Genetic diseases occur because of abnormal genes or chromosomes. Causes of genetic diseases include mutated genes, chromosome duplication, missing chromosomes and a portion of a chromosome erroneously attaching to another chromosome. Some genetic diseases result from random mutations. Other genetic diseases are inherited and passed down from one generation to the next.
Cystic Fibrosis
The Cystic Fibrosis Foundation reports that cystic fibrosis affects about 30,000 children and adults in the United States. A defective gene causes the body to produce a thick, sticky mucous that clogs the lungs and obstructs the natural enzyme production of the pancreas that helps with food absorption.
Fragile X
Fragile X, a group of genetic conditions, affects families differently. The Fragile X syndrome causes inherited mental disabilities. Fragile X-associated tremor/ataxia syndrome affects men, and Fragile X-associated primary ovarian insufficiency affects women.
Hemophilia
Hemophilia A and hemophilia B, genetic bleeding disorders, are the results of mutations of the F8 and F9 genes. Both types occur more in men than women. Genetics Home Reference reports that of the two types of hemophilia, hemophilia A is more common.
Marfan Syndrome
Marfan syndrome is a genetic disease caused by a mutated gene responsible for making a protein that is part of the connective tissue. The two ways to get Marfan syndrome are through inheritance and through spontaneous gene mutation. Body systems affected include the skeletal, cardiovascular and ocular.
Neurofibromatosis
Neurofibromatosis (NF), a nervous system disorder, causes tumors to form on nerves. Neurofibromatosis, Inc. reports NF as one of the most common genetic disorders in America, affecting one of every 3,000 to 4,000 births. About one-half of neurofibromatosis cases are inherited and the other half result from spontaneous genetic mutation.
Sickle Cell Disease
Sickle cell disease, an inherited genetic disease, is a blood disorder affecting red blood cells. Of the several types of sickle cell disease, the most common are sickle cell anemia, sickle-hemoglobin C disease, sickle beta-plus thalassemia and sickle beta-zero thalassemia.
Prader-Willi Syndrome
Prader-Willi Syndrome is a complex genetic condition caused randomly during the process of early embryonic development. Symptoms in early life include delayed development and poor growth. Adult symptoms include obesity and type 2 diabetes.
Crouzon's Syndrome
The International Craniofacial Institute says Crouzon's syndrome is a rare deformity affecting only one out of 10,000 infants born every day in the United States. A gene alteration usually not associated with the parents causes Crouzon's syndrome. Most children with Crouzon's experience no mental deficits.
Canavan Syndrome
Canavan syndrome, a common cerebral degenerative genetic disease in newborns, causes slowly progressing brain atrophy. Mutations in the gene for the enzyme aspartoacylase cause Canavan syndrome. Life expectancy is poor, with a maximum of about 4 years old. Genetic testing for this gene is available.
Tay-Sachs Disease
Tay-Sachs, an inherited disease caused by the lack of Hexosaminidase A enzymes, is most common among Ashkenazi Jews. The risk for this disease, which affects a baby's hearing, sight, mental development and mobility, is one out of 27 Ashkenazi Jews, compared to one in 250 people in the general population.
