Genetic disorders are conditions that are caused by changes in a person's genes or chromosomes. These changes can be inherited from a parent or can occur spontaneously. Some genetic disorders are caused by a single gene mutation, while others are caused by a combination of gene mutations. Some of the most common genetic disorders include cystic fibrosis, Huntington's disease, cleft lip and cleft palate, albinism, Apert syndrome, and congenital adrenal hyperplasia.
Cystic fibrosis is an inherited disorder that affects the lungs and digestive system. It is caused by a mutation in the CFTR gene, which is responsible for producing a protein that helps regulate the movement of salt and water in and out of cells. People with cystic fibrosis have thick, sticky mucus that builds up in their lungs and digestive tract, leading to breathing difficulties and digestive problems. Huntington's disease is an inherited disorder that affects the brain and nervous system.
It is caused by a mutation in the HTT gene, which is responsible for producing a protein called huntingtin. People with Huntington's disease experience progressive deterioration of their mental and physical abilities. Cleft lip and cleft palate are birth defects that affect the face and mouth. They are caused by a combination of genetic and environmental factors.
People with cleft lip and cleft palate have an opening in their upper lip or roof of their mouth that can cause difficulty eating, speaking, and breathing. Albinism is a group of genetic conditions that affect the production of melanin, the pigment that gives color to skin, hair, and eyes. People with albinism have no color or have very little color in their hair, skin, and eyes, so sun protection is vital. Apert syndrome is a rare condition that causes an abnormal skull shape and fusion of the fingers and toes.
Surgery and other treatments can help development. Congenital adrenal hyperplasia affects hormones. People with this condition will have health problems, but they may continue to enjoy a normal lifestyle. Genetic disorders can also be complex, multifactorial, or polygenic, meaning that they are likely associated with the effects of multiple genes in combination with lifestyles and environmental factors. Multifactorial disorders include heart disease and diabetes. The opposite of an hereditary disease is an acquired disease.
Most cancers, although they involve genetic mutations in a small proportion of the body's cells, are acquired diseases. However, some cancer syndromes, such as BRCA mutations, are inherited genetic disorders. Complex disorders are also difficult to study and treat because the specific factors that cause most of these disorders have not yet been identified. Studies that aim to identify the cause of complex disorders can use several methodological approaches to determine associations between genotype and phenotype. One method, the approach that prioritizes the genotype, begins by identifying genetic variants in patients and then determining the associated clinical manifestations. This is contrary to the more traditional approach, which prioritizes the phenotype and can identify causal factors that were previously hidden by clinical heterogeneity, penetration and expressiveness. There are more than 6,000 known genetic disorders and new genetic disorders are constantly being described in the medical literature.
A woman with an X-linked dominant disorder has a 50% chance of having an affected fetus in each pregnancy. If there is a family history, DNA testing for genetic disorders can be an important part of starting a family. Genetic conditions are often called hereditary because they can be passed from parent to child. While polygenic disorders are the most common type of genetic disorder, the term is mostly used when talking about disorders with a single genetic cause either in a gene or in a chromosome. Because of the wide range of genetic disorders that are known, diagnosis is very varied and depends on the disorder. Genetic disorders can range from a defect in a single-base mutation in the DNA of a gene to chromosomal abnormalities that involve the deletion or addition of complete chromosomes or sets of chromosomes. Most genetic disorders are diagnosed before birth at birth or during early childhood; however some such as Huntington's disease may go undetected until the patient reaches adulthood. Not all genetic disorders directly cause death; however there is no known cure for genetic disorders. To understand the causes of genetic disorders it's helpful to learn more about how genes and DNA work. Only a few disorders have this pattern of inheritance; one good example is X-linked hypophosphatemic rickets.