The gamma globin chain heterogeneity of the Sardinian newborn baby.

The hemoglobin of 2048 newborn babies from Sardinia was analyzed by isoelectric focusing and polyacrylamide gel electrophoresis in order to determine the level of Hb F-Sardinia (with A gamma T) and the G gamma chain. Hb F-Sardinia values of 15.5 +/- 2.6% were present in the A gamma T heterozygote whereas 30.7 +/- 5.2% were present in the homozygote. The A gamma T gene frequency was 0.17. Most of the babies tested showed the normal G gamma level either in the absence of the A gamma T anomaly (69.6 +/- 4.1%), or in the presence of the anomaly in both the heterozygous state (70.9 +/- 4.8%) and the homozygous state (71.1 +/- 3.4%). Similar values were shown in nine homozygotes for beta-thalassemia discovered during the screening. Nine newborn babies (0.44%) showed particularly low G gamma levels (38.3 +/- 6.8%) whereas 18 newborn babies showed high G gamma levels (83.9 +/- 2.6%). The frequencies of the anomalies (0.0022 for the low G gamma and 0.0044 for the high G gamma) were the lowest observed in Caucasian and other ethnic groups. Data suggest the presence of abnormal gamma globin gene arrangements in the Sardinian population.