Asyim,

I don't have the actual lab results in front of me to double-check my numbers, but are you sure the units of measure are the same?  My lab uses ng/mL but I think this is unusual.  Could the units Turkey uses be nmol/mL or something like that?  It is very difficult to compare numbers from different laboratories since they use different methods and different units of measure.

I understand from your post your son's newborn screen level was 7.5 and based on this result it was determined that he might have CAH.  Then, later testing in London showed that the 7.5 was a "false-positive" and that he does not have CAH.  I am not sure if newborn screening cut-off levels should be compared to the numbers I showed.  You might want to check the Texas Department of Health's website and see what numbers they use for their newborn screening cutoff levels.  Then you could compare that to what Turkey is doing (making sure that you are using comparable units of measure). 

If Turkey's newborn screening cut-off was too low, then they would have a lot of false-positives, which would be very expensive.  So I am sure the people at the university in Ankara know what they are doing.  I am confident that they understand the numbers better than I do!