Screening Program For Hemoglobinopathies Research Articles

Hb TIGRAYE [β79(EF3)Asp → His] IN A CAUCASIAN FAMILY FROM SARDINIA

The occurrence of several abnormal hemoglobins (Hbs) in the population of the island of Sardinia has been documented [[1]]. Because of continuing screening programs for hemoglobinopathies among new...

Hemoglobin S haplotypes among sickle cell patients in the Puerto Rican population

The Hb S mutation has been associated with four major haplotypes of the β-like gene cluster in the African continent, which include the following: haplotype #19 or Benin; #20 or Bantu, or Central African Republic (CAR); #3 or Senegal; and #17 or Cameroon. Neonatal screening in Puerto Rico in recent years has shown an overall incidence of abnormal hemoglobins of 2.24%, including 1.87% Hb S and 0.31% of Hb C. It has been postulated that certain unique mutant sites linked to the β gene cluster haplotypes might be responsible, at least partly, for the differences in the fetal globin gene expression and clinical severity observed among sickle cell patients. The purpose of our study was to identify the haplotypes present in Puerto Rican Hb S patients to better characterize sickle cell disease in Puerto Rico. Blood samples from twenty nine individuals with sickle cell disease and other sickling syndromes were collected at the Neonatal Hemoglobinopathy Screening Program Clinic. All blood samples were analyzed by cellulose acetate, citrate agar and isoelectric focusing electrophoresis. β-globin gene haplotypes were analyzed by allele-specific oligonucleotide (ASO) probe hybridization and/or by PCR RFLP. The predominant haplotypes for the forty eight β5 chromosomes analyzed were the haplotype #19 (33%}, and haplotype #20 (33%). For the haplotype #3,31 mutation, 12.5% of the chromosomes presented the mutation. Mutations characteristic for haplotypes #10 and #11 were 8.34% of β5 chromosomes while 12.5% were mixed or other haplotypes. Comparing Puerto Rico with other countries, we have a prevalence of the Benin and Bantu haplotypes, differing with the United States prevalences in which more than 50% are Benin haplotypes. Our haplotype frequencies are similar to those found in a recent study from Cuba. The predominant haplotype in the SS population we studied (#19/20) is associated with a moderate clinical condition. In our studies a strict correlation with clinical severity and β5 haplotypes does not exist in all of the SS patients analyzed. We acknowledge support from NIH-RCMI G12-RR-03051 and the UPR School of Medicine.

Newborn screening for sickle cell disease: 4 years of experience from California's newborn screening program.

In this article we describe the success of a unique newborn screening program for sickle cell disease and other hemoglobinopathies. We will present and discuss 4 years of experience from the California Newborn Hemoglobinopathy Screening Program. Several aspects that ensure the success of the program will be reviewed. These aspects include (a) the use of high-pressure liquid chromatography as the initial screening technique, (b) a confirmatory testing laboratory that incorporates DNA technology and innovative protein analysis using electrospray mass spectrometry, and (c) a complex follow-up strategy that employs regional nurses to track positive results and ensure timely enrollment of infants into treatment systems. Of these 2 million infants screened, 492 were diagnosed with some form of sickle cell disease; 290 (58.9%) were diagnosed with hemoglobin SS, 143 (29.0%) were diagnosed with hemoglobin SC, and 47 (9.5%) were diagnosed with S beta+thalassemia. The prevalence and ethnicity data presented here demonstrate the ineffectiveness of targeted screening and justify universal screening. Had targeted screening been performed in California during the past 4 years, 58 nonblack infants with sickle cell disease would have gone undiagnosed, and 6,921 nonblack infants with sickle cell trait would not have been identified.

