الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
There have been few attempts to screen the prevalence of Thalassemia trait in Egypt, partly because of lack of reliable inexpensive screening methods.
In our study several schemata suggested for mass screening of Thalassemia trait were applied,starting with picking up cases with microcytosis directly measured by the electronic cell counter.
All microcytic cases were then subjected to Hb A2 estimation. If the values were 4.5% or more, the
case was considered Thalassemia trait (Pearson et al,
1973) .
Further support for the diagnosis was obtained through other methods and formulae which also helped in finding out which is most reliable, simple, and inexpensive one. Out of 450 individuals examined the
following groups were studied :-
40 normal subject with normal haemoglobin value and normal mean corpuscular volume ( group I ) .
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40 subject with normal haemoglobin value and reduced MCV - otherwise absolutely normal ( group II ) .
25 cases with both reduced Hb & MCV i.e. anaemia with microcytosis & showing no specific clinical finding of any disease (group III ) .
The data obtained through electronic counter (Coulter-Model S) namely Hb, red cell count, haematocrit, MCV& MCH were used in applying the different formulae &
ratios vis
Hamilton & Davidson (1973) : H & D Shine & Lal (1977) : Sh.L.
Strivasta & Bevington (1973) : R/S England & Frazer (1973) : D.F. Mentzer (1973) : R/M .
Also examination of haemoglobin F & A2, as well as tests for Hb H were done for all cases. The Glycerol Lysistive GLT50 was used as a differentiating test and screening for Thalassemia carriers. (Gottfried &
Robertson 1974).
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The results of the different tests, ratios and functions, for the three groups were tabulated, statistically analysed and compared. Also correl-ative studies for the different values were done and the corresponding graphs and linear regressions were established.
The same kind of study was repeated for two sub-groups obtained from groups II & III by selecting cases with elevated Hb A2 (4.5% or more) strongly supporting their Thalassemic nature.
The summary of the results obtained are as follows :
The number of Thalassemia traits ( as evidenced by elevated Hb A2) was 32 among the 450 individuals i.e. 7.1% .
The Glycerol Lysis time was prolonged in 95.5% of cases of group II thus giving the highest positive screening value for Thalassemia carriers compared with the other formulae and ratios which was 72.7% in both DF and the Sh.L. and only about 50% in
R/M & S/S values.
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The values for these indices are contrasting signi-ficantly with either those for normals (group I) & anaemics (group III), giving a very strong support for their value in screening purposes.
The relation between the red cell volume and the MCH as given by the H&D ratio was also found highly significant in differentiating the compensated microcytic cases (group II) from the other two. (Normals and anaemics) .
The following points are concluded :
1.Electronic counting of blood indices must be popularized in every respect.
2.Values obtained must be further processed to calculate the different formulae and functions useful in screening Thalassemic traits.
3.Using the Glycerol Lysis time incases of micro-cytosis in general and in compensated type in particular - for its high value in screening Thalassemia carriers.
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4. The incidence of carriers for the Thalassemic genes is appreciably high and deserves more condensed studies by the proposed means in a locality like
Egypt. The study bears its vital importance in such situation where anaemias are so frequent & with divers mechanisms such as deficiency in iron, mutritiorial factors enzymopathies.