A single-gene disorder is a disease caused by a mutation in a single gene within a person's DNA. This mutation can disrupt the normal function of the gene, leading to a variety of health problems.
Understanding Single-Gene Disorders
These disorders occur because our bodies have over 20,000 genes that direct a wide variety of functions. When a single one of these genes develops an alteration, it can lead to significant health issues. According to the provided reference, "Single-gene disorder is a disease caused by a known alteration or mutation in one of more than 20.000 genes in nearly every cell in the body."
How Single-Gene Disorders are Inherited
Single-gene disorders can be inherited in several ways:
- From both parents: When both parents carry a mutation in the same gene, there is a risk that their children will inherit the affected copy of the gene from each of them, leading to the manifestation of the disease.
- From a single parent: It's possible to inherit a mutated gene from only one parent, leading to the disorder. The severity of the condition may vary depending on whether the disorder is dominant or recessive and can also depend if it is inherited by the sex chromosomes.
- Through generations: Single-gene disorders can pass through a family over several generations, with individuals potentially carrying the affected gene without experiencing symptoms themselves.
Examples of Single-Gene Disorders
There are thousands of known single-gene disorders, including:
- Cystic Fibrosis: Affects the lungs and digestive system.
- Sickle Cell Anemia: Impacts red blood cells and their ability to carry oxygen.
- Huntington's Disease: Causes progressive damage to nerve cells in the brain.
- Phenylketonuria (PKU): Prevents proper metabolism of an amino acid, requiring a special diet.
Diagnosis and Management
Diagnosing single-gene disorders often involves genetic testing and family history analysis. Management usually depends on the specific disease, but may include:
- Medications to manage symptoms
- Specialized diets
- Surgery
- Gene therapy (for some conditions)
Key Takeaway
Single-gene disorders are a group of diseases caused by changes in single genes, highlighting the complexity and fragility of our genetic makeup. They can be inherited, are often serious, and are sometimes treatable.
