Genetic testing hemophilia

Direct tests have been applied to sickle-cell disease, thalassemia, and hemophilia A and have documented this great genetic diversity. About 100 defective gene sites have been identified for thalassemia, and there may be more than 1000 associated with the factor VIII gene. 

Thee future prospects for naked DNA gene therapy include clinical trials for genetic diseases (e.g., Duchenne muscular dystrophy, ischemia, hemophilia), which would be initiated in the next few years, and tail vein injections in rodents, which will become a widely used technique for rapidly testing expression vectors/gene therapy approaches (101). 

American and British scientists unveiled a technique for testing embiyos in vitro for genetic abnormalities such as cystic fibrosis and hemophilia. 

Recent advances in molecular genetic analysis have greatly improved the accuracy of carrier status evaluation. Thus female relatives of patients with hemophilia who are at risk of being carriers for the disorder should be tested. Additionally, the appropriate factor level should be measured in female carriers to identify those with levels less than 0.3 units/mL (30%) who might themselves be at risk of bleeding. 

The penetrance of genetic factors is another parameter in complex diseases. If the penetrance of these factors is indeed very low, as studies to date indicate, new approaches wiU be necessary to detect them. It seems already dear that the relative genetic risk of single variants is very small in complex diseases. Therefore, predictions can only provide risk probabilities but not risk certainties. On the other hand, in cases of low complexity and single nucleotide polymorphisms (SNPs) with high penetrance, the predictive power of tests reaches close to certainty as shown for hemophilia. 

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