The purpose of this study was to examine the frequency of
alpha-thalassemia in the population of Cyprus using cord blood samples. The levels of
Hb Bart's were compared with the hematological indices and the results correlated with the presence of
alpha-thalassemia mutations. The protocols for the polymerase chain reaction detection of the six most common
alpha-globin mutations encountered in Cyprus were optimized, and the frequency of each mutation was determined through the screening of 495 random cord blood samples. The total allele frequency for the mutations examined was 10.6%, of which 1% is due to the triplication of the
alpha-globin genes. The -alpha(3.7 kb) deletion accounts for 72.8% of all detectable mutations, while the--MED-I and -(alpha)-20.5 kb mutations account for 7.8%. The level of
Hb Bart's and the MCV and MCH values in cord blood samples were found to correlate closely with the severity of
alpha-thalassemia, although the -alpha(3.7 kb) deletion and perhaps other mild
alpha-thalassemia mutations may not give detectable
Hb Bart's levels. A reasonably accurate estimate of the
alpha-thalassemia carrier frequency may be obtained from cord blood studies if
Hb Bart's estimates are combined with hematological indices. When molecular methods are added, these give the best way to use cord bloods to survey populations for
alpha-thalassemia.