. Diagnosis of chromosomal anomalies: Diagnostics can be performed using cariotyping or other methods of genetic analysis, such as FISH (fluorescent hybridization in situ).

C. multifactorial diseases

1. Determination of a multifactorial disease: The disease caused by the interaction of genetic factors and environmental factors.

2. Genetic predisposition: The presence of genetic options that increase the risk of the development of the disease. These options can be common in populations, but only in people who have a certain combination of genes and exposed to certain environmental factors develop a disease.

3. Environmental factors: Factors that can contribute to the development of multifactorial diseases include a diet, lifestyle, exposure to toxins and infections.

4. Examples of multifactorial diseases:

   • Cardiovascular diseases: High blood pressure, coronary heart disease, stroke. Genetic predisposition and environmental factors, such as smoking, improper nutrition and lack of physical activity, play an important role.
   • Type 2 diabetes: A combination of genetic predisposition and environmental factors, such as obesity, improper nutrition and lack of physical activity.
   • Cancer: Many types of cancer have a genetic predisposition, but environmental factors, such as smoking, the effect of ultraviolet radiation and certain chemicals, also play an important role.
   • Autoimmune diseases: Rheumatoid arthritis, multiple sclerosis, Crohn’s disease. Genetic predisposition and environmental factors, such as infections and stress, can contribute to the development of these diseases.
   • Mental disorders: Schizophrenia, bipolar disorder, depression. Genetic predisposition and environmental factors, such as stress and injuries, can play an important role.

5. Genetic risk assessment: Genetic risk assessment can be performed using genetic testing and analysis of family history. However, it is important to understand that the presence of a genetic predisposition does not mean that a person will necessarily get sick.

III. The role of genetics in specific aspects of health

A. Genetics and metabolism

1. The influence of genes on metabolism: Genes play an important role in the regulation of metabolic processes, such as digestion of food, assimilation of nutrients, energy production and detoxification.

2. Genetic options and metabolic diseases: Genetic options can affect metabolism and increase the risk of developing metabolic diseases, such as:

   • Lactose intolerance: The inability to digest lactose, sugar contained in milk. It is caused by a decrease in the activity of the lactase enzyme.
   • Celiacia: Autoimmune disease caused by a reaction to gluten, protein contained in wheat, rye and barley.
   • Hemochromatosis: The disease characterized by excessive accumulation of iron in the body.
   • Hypercholesterolemia: High blood cholesterol.

3. Personalized nutrition: Information about genetic options can be used to develop personalized diets that take into account individual needs and increase the effectiveness of nutrition.

B. Genetics and immunity

1. The influence of genes on the immune system: Genes play an important role in the development and functioning of the immune system, which protects the body from infections and other threats.

2. Genetic options and immune diseases: Genetic options can affect the immune system and increase the risk of developing immune diseases, such as:

   • Autoimmune diseases: Rheumatoid arthritis, multiple sclerosis, Crohn’s disease.
   • Immunodeficiency: States in which the immune system does not function properly, which makes a person more susceptible to infections.
   • Allergies: Excessive reaction of the immune system to harmless substances, such as pollen, food or medicine.

3. Genetics and susceptibility to infections: Genetic factors can affect susceptibility to infections, for example, HIV, hepatitis and influenza.

C. Genetics and cardiovascular system

1. The influence of genes on the cardiovascular system: Genes play an important role in the development and functioning of the cardiovascular system, including the heart, blood vessels and blood.

2. Genetic options and cardiovascular diseases: Genetic options can affect the cardiovascular system and increase the risk of developing cardiovascular diseases, such as:

   • Ichemic heart disease: The disease caused by narrowing of the coronary arteries that supply the heart with blood.
   • Stroke: Brain damage caused by impaired blood supply.
   • Hypertension: High blood pressure.
   • Cardiomyopathy: The disease of the heart muscle.

3. Genetic testing to assess the risk of cardiovascular diseases: Genetic testing can be used to assess the risk of cardiovascular diseases and develop prevention strategies.

D. Genetics and Cancer

1. The influence of genes on the development of cancer: Genes play an important role in the regulation of cellular growth, division and death. Mutations in these genes can lead to cancer.

