Analyse comparée du coût des techniques cytogénétiques et de biologie moléculaire dans le diagnostic de la maladie de l'X fragile

Abstract

International audienceMental retardation is sometimes due to chromosomal abnormalities. Most frequent illnesses are Down syndrome and Fragile X syndrome. Using a cost analysis, we try to see what diagnosis method is the most relevant to find chromosomic causes for mental retardation in an institutionalized male population. Two techniques are compared: cytogenetic technique and molecular biology technique. Four diagnostic strategies are identified. They all have the same effectiveness, but, costs vary. Results depend on prevalence rates in the epidemiologic literature on Fragile X syndrome and other chromosomic abnormalities. The least-cost diagnostic strategy is molecular biology then constitutional karyotype in case of a negative result. This strategy costs about 600 FF1991 less compared with Fragile X karyotype and about 120 FF1991 less than when molecular biology is done in second, for fixed prevalence rates (i.e. Fragile X prevalence rate between 4.5 and 10% and other abnormalities between 2.2 and 25%). Fragile X karyotype strategy has the highest cost whatever the prevalence rates. Those results are discussed when introducing female population and delay to test results for prenatal diagnosis