Diagnosis of hemochromatosis in young subjects: Predictive accuracy of biochemical screening tests

1984 ◽  
Vol 87 (3) ◽  
pp. 628-633 ◽  
Author(s):  
Mark L. Bassett ◽  
June W. Halliday ◽  
Robyn A. Ferris ◽  
Lawrie W. Powell
1982 ◽  
Vol 21 (03) ◽  
pp. 149-153
Author(s):  
B. C. K. Choi

This paper proposes a new pair of indices, the »predictive powers«, for measuring the predictive accuracy (predictivity) of screening tests.Sensitivity and specificity are indices for measuring the validity of a test. They give the probability of a certain test result given a substance of known condition (a carcinogen or a non-carcinogen). They do not describe the predictive accuracy of a test, which is the probability of a certain condition (a carcinogen or a non-carcinogen) given a known test result. Predictive values are unsuitable measures for characterizing a test since they are seriously affected by the prevalence of carcinogens. However, the predictive powers do not have this limitation and are shown to be useful indices for the purpose of rating the predictive accuracies of various screening tests.


Genes ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1821
Author(s):  
Noraesah Mahmud ◽  
Massimo Maffei ◽  
Massimo Mogni ◽  
Gian Luca Forni ◽  
Valeria Maria Pinto ◽  
...  

Background: Hemoglobin A (Hb A) (α2β2) in the normal adult subject constitutes 96–98% of hemoglobin, and Hb F is normally less than 1%, while for hemoglobin A2 (Hb A2) (α2δ2), the normal reference values are between 2.0 and 3.3%. It is important to evaluate the presence of possible delta gene mutations in a population at high risk for globin gene defects in order to correctly diagnose the β-thalassemia carrier. Methods: The most used methods for the quantification of Hb A2 are based on automated high performance liquid chromatography (HPLC) or capillary electrophoresis (CE). In particular Hb analyses were performed by HPLC on three dedicated devices. DNA analyses were performed according to local standard protocols. Results: Here, we described eight new δ-globin gene variants discovered and characterized in some laboratories in Northern Italy in recent years. These new variants were added to the many already known Hb A2 variants that were found with an estimated frequency of about 1–2% during the screening tests in our laboratories. Conclusions: The knowledge recognition of the delta variant on Hb analysis and accurate molecular characterization is crucial to provide an accurate definitive thalassemia diagnosis, particularly in young subjects who would like to ask for a prenatal diagnosis or preimplantation genetic diagnosis.


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