Prenatal Genetic Counseling for Hemoglobinopathy Carriers

Health personnel trained in medical genetics are insufficient to meet the demand for genetic services. Methods must be found to enable primary care providers to offer commonly needed genetic services themselves. In our recently reported community-wide prenatal screening program for hemoglobinopathies, 36% of women detected to have a hemoglobinopathy did not come to a tertiary center for counseling and thus may have not benefited from testing. To determine whether the efficiency of the program could be increased if counseling were provided by the prenatal care provider (obstetrician or family practitioner), we developed a pilot training program on the basis of our experience in offering such services and enlisted 68% of regional prenatal care providers to participate. The proportion of patients detected to have a hemoglobinopathy who received counseling was similar in the primary and tertiary provider groups: 59% versus 50%, respectively, for sickle trait, and 69% versus 66%, respectively, for beta-thalassemia trait. Knowledge after counseling was also similar for the primary and tertiary provider groups: 64% versus 66% (mean % correct), respectively, for sickle trait, and 79% versus 78%, respectively, for beta-thalassemia trait. However, the two provider groups significantly differed with regard to whether or not the patient had her partner tested. For sickle trait, it was 25% for the primary providers but 49% for the tertiary providers (P < .001). For beta-thalassemia trait, it was 47% for the primary providers but 78% for the tertiary providers (P < .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Hemoglobin C disease in infancy and childhood

We reviewed the clinical course, physical findings, and hematologic values in 16 pediatric patients with hemoglobin C disease, all but one identified by a newborn hemoglobinopathy screening program. The patients had few symptoms or physical findings. Height and weight percentiles were normal. Patients typically had a mild hemolytic anemia characterized by microcytosis and target cells. (J PEDIATR 1994;125:745-7)

Hemoglobin C disease in infancy and childhood.

We reviewed the clinical course, physical findings, and hematologic values in 16 pediatric patients with hemoglobin C disease, all but one identified by a newborn hemoglobinopathy screening program. The patients had a few symptoms or physical findings. Height and weight percentiles were normal. Patients typically had a mild hemolytic anemia characterized by microcytosis and target cells.

Genotypic confirmation from the original dried blood specimens in a neonatal hemoglobinopathy screening program.

Dried blood spots are used for newborn screening because of ease of sample collection, handling, and shipment. DNA is stable and accessible in the filter paper matrix. Genotypic confirmation using initial specimens is demonstrated for a regional screening program. Seventy-five blinded samples underwent DNA analysis after Hb electrophoresis. DNA was microextracted from a 1/2-inch semicircle (25 microL whole blood equivalent), amplified, and analyzed by four different methods. Direct amplification without microextraction and automated sequencing from microextracted DNA also was performed. All four analyses agreed for the A and S alleles in 70 of 75 specimens. Three disagreements were clarified by the other semicircle from the original sample: two were due to polymerase chain reaction contamination and one to contamination of one of four analytical tests. Two would have required analysis of a second specimen, one because of polymerase chain reaction failure and the second because the patient had S/beta-thalassemia. Direct amplification without microextraction was successful in an additional 77 of 78 specimens for analysis of the A, S, C, and E alleles. Automated direct sequencing from microextracted DNA was demonstrated for the A, S, and C alleles. Analysis of microextracted DNA from dried blood specimens for A and S alleles reduced the need for and costs of obtaining a second specimen for confirmation by 97%. Direct amplification without microextraction for analysis of A, S, and C alleles permits additional reduction in personnel time and costs. We have demonstrated that microextracted DNA is amenable to automated sequencing after asymmetric polymerase chain reaction. Direct genotypic confirmation can facilitate diagnosis and initiation of medical intervention.

Comparative Approach to the Evaluation of Hemoglobin A&lt;sub&gt;2&lt;/sub&gt; by Two Different Methods: High-Performance Liquid Chromatography and DE-52 Microchromatography

Hb A2 was determined in 477 subjects: 77 were affected by iron deficiency anemia, 172 were carriers of beta-thalassemia trait and 228 were normal controls. Hb A2 was determined by both DE-52 microchromatography and high-performance liquid chromatography (HPLC). The analysis of the data by linear regression demonstrated that the methods furnish overlapping results. Our findings show that HPLC is a rapid and easily reproduced method which allows a quantitative and qualitative discrimination of the various Hb fractions, making it a valid tool in screening programs for hemoglobinopathies.

Prenatal diagnosis for sickle cell disease. A survey of the United States and Canada.

