Newborn screening for sickle cell disease: effect on mortality

Newborn screening for sickle cell disease has been recommended as a method of decreasing patient mortality. However, its effectiveness in accomplishing this has not been reliably measured. To help determine the effectiveness, 10 years of experience in newborn screening have been summarized. The effects of early patient enrollment in a comprehensive treatment program on long-term morbidity and mortality are reported. From 1975 to 1985, 84,663 newborns were screened regardless of race or ethnic background. Bart's hemoglobin was present in 5%, hemoglobin AS in 2.6%, and hemoglobin AC in 0.75%. Excluding Bart's, approximately 3.6% of all newborns were carriers for hemoglobinopathy. Sickle cell disease occurred in 1:951 births (58 hemoglobin SS, 25 hemoglobin FSC, three hemoglobin S-beta +-thalassemia, and three hemoglobin S-beta O-thalassemia). In addition, one in every 4,233 newborns had a clinically significant thalassemia syndrome (eight hemoglobin FE, ten hemoglobin F only, two hemoglobin H). Compared with other newborn screening programs in California, (congenital hypothyroidism, 1:3,849; phenylketonuria 1:22,474, galactosemia 1:74,103), hemoglobinopathies are the most prevalent congenital disease. Eighty-one newborns with sickle cell disease were followed for 7.2 years. Patients experienced 513 hospitalizations, including 13 episodes of sepsis with or without meningitis and ten acute sequestration crises. The overall mortality rate for patients with sickle cell anemia diagnosed in the newborn period was 1.8%. In comparison, the clinical course of 64 patients with sickle cell anemia diagnosed after 3 months of age and followed for an average of 9.4 years was analyzed. Five of these patients died. In two of these, sickle cell anemia was diagnosed at the time of the death.(ABSTRACT TRUNCATED AT 250 WORDS)     

Growing up with sickle cell disease: a pilot study of a transition program for adolescents with sickle cell disease

We implemented the Duke Sickle Cell Disease (SCD) Transition Program for adolescents with SCD and investigated the knowledge about SCD; concerns and emotions about transitioning; and the initial impact of the Transition Program. Thirty-three adolescents participated in the initial study. Gaps in knowledge included ethnicities affected by SCD and inheritance of SCD. Adolescents were primarily concerned about transferring to a new medical team. There was a mix of both positive and negative emotions that varied over time. Overall, we have identified educational gaps and concerns and emotions about transitioning, which we will address through the Duke SCD Transition Program.     

Hematopoietic cell transplantation: a curative option for sickle cell disease

Sickle cell disease is associated with considerable morbidity and premature mortality. Hematopoietic cell transplantation offers the possibility of cure and is associated with excellent results in pediatric patients receiving stem cell transplantation from a matched sibling donor. Reduced intensity conditioning regimen have the potential to further reduce regimen related morbidity and mortality. Improved understanding of the natural history of complications such as stroke and pulmonary hypertension, effects of treatments, such as hydroxyurea and blood transfusions, as well as the impact of transplantation on organ damage are likely to influence the timing and indication of transplantation. Improvements in preparative regimen may enable the safe use of alternate source of stem cells such as unrelated matched donors and further improve the applicability and acceptability of this treatment.     

Cognitive screening for silent cerebral infarction in children with sickle cell disease

Silent cerebral infarctions have been shown to cause major morbidity in children with sickle cell disease, suggesting that silent infarctions are not as "silent" as once thought. The current definition of silent infarction includes signal changes on magnetic resonance imaging, the absence of overt abnormalities on neurologic examination, and no history of focal neurologic event. Using a decision tree algorithm, we identified a cognitive profile distinguishing children with (n=16) and without (n=49) silent infarctions. The best model combined learning slope from the California Verbal Learning Test-Children's Version and Block Design from the Wechsler Abbreviated Scale of Intelligence. Accuracy was 75%, with 75% sensitivity and 76% specificity. Administration of a brief cognitive battery may be the most feasible approach to screen for silent infarctions in children with sickle cell disease.     

Ethical aspects of neonatal screening for sickle cell disease in Western European countries

Sickle cell disease raises some important ethical questions regarding neonatal screening in Western European countries such as France, England or Belgium, which have already introduced either universal or selective screening. Such screening is aimed at benefiting children affected with major sickle cell syndrome. It also detects heterozygous babies and, in doing so, heterozygous parents. The latter information, which is ignored most of the time, risks making parents feel guilty and can raise fears of stigmatization. Whether it would change their future reproductive decisions requires further studies, for cultural and religious reasons may have a strong negative influence on the request for prenatal diagnosis. Disclosure of the child's illness may oblige the family to remain in the country they have emigrated to because it offers the best chance of treatment. As a result, links between the family and its original community are modified. Parents must more or less sever links with their family in Africa and try to trust and adapt to the public health services in Europe.

Conclusion: Neonatal screening of sickle cell disease is highly ethical in facilitating the prevention of the early death of affected children. It also detects heterozygous parents and offers at-risk couples the possibility to perform a prenatal diagnosis during the next pregnancy. Adequate counselling must consider the risk of stigmatization that carrier status represents, especially for women in many cultural beliefs, and the numerous cultural and religious reasons which limit parental uptake for prenatal diagnosis. Disclosure of their child's illness may oblige immigrant families to stay in Europe, where free and adapted healthcare is available.     

Molecular analysis of Iranian families with sickle cell disease

Sickle hemoglobin is a mutant hemoglobin in which valine has been substituted for the glutamic acid normally at the sixth amino acid of the beta-globin chain. Detection of the single base pair mutation at codon 6 of the beta-globin gene is important for the prenatal diagnosis of sickle cell anemia and sickle cell disease. Application of the polymerase chain reaction technology to detect sickle cell patients and heterozygous carriers in a group of patients suspected for sickle cell disease was carried out. The sample was composed of 52 normal individuals and 52 unrelated outpatients who were attending the Hematology Research Center. All patients were interviewed. Results of their medical histories, physical examination, and the hematological analysis were recorded. The blood samples were collected in EDTA and genomic DNA was extracted from leukocytes. An amplified 110 base pair fragment of the beta-globin gene containing codon 6, was digested with the restriction enzyme MS II, and electerophoresed in 3 per cent agarose. We have established the technical condition for detection of sickle cell disease using a PCR assay. Fifteen patients having haemoglobin (Hb SS) and 37 patients in the heterozygous state (Hb AS) were identified. We confirm that the normal controls have the Hb AA genotype. The standardization of a highly sensitive and specific diagnostic test for sickle cell disease permitted us to identify the normal controls, the homozygotes and heterozygotes. This amplification method is rapid, sensitive and simple, and also has application research that is important for the prenatal diagnosis of sickle cell disease.