Rare diseases are a group of less common diseases, mostly of genetic origin, and mostly affect children. Although there are millions of people with rare diseases in Turkey and worldwide, due to the unique diversity of symptoms and the lack of available information on some of these diseases, patients might have difficulty receiving a diagnosis. Half of the people with rare diseases do not get a definitive diagnosis. In some cases, it may take many years to find the right doctor and the correct diagnosis method. Or patients may not be able to access the treatment and care they need due to misdiagnosis.
How can genetic diagnosis help in rare diseases?
It can help patients be directed to proper treatments and clinical trials.
It can provide information about the course of the disease, which symptoms can be seen at certain stages. Thus, it can help take precautions before some symptoms arise.
It enables the identification of family members at risk of being affected by the genetic change that causes the disease.
In the case of a planned pregnancy, it gives information about the risk of a rare disease.
Genetic Tests in Rare Diseases
Whole Exome Sequencing
There are about 20,000 genes in the human body. Certain parts of these genes provide the information needed to synthesize proteins responsible for regulating vital events in the body. Disease-causing changes in these protein-coding regions of genes can lead to genetic diseases. The vast majority of genetic diseases are caused by base mutations in regions that encode proteins.
The vast majority of rare diseases present with symptoms of different types and severity and are associated with changes in many genes. Whole Exome Sequencing analyzes the protein-coding regions of approximately 20,000 genes simultaneously. Exome sequencing provides rapid access to comprehensive information and shortens the diagnosis period.
Mikcoarray Analysis
The 20,000 genes in the human body are packed in 23 pairs of chromosomes. Some changes in these chromosomes, like the deletion or duplication of some DNA regions or changes in DNA copy number, can lead to genetic diseases. With Microarray Analysis, all chromosomes are analyzed simultaneously to detect DNA deletions, duplications, and copy number changes.