2. Oncogen and tumor-soup genes:

   • Oncogenes: Genes that contribute to the growth and division of cells. Mutations in oncogenes can lead to their activation and uncontrolled cell growth.
   • Tumor Suppressors genes: Genes that suppress the growth and division of cells. Mutations in the tumor-soup genes can lead to their inactivation and uncontrolled cell growth.

3. Hereditary cancer: Some types of cancer have a hereditary predisposition, that is, they are transmitted from generation to generation.

4. Examples of genes related to hereditary cancer:

   • BRCA1 I BRCA2: Genes associated with an increased risk of breast cancer and ovarian cancer.
   • TP53: A gene associated with an increased risk of various types of cancer.
   • MLH1, MSH2, MSH6 и PMS2: Genes associated with an increased risk of colorectal cancer.

5. Genetic testing to assess the risk of cancer: Genetic testing can be used to assess the risk of cancer and develop prevention and early detection strategies.

E. Genetics and mental health

1. The influence of genes on mental health: Genes play an important role in the development and functioning of the brain, as well as in the regulation of mood, behavior and cognitive functions.

2. Genetic options and mental disorders: Genetic options can affect mental health and increase the risk of mental disorders, such as:

   • Schizophrenia: Chronic mental disorder characterized by impaired thinking, perception and behavior.
   • Bipolar disorder: Mental disorder characterized by fluctuations in the mood between depression and mania.
   • Depression: Disorder of mood, characterized by a sense of sadness, loss of interest and energy.
   • Alarm disorders: Disorders characterized by excessive anxiety and fear.
   • Autism: Development of development, characterized by difficulties in social interaction and communication.

3. The interaction of genes and the environment in the development of mental disorders: Mental disorders are often the result of the interaction of genetic predisposition and environmental factors, such as stress, injuries and social insulation.

IV. Genetic Testing: A tool for understanding heredity and health

A. Types of genetic testing

1. Diagnostic testing: It is used to confirm or exclude a genetic disease in a person with symptoms.

2. Predictive testing: It is used to assess the risk of developing a genetic disease in the future.

3. Prenatal testing: It is used to detect genetic diseases in the fetus during pregnancy.

4. Preimplantation genetic diagnostics (PGD): It is used to detect genetic diseases in embryos created in vitro before implantation into the uterus.

5. Newborns screening: It is used to detect genetic diseases in newborns so that you can start treatment as early as possible.

6. Pharmacogenetic testing: It is used to determine how a person will respond to certain drugs based on his genetic profile.

7. Paternity testing: Used to establish biological paternity.

8. Full -beam sequencing (WGS) and full -explosive sequencing (WES): Methods that allow you to analyze almost all the genetic information of a person (WGS) or only encoding proteins areas of genes (WES). They are used to identify rare or non -diagnosed diseases, as well as for scientific research.

B. Genetic testing methods

1. PCR (polymerase chain reaction): The method of amplification (multiplication) of certain DNA sections, which allows you to analyze them in more detail.

2. DNA sequencing: The method for determining the sequence of nucleotides in DNA.

3. Fish (fluorescent hybridization in situ): The method used to detect chromosomal abnormalities.

4. DNA microchips (DNA microta): The method used to analyze genes expression or to identify genetic options.

5. Cariotipirani: Visualization of chromosomes to detect chromosomal anomalies.

C. Ethical, legal and social issues of genetic testing

1. Confidentiality: It is important to ensure the confidentiality of genetic information.

2. Discrimination: There is a risk of discrimination based on genetic information, for example, in the field of employment or insurance.

3. Informed consent: It is important to get informed consent before the genetic testing.

4. Interpretation of the results: It is important that the results of genetic testing are correctly interpreted and explained to the patient.

5. Accessibility: It is important to ensure the availability of genetic testing for everyone who needs it.

V. The future of genetics and health

A. Personalized medicine

1. Determination of personalized medicine: The approach to treatment, which takes into account individual genetic, environmental and lifestyle factors.

2. The role of genetics in personalized medicine: Genetic information can be used to select the most effective treatment for a particular patient.

3. Examples of the use of personalized medicine:

   • Pharmacogenetics: The selection of drugs based on the genetic profile of the patient.
   • Target Cancer Therapy: Treatment of cancer aimed at specific genetic mutations in tumor cells.
   • Prevention of diseases: Development of strategies for the prevention of diseases based on genetic predisposition.

