Genetic diseases reverse genetics

Reverse genetics has been applied to diseases such as Duchenne muscular dystrophy and cystic fibrosis, in which the responsible enzymes are unknown and the disease results from a significant deletion. By combining RFLP analysis with cytogenetics, it has been possible to increasingly narrow the location of the defective genes to small regions on the affected chromosomes. 

Genetic deficiency of fructokinase is benign and often detected incidentally when the urine is checked for glucose with a dipstick. Fructose 1-phosphate aldolase deficiency is a severe disease because of accumulation of fructose 1-phosphate in the liver and renal proximal tubules. Table 1-12-4 compares the two conditions. Symptoms are reversed after removing fructose and sucrose from the diet. 

Although chelation is not helpful for Alzheimer s disease patients, it is the key to treating patients with dementia due to Wilson s disease. Wilson s disease is a genetically inherited disorder that usually strikes before age 30. The disease causes toxic levels of copper to accumulate in the liver, brain, eyes, and kidney. Untreated, Wilson s disease leads to tremors, cirrhosis, depression, psychosis, dementia, and ultimately death. Chelation with penicillamine (Cuprimine) can stop and even reverse the accumulation of copper. 

The genetic material in a retrovirus is RNA not DNA. The best known retrovirus is the human immunodeficiency virus (HIV) which infects lymphocytes and hence interferes with the immune system, giving rise to the disease AIDS. Once the virus infects its host, it converts its RNA into DNA by an enzyme known as reverse transcriptase and the DNA is then inserted into the genome of the host cell (in this case the lymphocyte) ... 

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