Prenatal diagnoses for sickle cell disease in the United States and Canada numbered at least 1065 through the end of 1987. The 272 prenatal diagnoses in the United States in 1987 constituted only about 4.1% of the estimated pregnancies at risk. The termination rate for diagnosed fetuses was 39% for sickle cell anemia and 23% for hemoglobin SC disease. Prenatal hemoglobinopathy screening programs should not be judged solely on the number of terminations for affected fetuses. Other benefits are reassurance for couples shown to have an unaffected fetus and, for couples shown to have an affected fetus, preparation for the birth of a child requiring special care and information relevant to future childbearing.

PUBLIC PRESENTATIONS

I am the parent of an 11½-year-old daughter with sickle cell disease. I am aware of the need for a comprehensive newborn screening program for sickle cell disease and other hemoglobinopathies. However, all such programs must be instituted with a follow-up component, and parents should be made aware that such screenings are being done. My daughter was born during the summer of 1975 in New York City. New York City began screening for sickle cell and similar hemoglobinopathies in May 1975, but had no comprehensive follow-up program until 1978. My daughter was not screened nor was I aware of the screening program. I learned of my daughter's condition during a routine well-child clinic visit when she was 6 months of age. I am afraid to think of her outcome had I not been taking her for preventive health care, because before the age of 1 year she experienced one of the most life-threatening crises of a child with sickle cell disease—splenic sequestration. I am pleased to announce that in New York City today, parents are notified in a timely manner of their infant's newborn screening results with information regarding follow-up and counseling services. Two of my immediate family members gave birth to infants with sickle cell trait. They were informed of their infants' results within 2 weeks after their babies' births, and were given concrete information and recommendations for follow-up genetic services. I know a comprehensive newborn screening program will prevent mortality in infants found to have sickle cell disease and related hemoglobinopathies.

APPROACHES TO SCREENING

Georgia's newborn screening program for hemoglobinopathies has been evolving for more than 23 years. The program began in 1964 with the screening of infants at 6 months of age and progressed to the full-scale implementation of a statewide hemoglobinopathy newborn screening program in 1980. The program functions as a cooperative effort with several major components: two tertiary care centers, a community-based clinic, and the state public health department. The tertiary care centers consist of the Augusta Comprehensive Sickle Cell Center affiliated with the Medical College of Georgia and the Georgia Sickle Cell Center at Grady Hospital affiliated with Emory University School of Medicine. These two centers are responsible for patient care, education, and research. The community component consists of the Sickle Cell Foundation of Georgia, which is responsible for counceling clients with sickle cell trait, community education, and notification of parents of infants with normal test results. The state component consists of the Georgia Department of Human Resources, which is responsible for program administration and primary laboratory testing. The program components coordinate their services through a voluntary organization known as the Georgia Sickle Cell Task Force. The organization consists of representatives from agencies and organizations actively involved in the provision of services for patients with sickle cell disease. The members of this organization work together to ensure an efficient service network for education, testing, counseling, patient management, program monitoring, and evaluation. Georgia's screening program can best be described as a targeted, voluntary, mandatory screening program, which means that, unless the mother objects to having her infant tested on religious grounds, infants in 13 ethnic groups are automatically tested because they are considered at risk (African, Arabian, Central American, Greek, Maltese, Hispanic, Indian, Portuguese, Puerto Rican, Sardinian, Sicilian, South American, and Southern Asian).

