Genetic disorders are caused by mutations in genes, which are the basic units of heredity. These mutations affect a gene’s ability to form proteins that carry out vital functions.
Some genetic conditions are present from birth, and others develop later in life. Most are inherited following precise rules.
Many of these disorders are treated with nutrition counseling or dietary supplements, physical therapy, and blood transfusions. Other treatments may include specialized care.
Huntington’s disease
Huntington’s disease is a hereditary neurological disorder that causes brain cells to break down. It leads to movement and cognitive problems that worsen over time, resulting in a loss of control of movements and thinking skills. Eventually, patients lose the ability to take care of themselves and need to be completely dependent on others for help. The condition is caused by a single mutated gene. Researchers are now working to develop ways to prevent and treat the disease, including gene therapy.
The symptoms of the disease include chorea, cognitive impairment, and psychiatric disturbances. It also can cause swallowing difficulties and a loss of balance and coordination. In the early stages, symptoms are similar to Parkinson’s disease.
There is no cure for Huntington’s disease, but doctors can prescribe medications to treat the symptoms. These can include antidepressants and cholinesterase inhibitors. Some patients may benefit from physical and occupational therapy. Others might need to be placed in a nursing home or hospice.
Scientists are now working to develop ways to prevent and cure Huntington’s disease by using CRISPR-Cas9 technology to target the mutated gene. In a mouse study, scientists used this technique to cut out the defective gene and restore normal function. The results were promising, but further tests are needed in people to determine whether the technique is safe and effective in humans.
People with a family history of the disease should consider genetic testing to find out if they have a mutation in the HD gene. A genetic counselor can explain the process and results. They can also discuss options for family planning, such as prenatal testing or in vitro fertilization with donor sperm or eggs.
Hemochromatosis
Hemochromatosis is a genetic disorder caused by a mutation in a gene that controls how your body absorbs iron. This condition can cause the body to store more iron than it needs, which damages organs such as the liver and heart. It is most common among people of Northern European ancestry. Women are more likely to develop the condition than men.
The symptoms of Hemochromatosis include abdominal pain, weakness, and unexplained weight loss. The condition is usually diagnosed after the person has had several blood tests and a physical exam. Some doctors recommend a liver biopsy to determine if too much iron is stored in the liver. During a liver biopsy, the doctor removes a small piece of the liver and sends it to a lab for testing. The test can also show if a person has the HFE gene mutation that causes hereditary hemochromatosis.
Genetic disorders can affect any part of the body, including the skin and internal organs. Some are inherited from parents, while others occur because of changes in DNA that happen randomly during the course of a person’s life. These changes can be triggered by environmental factors such as smoking, alcohol, and exposure to sunlight or certain chemicals.
Some genetic disorders are inherited in an autosomal dominant fashion, which means one mutated copy of the gene is enough to cause the disease. Other genetic disorders are inherited in an autosomal recessive manner, which means that two mutated genes must be present to cause the disease. A third type of genetic disease, called transfusion-related hemochromatosis, is caused by a change in the HFE gene that happens after someone receives multiple blood transfusions.
Cystic fibrosis
Cystic fibrosis is an inherited disease that affects the respiratory and digestive systems. It causes thick, sticky fluids to build up in the lungs and other organs. These fluids can prevent them from working properly, causing chronic lung infections and difficulty breathing. They can also trap bacteria and lead to malnutrition. The symptoms of cystic fibrosis vary widely among people with this condition. Some people have a severe version of the disease, while others have only mild symptoms.
The genetic mutations that cause cystic fibrosis change the structure of cells in the body that produce mucus, sweat, and digestive juices. These fluids become thick and sticky, causing damage to the lungs and other organs. The disorder is inherited through autosomal dominant or recessive inheritance. This means that a person must inherit a defective gene from both parents to develop it.
Symptoms of cystic fibrosis include chronic coughing, wheezing, and difficulty breathing. In advanced cases, the disease can lead to lung failure and malnutrition. The condition is also associated with reproductive problems in men and decreased fertility in women.
Cystic fibrosis can be diagnosed with blood tests and other medical exams. Treatment is based on managing symptoms and improving quality of life. Doctors prescribe drugs such as antibiotics, bronchodilators, mucolytic agents, and digestive enzymes. They may also recommend a special diet to help you absorb nutrients. People with CF may also need to undergo lung or chest transplants. Treatment is ongoing, and scientists are working toward a cure.
Aneuploidy
Aneuploidy is when a cell has an abnormal number of chromosomes. This can occur in cells that divide during meiosis (the process of producing sperm and eggs) or mitosis (the process of creating new cells in the body). Errors in these processes increase the likelihood of chromosomes mis-segregating, resulting in aneuploidy.
Chromosomes contain genes, which are instructions for making proteins. They are located in the middle of the cell and are held together by a structure called kinetochores. These kinetochores are attached to the centromeric centromeres of each chromosome. They also have attachment points for microtubules that are oriented toward one pole of the spindle. This ensures that sister chromatids separate correctly at anaphase and that the spindle microtubules are aligned with each other. In the event of an error, the attachments between kinetochores and microtubules are disrupted, and the chromosomes do not segregate correctly during mitosis. This is called structural aneuploidy.
In most cases, aneuploidy is caused by errors in meiosis or mitosis. However, it can also be caused by genetic disorders and some medications. Aneuploidy can result in several conditions, including Down and Klinefelter. It can also cause heart defects, developmental delays, and learning problems.
Aneuploidy can be detected with a simple test called chorionic villus sampling (CVS). It is performed in the first trimester of pregnancy, between 10 and 13 weeks. It involves taking a sample of cells from the placenta. The healthcare provider will then check the cells for aneuploidy and other genetic conditions. The results will be available in about two weeks. If the result is positive, the healthcare provider will refer the mother to a genetic counselor for further testing and treatment options.
Chromosomal abnormalities
Chromosomal abnormalities involve a mutation in the chromosomes, which contain your genes. These genetic disorders can cause severe symptoms such as muscular dystrophy, and some can result in death, though they may not be immediately fatal. Many of these diseases have a variety of treatment options, such as medication and physical therapy. These treatments can slow the progression of the disease and help maintain quality of life. Symptoms of these diseases may not be present until later in life, and patients can sometimes live with them for a lifetime.
Most of these genetic disorders are caused by an error that occurs during cell division in the development of eggs and sperm. This error is called nondisjunction, and it can result in the reproductive cells of a baby receiving an extra or missing chromosome. These atypical reproductive cells contribute to the DNA of the baby and may lead to chromosomal conditions like Down syndrome or Turner syndrome.
These chromosomal conditions can affect either the autosomal chromosomes or the sex chromosomes, which consist of two X chromosomes for females and one Y chromosome for males. All of the genetic information in a human is stored in these 46 chromosomes, and they make up around two meters of DNA. The most common chromosomal anomalies are those that affect the autosomal chromosomes, with fewer affecting the sex chromosomes.
These chromosomal abnormalities are classified as numerical or structural, with the former referring to any deviation from the diploid number of chromosomes in a human. Numerical chromosomal abnormalities are those in which a whole chromosome is either missing from or added to the normal pair, while structural abnormalities refer to the structure of individual chromosomes and can include deletions, duplications, inversions, translocations, and ring chromosomes. The most well-known chromosomal disorder is aneuploidy, which results in an extra chromosome. This condition is most commonly associated with Down syndrome and Klinefelter syndrome.
