Estimated incidence of sickle-cell disease in Aruba and St. Maarten suggests cost-effectiveness of a universal screening programme for St. Maarten.

OBJECTIVE: To estimate the incidence of Sickle-Cell Disease (SCD) in Aruba and St. Maarten and to determine whether universal screening would be cost-effective according to United Kingdom criteria. METHODS: Consecutive cord blood samples were collected in Aruba and the Dutch part of St. Maarten during 3 and 4 months, respectively. Samples were subjected to High Performance Liquid Chromatography (HPLC) screening of haemoglobin variants. RESULTS: Of the 368 samples (87.6% of all registered births) collected in Aruba, 10 (2.72%; CI 1.3, 4.9%) tested heterozygous for the Sickle-cell gene (HbAS) and 7 (1.90%; CI 0.8, 3.9%) for the haemoglobin C gene (HbAC). Of the 193 samples (83.5%) collected in St. Maarten, 14 (7.25%; CI 4.0, 11.9%) contained HbAS and 10 (5.18%; CI 2.5, 9.3%) HbAC. Hardy-Weinberg equilibrium predicted an incidence of 2.65% for HbAS and 1.86% for HbAC in Aruba and 6.80% for HbAS and 4.86% for HbAC in St. Maarten. These figures imply a newborn rate of about 2 SCD patients per 3 years in Aruba and 2 SCD patients per year in St. Maarten. CONCLUSIONS: Universal screening of newborns for SCD seems cost-effective for St. Maarten.

á-N-terminal glycated haemoglobins (HbX) in subjects with common haemoglobinopathies: relation with fructosamine and mean erythrocyte age - abstract

á-N-terminal glycated haemoglobins (HbX, by HPLC), serum fructosamine and erythrocyte polyamines were determined in non-diabetic adults with HbAA, HbAC, HbAS, HbCC, HbSC, HbSS and Hb/HPFH. The groups did not differ in fructosamine. Mean (95 percent confidence limits) percentage HbX were: 4.4 (range 4.1 - 4.8) for HbA in HbAA, 4.3 (range 3.9 - 4.8) for HbA in HbA in HbAA, 4.3 (range 3.9 - 4.8) for HbA in HbAC, 4.1 (range 3.6 - 4.6) for HbC in HbAC, 4.4 (range 4.0 - 4.7) for HbA in HbAS, 2.6 (range: 2.3 - 3.8) for HbC in HbCC, 2.0 (range 1.5 - 2.4) for HbS in HbSC, 0.9 (range: 06. - 1.3) for HbS in HbSS, and 1.3 (range: 0.8 - 2.4) for HbS in HbS/HPFH. Considering all data, there was a non-linear inverse relation between HbX and erythrocyte polyamines, indicating that percentage HbX decreases with decreasing mean RBC-age. It is concluded that HbX in subjects with heterozygous haemoglobinopathies is to be expressed as percentage HbX + HbC, not total haemoglobin. Interpretation of HbX in subjects with decreased RBC half-life is difficult. Fructosamine seems a suitable alternative (AU)

Beta-N-terminal glycohemoglobins in subjects with common hemoglobinopathies: relation with fructosamine and mean erythrocyte age.

Amounts of beta-N-terminal glycohemoglobins (HbX1c), serum fructosamine, and erythrocyte polyamines were determined in nondiabetic adults with HbAA, HbAC, HbAS, HbCC, HbSC, HbSS, and HbS/hereditary persistent HbF (HPFH). The groups did not differ in fructosamine concentrations. Mean (95% confidence limits) HbX1c percentages were: 4.4 (4.1-4.8) for HbA1c in HbAA, 4.3 (3.9-4.8) for HbA1c in HbAC, 4.1 (3.6-4.6) for HbC1c in HbAC, 4.4 (4.0-4.7) for HbA1c in HbAS, 2.6 (range: 2.3-3.8) for HbC1c in HbCC, 2.0 (1.5-2.4) for HbS1c in HbSC, 0.9 (0.6-1.3) for HbS1c in HbSS, and 1.3 (range: 0.8-2.4) for HbS1c in HbS/HPFH. There was a nonlinear inverse relation between HbX1c and erythrocyte polyamines, indicating that HbX1c percentage decreases with decreasing mean erythrocyte age. We conclude that amounts of HbX1c in subjects with heterozygous hemoglobinopathies should be expressed as a percentage of HbX0 + HbX1c, not total hemoglobin. Interpretation of HbX1c in subjects with a decreased erythrocyte half-life is difficult; measurement of fructosamine seems a suitable alternative.