Techniques' Comparison and Report of the North Carolina Experience

Controversy still exists as to the best laboratory method to use to screen newborns for sickle cell disease and other hemoglobinopathies. The proposed methods include hemoglobin electrophoresis, column chromatography, isoelectric focusing, and high performance liquid chromatography. There is also debate concerning the preferred method of sample collection. The proposed methods of sample collection include cord blood or blood obtained from the infant collected in a tube with anticoagulant or on filter paper. We compared hemoglobin electrophoresis patterns from infant blood samples collected in heparinized capillary tubes and on filter paper. This comparison was performed because hemoglobin electrophoresis of dried blood samples collected on filter paper has been advocated as a practical, reliable, and inexpensive method for mass screening programs, although the limitations of this technique have not been explored fully. We also summarize data from the North Carolina Newborn Hemoglobinopathy Screening Program, which relates to the advantages and limitations of hemoglobin electrophoresis from filter paper blood specimens. MATERIALS AND METHODS Specimens Four sets of specimens were used for this study: (1) specimens collected at Duke University Medical Center to compare hemoglobin electrophoresis patterns of hemolysates from filter paper and heparinized capillary tubes, (2) specimens collected by the North Carolina program for hemoglobinopathy screening, (3) specimens routinely collected at Duke University in heparinized capillary tubes for newborn hemoglobinopathy screening, and (4) samples for retesting to examine the error rate of the state program and to confirm screening results compatible with a hemoglobinopathy. Samples for Direct Comparison Between Filter Paper and Heparinized Specimens

Nursing Perspective

Newborn screening may be the single most important recent advance in the treatment of sickle cell disease. However, the efficacy of newborn screening depends on adequate patient education, counseling, and follow-up medical care. In large part, it is the nurse's responsibility to ensure that these follow-up services are provided. The Northern California Comprehensive Sickle Cell Center at Children's Hospital, Oakland, has a regional newborn hemoglobinopathy screening program that identifies approximately 15 newborns with sickle cell disease annually. Obstetrical nurses collect an umbilical cord blood sample from all babies born at the ten participating institutions. Samples are sent to the reference hemoglobinopathy laboratory at Children's Hospital, and diagnostic results are available within 1 week of birth. When a diagnosis of sickle cell disease is made, the genetic counselor discusses the case with the sickle cell nurse coordinator and physician. The responsible private physician and obstetrician are personally notified. In most cases, the family receives a telephone call from the genetic counselor approximately 1 week after the birth. An appointment is then made in the next week for laboratory confirmation of diagnosis and initiation of counseling. At the confirmation appointment, the family and patient are introduced to the sickle cell nurse coordinator, and a comprehensive sickle cell clinic appointment is made for the following week. At this appointment, a "new family letter" introducing the rest of the sickle cell staff is reviewed with the family by the nurse, and a copy is given to the family. This letter outlines the comprehensive services available to patients and contains information to familiarize them with our particular clinical services and policies.

Evaluation of eight and a half years of neonatal screening for haemoglobinopathies in Birmingham.

A pilot neonatal screening programme for haemoglobinopathies linked with screening for phenylketonuria and congenital hypothyroidism was reviewed. During 1978 to December 1986 137,000 neonates were tested. There were improvements in the detection rate and accuracy of diagnosis for homozygotes and mixed heterozygotes, mainly associated with the introduction of citrate agarose gel electrophoresis as a follow up procedure on all specimens showing any abnormality on the initial cellulose acetate electrophoresis. We recommend that the programme is continued on a service basis.

Uses of available record systems in epidemiologic studies of reproductive toxicology

The uses of available record systems in epidemiologic studies of reproductive toxicology are described with reference to New York State. The available record systems (and relevant reproductive end points) described include: a newborn screening program for metabolic diseases and hemoglobinopathies (relevant to point mutations); chromosome registries and prenatal cytogenetics (for chromosome anomalies); live birth certificates (for birth defects, birthweight, sex ratio, etc); fetal death certificates (for spontaneous fetal deaths); and a statewide cancer registry (for childhood cancers and transplacental carcinogenesis). The uses and limitations of these record systems are discussed, along with examples of their use in descriptive and analytic epidemiologic studies. Descriptive studies outlined include investigations of temporal and geographic trends in birth defects, birth weight, and fetal deaths, with reference to environmental questions (eg, Love Canal, nuclear power plants). Analytic studies described concern parental occupation in relation to specific birth defects (neural tube defects and Down syndrome) and maternal use of contraceptive drugs.

