Tag: hemophilia

5 Most common Genetic Disorders

Here are five of the most common genetic disorders, along with a brief overview of each:

  1. Down syndrome: Down syndrome is caused by an extra copy of chromosome 21. This leads to intellectual disability, characteristic facial features, and a range of physical health problems such as heart defects, digestive issues, and hearing loss. It is the most common chromosomal disorder and affects approximately 1 in every 700 babies born.
  2. Cystic fibrosis: Cystic fibrosis is caused by mutations in the CFTR gene, which provides instructions for making a protein that regulates the flow of salt and fluids in and out of cells. This leads to a buildup of thick, sticky mucus in the lungs, pancreas, and other organs, which can cause breathing problems, digestive issues, and other health problems. It affects approximately 1 in every 2,500 to 3,500 newborns in the United States.
  3. Sickle cell anemia: Sickle cell anemia is caused by mutations in the HBB gene, which provides instructions for making a protein called hemoglobin. This leads to misshapen red blood cells that can cause a range of health problems such as anemia, pain, and organ damage. It is most common in people of African descent and affects approximately 1 in every 365 African American babies born in the United States.
  4. Huntington’s disease: Huntington’s disease is caused by mutations in the HTT gene, which provides instructions for making a protein called huntingtin. This leads to the gradual destruction of nerve cells in the brain, which can cause a range of symptoms such as movement problems, cognitive decline, and psychiatric symptoms. It is an inherited disorder and affects approximately 1 in every 10,000 people worldwide.
  5. Hemophilia: Hemophilia is caused by mutations in genes that provide instructions for making proteins that are necessary for blood clotting. This can lead to prolonged bleeding after injury or surgery, as well as internal bleeding that can damage organs and tissues. There are two main types of hemophilia, hemophilia A and hemophilia B, which are caused by mutations in different genes. Hemophilia A affects approximately 1 in every 5,000 to 10,000 males born, while hemophilia B affects approximately 1 in every 25,000 males born.

Monogenic Mendelian inheritance

Monogenic Mendelian inheritance, also known as single-gene inheritance, is a type of inheritance pattern in which a trait or disorder is determined by a single gene. These genes are typically located on the autosomal chromosomes (the non-sex chromosomes), and can be inherited in a predictable manner according to the laws of Mendelian genetics.

Mendelian genetics describes how traits are passed down from one generation to the next through the inheritance of genes from parents. There are three main types of Mendelian inheritance: autosomal dominant, autosomal recessive, and X-linked inheritance.

In autosomal dominant inheritance, an individual only needs to inherit one copy of the dominant gene from one parent to express the trait or disorder. The gene is expressed even if only one copy is present in the individual’s genome. For example, Huntington’s disease is a rare neurodegenerative disorder that is caused by a single dominant gene.

In autosomal recessive inheritance, an individual needs to inherit two copies of the recessive gene (one from each parent) to express the trait or disorder. The gene is only expressed if both copies are present. Examples of recessive disorders include sickle cell anemia and cystic fibrosis.

In X-linked inheritance, the gene is located on the X chromosome. Males have one X chromosome and one Y chromosome, while females have two X chromosomes. Because males have only one X chromosome, they are more likely to express a disorder caused by a recessive gene on the X chromosome. Examples of X-linked disorders include hemophilia and color blindness.

In summary, monogenic Mendelian inheritance refers to the inheritance of a trait or disorder that is determined by a single gene. The pattern of inheritance can be autosomal dominant, autosomal recessive, or X-linked, and can be predicted using the laws of Mendelian genetics.