Genetic diseases recessive genes

Cystic fibrosis is an autosomal, recessive genetic disease with an increase of 1/2000 in Caucasian births. It is the most common lethal, inherited disease among Caucasians 50% of the victims of this disease survive to 16 years and only 2% to age 35. Heterozygotes carrying the CF gene make up about 5% of the United States population but do not express the disease. 

Hereditary fructose intolerance is a rare recessive genetic disease that is most commonly caused by a mutation in exon 5 of the aldolase B gene. The mutation fortuitously creates a new Ahall recognition sequence. To test for the mutation, DNA was extracted from a wife, husband, and their two children. Jack and Jill. The DNA for exon 5 of the aldolase B gene was amplified by polymerase chain reaction (PCR), treated with Ahall, subjected to electrophoresis on an agarose gel, and stained with a dye that binds to DNA. 

The genetic abnormalities in Down syndrome involve dominant genes. Hundreds of abnormal human traits are related to dominant inheritance, whereas an equal number are recessive. An example of the latter is sickle cell anemia, a disease in which an abnormal recessive gene is inherited from each parent. If one parent does not have the recessive gene, the child will carry the sickle-cell trait, but not symptoms and signs of the disease. 

Genetic diseases are relatively rare, in part because most are caused by recessive genes that cause little trouble except in individuals who inherit two copies (Nesse and Williams, 1994). This is a very rare event because the recessive gene must come from both parents, and, if either of the parents is homozygous recessive, that parent will not likely have the same reproductive success as any parent with the dominant gene (Figure 5.3.5). 

Cystic fibrosis (CF) is a common form of an autosomal recessive genetic disease within the Caucasian population. The mutant gene lacks three base pairs (bp) in... 

Cystic fibrosis (CF) is a genetic disease caused by mutations to the gene coding the cystic fibrosis transmembrane conductance regulator (CFTR) protein in many epithelial cells and blood cells. It is the most common autosomal recessive disorder in Caucasians and affects approximately 28,000 patients in the United States and approximately 36,000 patients in Europe. An estimated 70,000 people worldwide have CF. The life expectancy of patients with CF has risen steadily over the last 25 years, from a median predicted age of survival of 25 years in 1985 to 37 years in 2011. Since in the United States an orphan disease is defined as an disease afflicting fewer than 100,000 patients, CF is an orphan disease, and ivacaftor (Kalydeco, 1) is an orphan drug. The drug is also known as a personalized medicine because CF affects about only 70,000 people worldwide. 

This disease group is defined by renal cysts at the corticomedullary junction and classified into a recessive form (nephronophthisis) and dominant form (medullary cystic kidney disease) (OMIM 256100 and 174000). Nephronophthisis is genetically heterogeneous, four genes have been mapped and identified (NPHPl-4). Additional genes can be expected. 

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