The white blood cell DNA of 36 cord blood samples with Hb Bart's in the red blood cells was studied for alpha-globin gene deletions by hybridization of DNA fragments digested by the restriction endonucleases Eco RI, Hpa I, Bam HI, and Bgl II. All 16 DNA samples from cord blood with Hb Bart's below 3% and no other abnormal hemoglobin had one alpha-globin gene deletion (alpha thal2), except one which had two alpha-globin gene deletions (alpha thal1). Most of the alpha thal2 were of the rightward deletion alpha thal2 genotype. Two new types of alpha thal2 variation was found, probably due to a polymorphism somewhere in an area outside the alpha-globin gene. All 14 cases with Hb Bart's between 3.5% and 8.5% and no other abnormal hemoglobin had two alpha-globin gene deletions (alpha thal1), except one that did not have any alpha-globin gene deletion and one that had one alpha-globin gene deletion. Three DNA samples of cord blood with Hb Bart's accompanied by Hb CoSp did not have any alpha-globin gene deletion. Sixty-five DNA samples from cord blood without Hb Bart's or other abnormal hemoglobin had no alpha-globin gene deletions, except one that had one alpha-globin gene deletion (alpha thal2). Two of the 65 DNA samples were found to have triplicated alpha-globin gene loci.
To correlate Heidelberg Retina Tomograph (HRT) derived macular edema (DME) index with severity of diabetic retinopathy and systemic factors. A total of 300 diabetic patients were recruited for the study for each of them a value for the macular edema index was obtained using the HRT II. Patients' age, gender, duration and type of diabetes mellitus, latest HbA1c result and presence or absence of co-morbid factors (hypertension, ischemic heart disease, nephropathy) were recorded together with the stage of diabetic retinopathy. These were correlated with DME. Out of 300 patients, HRT defined macula edema was seen in 68 patients (22.6%). There is a wider and higher range (95% percentile) of macula edema index in the severe non proliferative diabetic retinopathy (NPDR) group. Independent samples t test showed significant difference between the severe NPDR group and no DR group (p<0.001), mild NPDR group (p<0.05) and moderate NPDR group (p<0.05). A higher macula edema index was also found to have a low degree of correlation with more advanced stages of retinopathy (r=0.310; p<0.001). Also nephropathy showed a strong and significant correlation with DME. Hypertension had moderately significant correlation with DME. This study found no correlation between ischemic heart disease and DME. HRT derived scanning laser edema index is a reliable objective tool to evaluate diabetic retinopathy and systemic risk factors.