B. General therapy

1. Determination of genetic therapy: The method of treating genetic diseases by introducing a healthy copy of the gene into the patient’s cells.

2. Types of genetic therapy:

   • In vivo gene therapy: The introduction of the gene directly into the patient’s body.
   • EX Vivo Gene therapy: Modification of cells outside the body, and then introducing them back to the patient.

3. Examples of genetic therapy:

   • Treatment of spinal muscle atrophy (SMA): Gene therapy aimed at replacing the defective gene SMN1.
   • Treatment of some types of leukemia: Gene therapy aimed at modifying immune cells so that they attack cancer cells.

4. Problems of genetic therapy:

   • Safety: It is important to ensure the safety of genetic therapy and avoid undesirable side effects.
   • Efficiency: It is important that gene therapy is effective and ensures a long -term improvement in the patient’s condition.
   • Accessibility: It is important to ensure the availability of genetic therapy for everyone who needs it.

C. CRISPR-CAS9 and genome editing

1. CRISPR-CAS9 definition: Genoma editing technology that allows you to accurately edit DNA sequences.

2. Application CRISPR-CAS9:

   • Study of genetic diseases: CRISPR-CAS9 is used to create models of genetic diseases in laboratory conditions.
   • Development of new treatment methods: CRISPR-CAS9 can be used to develop new methods of treating genetic diseases.
   • Creation of genetically modified organisms: CRISPR-CAS9 can be used to create genetically modified organisms, for example, to improve crop yields.

3. Ethical questions CRISPR-CAS9:

   • Editing the embryo line: Editing the genome of sperm, eggs or embryos can lead to changes that will be transmitted from generation to generation.
   • Unforeseen consequences: The genome editing may have unforeseen consequences for human health and the environment.

D. Preventive genomic

1. Definition of prevention genomics: The use of genetic information to prevent diseases before their development.

2. Application of preventive genomics:

   • Newborns screening: Identification of genetic diseases in newborns so that you can start treatment as early as possible.
   • Risk assessment of diseases: Assessment of the risk of developing diseases based on genetic predisposition.
   • Personalized prevention strategies: Development of strategies for the prevention of diseases based on genetic predisposition.

E. Artificial intelligence and genetics

1. The role of artificial intelligence in genetics: Artificial intelligence (AI) can be used to analyze large volumes of genetic data and identify patterns that would be difficult to detect manually.

2. The use of AI in genetics:

   • Identification of genetic options associated with diseases.
   • The prediction of the risk of developing diseases based on genetic information.
   • Development of new drugs and treatment methods.
   • Personalized medicine.

VI. Practical tips for managing genetic risk

A. Family history and genealogical tree

1. The meaning of family history: Family history is an important tool for assessing genetic risk.

2. Drawing up the genealogical tree: The compilation of the genealogical tree allows you to identify the laws of inheritance of diseases in the family.

3. Discussion of family history with a doctor: It is important to discuss the family story with a doctor so that he can evaluate the genetic risk and recommend appropriate measures.

B. A healthy lifestyle

1. Influence of lifestyle on health: A healthy lifestyle can reduce the risk of developing many diseases, even in the presence of a genetic predisposition.

2. Recommendations on a healthy lifestyle:

   • Proper nutrition: The use of a diverse and balanced diet rich in fruits, vegetables and whole cereals.
   • Regular physical activity: Regular sports or physical exercises.
   • Refusal of smoking and abuse of alcohol.
   • Maintaining a healthy weight.
   • Stress management.
   • Regular medical examinations and screening.

C. Genetic counseling

1. What is genetic counseling: The process in which the genetic consultant provides information about genetic diseases, evaluates genetic risk and helps to make reasonable decisions.

2. When you should contact a genetic consultant:

   • If the family has cases of genetic diseases.
   • If you plan a pregnancy and want to evaluate the risk of a child with a genetic disease.
   • If you need to decide on the conduct of genetic testing.
   • If you are diagnosed with a genetic disease and you need information about its treatment and management.

D. Ethical considerations

1. Making reasonable decisions: It is important to make reasonable decisions on genetic testing and treatment, taking into account ethical, legal and social aspects.

2. Confidentiality: It is important to observe the confidentiality of genetic information.

3. Responsibility: It is important to bear responsibility for the use of genetic information.

VII. Conclusion.