DNA diseases, also known as genetic disorders, are primarily caused by alterations or abnormalities in an individual's DNA sequence or structure.
Types of DNA Mutations and Chromosomal Abnormalities
Several factors contribute to these alterations, ultimately leading to the development of various genetic diseases:
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Gene Mutations: A mutation is a change in the DNA sequence of a gene.
- Point Mutations: These involve a change in a single nucleotide base within a gene.
- Frameshift Mutations: Insertions or deletions of nucleotides that are not multiples of three can alter the reading frame of the genetic code during protein synthesis.
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Chromosomal Deletions: This refers to the loss of a segment of a chromosome, resulting in the absence of certain genes.
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Chromosomal Translocations: Occur when a segment of one chromosome breaks off and attaches to another chromosome.
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Aneuploidy: An extra or missing chromosome, leading to an abnormal number of chromosomes in a cell. Examples include Trisomy 21 (Down Syndrome) and Turner Syndrome.
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Sex Chromosome Abnormalities: These involve an abnormal number of sex chromosomes (X and Y). Examples include Klinefelter syndrome (XXY) and XYY syndrome.
How These Changes Lead to Disease
These genetic changes can disrupt the normal function of genes and proteins, leading to a wide range of disorders. The specific symptoms and severity of a DNA disease depend on the affected gene or chromosome and the nature of the alteration. For example:
- A mutation in a gene responsible for producing a vital enzyme can lead to metabolic disorders.
- A deletion of a region of a chromosome can result in multiple developmental abnormalities.
Causes of Genetic Changes
The alterations to the DNA can happen because of:
- Inherited Mutations: Passed down from parents to offspring.
- Spontaneous Mutations: Occur randomly during DNA replication or cell division.
- Environmental Factors: Exposure to mutagens (e.g., radiation, certain chemicals) can increase the risk of DNA damage.