361 CORD BLOOD SCREENING FOR SICKLE HEMOGLOBINS: EVIDENCE FOR FEMALE PREPONDERANCE OF HEMOGLOBIN S

Since June, 1972, we have conducted a comprehensive umbilical cord blood screening program for sickle hemoglobinopathies at Yale-New Haven Hospital. When we recently noticed an apparent preponderance of females with hemoglobins AS and SS, we decided to analyze the results of the first 65 months of screening. An FAS hemoglobin pattern (sickle cell trait) was detected in 162/1959 black females vs. 129/2017 in black males (X2=5.14,P<.05). For the FS hemoglobin pattern (sickle cell anemia and sickle β-thalassemia), the difference was even more striking: 15/1959 in black females vs. 4/2017 in black males (X2=6.73,P<.01). For 704 Puerto Rican newborns, the incidence of sickle cell trait was very low (2.1% overall), and there were no significant female-male differences. Excluding the two children with FS cord blood electrophoreses who were subsequently shown to have sickle β-thalassemia, there were 17 black newborns with hemoglobin SS among the first 3976 black births since the inception of the screening program. This represents an incidence of 1 in 234 live births, which far exceeds the 1 in 750 predicted by the Hardy-Weinberg equation. The excess of observed over predicted SS newborns is almost entirely accounted for by the high incidence in black females, 1 in 150. Hemoglobin S may confer a selective advantage in utero that is more marked in females.

A test for abnormal hemoglobins in umbilical cord blood.

This article describes a rapid, simple, and inexpensive method for testing the cord blood of infants for the common hemoglobinopathies by electrophoresis using cellulose polyacetate strips. In a study of 7,500 umbilical cord blood specimens, 11% were found to contain an abnormal hemoglobin. While the importance of evaluating cord blood in a screening program for hemoglobinopathies is evident, the procedure must be accurate, verified, and followed by proper counseling.

Laboratory diagnosis of hemoglobinopathies

A successful voluntary hemoglobinopathy screening program should have as its goals effective, accurate counseling, preventive medicine, and education. Techniques that detect only the presence of hemoglobin S would not allow these goals to be fulfilled. The Center for Disease Control is currently offering training courses in laboratory methods of hemoglobinopathy detection for anyone involved in hemoglobinopathy screening. These courses, which are free, stress cellulose acetate electrophoresis as the initial screening test. Besides being inexpensive, the test is easy to perform, allows differentiation of sickle cell disease (eg, SS, SC) from the relatively benign carrier state, and detects other common hemoglobin abnormalities so that effective counseling is possible. The solubility (dithionite) test is used to confirm the presence of a sickling hemoglobin.

Laboratory Diagnosis of Hemoglobinopathies

A successful voluntary hemoglobinopathy screening program should have as its goals effective, accurate counseling, preventive medicine, and education. Techniques that detect only the presence of hemoglobin S would not allow these goals to be fulfilled. The Center for Disease Control is currently offering training courses in laboratory methods of hemoglobinopathy detection for anyone involved in hemoglobinopathy screening. These courses, which are free, stress cellulose acetate electrophoresis as the initial screening test. Besides being inexpensive, the test is easy to perform, allows differentiation of sickle cell disease (eg, SS, SC) from the relatively benign carrier state, and detects other common hemoglobin abnormalities so that effective counseling is possible. The solubility (dithionite) test is used to confirm the presence of a sickling hemoglobin.

A Comprehensive Screening Program for Hemoglobinopathies

A comprehensive screening program for hemoglobinopathies, established in April 1970, includes a ten-minute cellulose acetate electrophoresis procedure for primary screening, additional laboratory studies for specific diagnosis, and clinical follow-up by neighborhood health center physicians. The simple screening test costs approximately 5 cents per sample and uses hemolysates prepared from packed unwashed red blood cells collected in microcapillary tubes. The electrophoresis procedure was easily learned by inexperienced volunteer technologists. During the first eight months, 107 of 1,000 health center patients and 63 of 358 hospital patients had hemoglobinopathies diagnosed. The basic screening method can distinguish sickle cell trait, sickle cell disease, and sickle cell-hemoglobin C disease. The comprehensive nature of the screening program is further demonstrated by the detection of patients with thalassemia minor, hereditary persistence of hemoglobin F, and hemoglobin types AC, CC, and B 2 .