The aim of this prospective study was to evaluate the long-term efficacy and safety of hydroxyurea (HU) in patients with sickle cell disease (SCD). Thirty-four patients with sickle cell anemia (hemoglobin S [HbS]/HbS), 131 with HbS/␤ 0 -thal, and 165 with HbS/␤ ؉ -thal participated in this trial. HU was administered to 131 patients, whereas 199 patients were conventionally treated. The median follow-up period was 8 years for HU patients and 5 years for non-HU patients. HU produced a dramatic reduction in the frequency of severe painful crises, transfusion requirements, hospital admissions, and incidence of acute chest syndrome. The probability of 10-year survival was 86% and 65% for HU and non-HU patients, respectively (P ‫؍‬ .001), although HU patients had more severe forms of SCD. The 10-year probability of survival for HbS/ HbS, HbS/␤ 0 -thal, and HbS/IVSI-110 patients was 100%, 87%, and 82%, respectively, for HU patients and 10%, 54%, and 66%, for non-HU patients. The multivariate analysis showed that fetal hemoglobin values at baseline and percentage change of lactate dehydrogenase between baseline and 6 months were independently predicted for survival in the HU group. These results highlight the beneficial effect of HU, which seems to modify the natural history of SCD and raise the issue of expanding its use in all SCD patients. (Blood.

The prenatal diagnosis of cystic fibrosis is now routinely performed by using two probes tightly linked to the CF locus (XV2C and KM19). These probes have been shown to exhibit a strong linkage disequilibrium with the CF locus. Our data (103 families) have been pooled with other French data (237 families). They are consistent with the hypothesis of a unique ancestral mutation initially associated with a B (D1E2) restriction fragment length polymorphism (RFLP) haplotype, subsequently reassociated by cross-over with A, C or D haplotypes. Assuming such an hypothesis, the mutation is supposed to be 3000-6000 years old, depending on generation length and the true recombination ratio between the KM19 and CF loci. Up-to-date Spanish, Danish and Greek data are reported together with other previously published population data in order to discuss the geographic origin and age of the mutation in Europe. The action of selection in terms of heterozygote advantage and distorsion of segregation is discussed.

The N1303K mutation was identified in the second nucleotide binding fold of the cystic fibrosis (CF) gene last year. We have gathered data from laboratories throughout Europe and the United States of America in order to estimate its frequency and to attempt to characterise the clinical manifestations of this mutation. N1303K, identified on 216 of nearly 15,000 CF chromosomes tested, accounts for 1.5% of all CF chromosomes. The frequency of the N1303K allele varies significantly between countries and ethnic groups, being more common in Southern than in Northern Europe. This variation is independent of the delta F508 allele. It was not found on UK Asian, American Black or Australian chromosomes. N1303K is associated with four different linked marker haplotypes for the polymorphic markers XV-2c, KM.19 and pMP6d-9. Ten patients are homozygous for this mutation, whereas 106 of the remainder carry one of 12 known CF mutations in the other CF allele. We classify N1303K as a "severe" mutation with respect to the pancreas, but can find no correlation between this mutation, in either the homozygous or heterozygous state, and the severity of lung disease.

The presence of two different mutations carried by the same CF allele has been demonstrated in four out of 44 Bulgarian CF patients during a systematic search of the entire coding sequence of the CFTR gene. Two of the double mutant alleles include one nonsense and one missense mutation and although the nonsense mutation can be considered to be the main defect, the amino acid substitutions are good candidates for disease-causing mutations as well. One double mutant carries two missense mutations whose contribution to the CF phenotype is difficult to evaluate. The findings suggest that double mutant alleles may be more common than expected and could account for some of the problems in phenotype-genotype correlations. Such alleles may have important implications for molecular diagnosis and genetic counselling.

The decline of EPF in patients with CF appears more frequently during the first months and years of life. However, late PS to pancreatic-insufficient (PI) conversion is also possible. The appearance of maldigestion is preceded by the decrease of fecal E1 concentration. Thus, the fecal E1 test is a helpful screening tool for the longitudinal assessment of declining EPF in PS patients with CF to demonstrate pancreatic deterioration. In suspected patients, fecal fat excretion should be assessed.

We have analysed five Southern European populations (Albanian, Greek, Italian, Spanish and Yugoslavian) for 14 cystic fibrosis (CF) mutations. The most frequent mutations, apart from delta F508, were G542X (6.04%), R1162X (3.61%) and N1303K (3.24%). Each of the other analysed mutations were present at a frequency of less than 1% (R347P, R334W, S549RA, S549I, G551D, R553X and W1282X), and four mutations (D110H, delta I507, S549RT, and S1255X) were not found in this sample. The data presented here allows the use of mutation analysis in 69.5% of Spanish, 58% of Greek, and 56.5% of Italian CF cases.

Although several complications can occur during a pregnancy in TI women, the careful and frequent monitoring by both hamatologists and obstetricians can lead to successful deliveries.

No abstract