Hereditary disorders occur due to genetic mutations. These gene mutations or variations increase an individual’s risk of developing some genetic disease. A parent carrying such distorted genes can pass it on to their offspring.
The gene transfer can increase the likelihood of developing some genetic conditions in the offspring. However, the individual doesn’t need to develop some condition just because they carry the gene mutation.
Genetic mutations or variations can be chromosomal, complex (multifactorial), and single-gene (monogenic) disorders. In this blog, we will discuss the types of hereditary conditions observed in families.
About Hereditary Diseases
Hereditary diseases or genetic disorders are a result of genetic mutation that affects your genes. Genes are basic units of inheritance and are made up of sequences of DNA (deoxyribonucleic acid). Mutations or variations can alter the genetic material.
Genes consist of information that determines your characteristics and traits. Some specific variations or mutations in the genes affect the overall health of an individual. Certain mutations can increase the chances of genetic predisposition due to mutated genetic makeup.
An individual inherits such mutated gene makeup from one or both parents. Passing on such genes raises the individual’s risk of developing genetic diseases. In some cases, the symptoms are visible at birth, while others develop over time.
List Of Some Common Heredity Diseases
Different types of genetic disorders come under four different categories. These categories are single-gene disorders, chromosomal disorders, multifactorial inheritance disorders, and mitochondrial disorders.
Let us have a look at the Hereditary Diseases according to the category:
Single-Gene Disorders
- Sickle Cell Anemia: The condition affects the shape of red blood cells, thereby hindering the supply of oxygen in the body.
- Cystic Fibrosis: It affects the lungs, pancreas, digestive system, and other organs due to the buildup of thick, sticky mucus in them.
- Hemophilia: In this condition, blood does not clot normally as its ability to clot impairs.
- Huntington’s Disease: This leads to early decay and progressive breakdown of nerve cells of the brain.
- Tay-Sachs Disease: This disorder affects nerve cells in the brain and spinal cord because of the buildup of fatty acids.
- Duchenne Muscular Dystrophy: The condition contributes to muscle degeneration and weakness.
- Phenylketonuria (PKU): Characterized by the body’s ability to metabolize phenylalanine, causing too much Phenylketonuria in the body. It produces a musty odor in the breath, skin, or urine.
Chromosomal Disorders
- Down Syndrome: Characterized by abnormal physical features and intellectual disorders due to an extra chromosome 21.
- Klinefelter Syndrome: The syndrome affects males, due to the presence of an extra X chromosome (XXY).
- Turner Syndrome: This condition affects females, caused by a missing or incomplete X chromosome.
- Trisomy 13 (Patau Syndrome): It is the result of an extra chromosome 13 in some or all body cells.
- Trisomy 18 (Edwards Syndrome): It results from an additional copy of chromosome 18.
Multifactorial Inheritance Disorders
- Heart Disease: A combination of multiple genetic and environmental factors that influence heart-related issues.
- Diabetes: Type 1 and Type 2 diabetes, both have genetic components.
- Colon Cancer: Some gene mutations can increase the risk of colorectal cancer significantly.
- Breast Cancer: Passing on or inheriting certain genes such as BRCA1 and BRCA2 increases the risk of developing this condition.
- Alzheimer’s Disease: Some individuals carry certain genes like APOE, which genetically predisposes them to the risk of Alzheimer’s.
Mitochondrial Disorders
- Leber’s Hereditary Optic Neuropathy (LHON): This condition is associated with vision loss as it affects the optic nerves.
- Mitochondrial Myopathy: The condition affects the muscles of arms and legs and impacts the nervous system.
- Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes (MELAS): This disorder impacts the function of the brain and muscles.
Genetic Testing For Heredity Diseases
Genetic testing for detecting hereditary diseases involves analyzing DNA. These tests identify mutations or variations that may indicate a risk for specific genetic disorders.
Genetic testing can provide valuable information regarding the genetic makeup of individuals and families. It assesses one’s risk of developing genetic disorders due to gene changes.
Types Of Genetic Testing For Hereditary Diseases
Different types of genetic testing for hereditary diseases are as follows:
- Diagnostic Testing: This test helps identify if there is a possibility of developing some genetic condition in the future in an asymptomatic individual. Healthcare professionals suggest such tests for indicating genetic conditions such as sickle cell anemia, cystic fibrosis, Huntington’s disease, and so on.
- Predictive Testing: This test anticipates any genetic disorder by detecting specific genetic mutations. It checks for specific mutations (e.g., BRCA1 and BRCA2) for predicting certain types of cancers. In the case of Huntington’s disease detection, the test involves analyzing the HTT gene.
- Prenatal Testing: This test helps analyze the fetal DNA to check for gene mutations before birth. It helps with critical decision-making. With the help of test results, the healthcare provider and parents can decide and plan further lines of action. Prenatal test involves invasive as well as non–invasive techniques. Non-invasive prenatal test (NIPT) is the safest for fetal health.
- Carrier Testing: This test helps determine whether an individual is carrying a single copy of a gene mutation. When present in two copies, it can lead to a genetic disorder.
- Newborn Screening: This technique allows for determining any genetic mutation early in life. Early detection can enable planning treatment and management strategies. It involves screening for congenital hypothyroidism, phenylketonuria (PKU), and sickle cell disease. The list of genetic tests for analyzing hereditary diseases is not limited to this. You can consult a healthcare provider who can inform you about other tests and provide much-needed guidance.
Conclusion
Genetic testing for hereditary diseases is a transformative tool in modern medicine. It offers significant benefits for disease prevention, early diagnosis, effective management, and personalized healthcare. There are some limitations and considerations too.
You should always approach genetic testing with careful consideration. Before going for it, you must be aware of its ethical, psychological, and social impacts. Therefore, it is essential to consult a healthcare professional or genetic professional who can provide guidance and counseling.
