Alzheimer's and Genes
Scientists do not yet fully understand what causes Alzheimer's disease (AD). However, the more they learn about Alzheimer's disease, the more they become aware of the important function genes play in the development of this devastating disease. If a person has one of these specific genes (the APOE e4 gene), he or she is said to have a risk factor for Alzheimer's disease. However, this does not mean that Alzheimer's disease is certain. Ongoing research is being performed to learn more about Alzheimer's and genes.
All living things are made up of basic units called cells, which are so tiny that you can only see them through the lens of a strong microscope. Most of the billions of cells in the human body have one nucleus that acts as a control center, housing our 23 pairs of chromosomes. A chromosome is a thread-like structure found in the cell's nucleus, which can carry hundreds, sometimes thousands, of genes. In humans, one of each pair of 23 chromosomes is inherited from each parent. The genetic material on these chromosomes is collectively referred to as the human genome. Scientists now believe that there are about 30,000 genes in the human genome.
Genes direct almost every aspect of the construction, operation, and repair of all living things. For example, genes contain information that determines eye and hair color and other traits inherited from our parents. In addition, genes ensure that we have two hands and can use them to do things, like play the piano.
Genes alone are not all-powerful. Most genes can do little until spurred on by other substances. Although they are necessary in their own right, genes basically wait inside the cell's nucleus for other molecules to come along and read their messages. These messages provide the cell with instructions for building a specific protein.
Proteins are essential building blocks in all cells. For example, bones, teeth, muscles, and blood are formed from different proteins. They help our bodies grow, work properly, and stay healthy. Amino acids are the building blocks of proteins. A gene provides the code, or blueprint, for the type and order of amino acids needed to build a specific protein. Sometimes a genetic mutation (or defect in a gene) can occur, leading to the production of a faulty protein. Faulty proteins can cause cell malfunction, disease, and death.
Scientists are studying genes to learn more about the proteins they make and what these proteins actually do in the body. They also hope to discover what illnesses are caused when proteins do not work correctly.