Overview of Genetic Disorders

Overview of Genetic Disorders

Genetic disorders are medical conditions caused by abnormalities in an individual's DNA. These disorders can result from mutations in a single gene, chromosomal abnormalities, or complex interactions between multiple genes and environmental factors. They can be inherited from parents or arise due to spontaneous mutations.

Types of Genetic Disorders

1. Single-Gene Disorders (Mendelian Disorders)

These disorders occur due to mutations in a single gene and follow Mendelian inheritance patterns (dominant, recessive, or X-linked). Examples include:

• Cystic Fibrosis (CF) – Autosomal recessive disorder affecting the lungs and digestive system.

• Sickle Cell Anemia – Autosomal recessive disorder causing misshaped red blood cells.

• Huntington’s Disease – Autosomal dominant disorder leading to neurodegeneration.

• Hemophilia – X-linked recessive disorder affecting blood clotting.

2. Chromosomal Disorders

These disorders arise due to structural or numerical abnormalities in chromosomes. Examples include:

• Down Syndrome (Trisomy 21) – Presence of an extra chromosome 21, causing developmental delays.

• Turner Syndrome (45, X) – Affects females due to the absence of one X chromosome, leading to growth and reproductive issues.

• Klinefelter Syndrome (47, XXY) – Affects males due to an extra X chromosome, causing infertility and other symptoms.

3. Multifactorial (Complex) Disorders

These disorders result from interactions between multiple genes and environmental factors. Examples include:

• Diabetes Mellitus (Type 2)

• Hypertension

• Coronary Heart Disease

• Cancers (Breast Cancer, Colorectal Cancer, etc.)

4. Mitochondrial Disorders

Caused by mutations in mitochondrial DNA (mtDNA), these disorders are inherited maternally. Examples include:

• Leber’s Hereditary Optic Neuropathy (LHON) – Leads to vision loss.

• Mitochondrial Myopathy – Affects muscle function.