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Biomedical subjects

Fred Lorey

Publications and source records attributed to Fred Lorey.

11 recordsLinked to original sources

Retrospective determination of ceruloplasmin in newborn screening blood spots of patients with Wilson disease.

Wilson disease is an autosomal recessive disorder of copper transport, caused by the reduced or absent function of the Wilson disease gene ATP7B on chromosome 13. The disease is characterized by reduced incorporation of copper into the ceruloplasmin protein and reduced excretion of copper into the bile. Wilson disease is effectively treated if detected early. Our study goals were to determine the feasibility of a population screening for Wilson disease using dried blood spots and to characterize the base-line ceruloplasmin concentration in newborn blood spots of patients with Wilson disease. Ceruloplasmin was analyzed in dried blood spots obtained from 353 Mayo Clinic pediatric volunteers aged from 3 months to 18 years and from 1045 anonymous newborn screening specimens using a sandwich enzyme-linked immunosorbent assay. The original newborn screening blood spots were retrieved from two patients with Wilson disease along with age-matched controls for ceruloplasmin determination. The mean (+/-SD) concentration of ceruloplasmin in the pediatric blood spots was 40.0+/-14.4 mg/dL (range 13.1 to >60 mg/dL) and newborn blood spots was 47.2+/-15.5mg/dL (range 6.5 to >60 mg/dL). Ceruloplasmin in the newborn blood spots from two Wilson disease patients were 2.6 and 2.8 mg/dL, respectively. The newborns affected with Wilson disease had significantly lower ceruloplasmin levels in blood spots than unaffected newborns. These findings support that presymptomatic screening for Wilson disease using dried blood spots could be possible, even in the newborn period.

Adenosine Triphosphatases↗

Pilot programs in newborn screening.

The term "pilot study" has been used over the years to describe the evaluation of the many elements involved in deciding whether a proposed condition should be added to a newborn screening (NBS) panel, and until recently, was unilaterally used to describe the evaluation of the assay to be used before the condition was officially adopted by a state for its newborn screening panel. Since Guthrie's introduction of screening for PKU, each time a new condition was added to the panel, the screening assay itself was validated through a population-based trial, in which the test was performed with de-identified samples to avoid association between the test result and the infant. This is considered by the laboratory as the "pilot phase" of adding a new condition. To advance the science of NBS, especially to accommodate new technologies that may provide new types of information (genetic versus physiological) for each new condition, pilot programs are essential. Involvement of the clinical community serves to improve these evaluations and provides the needed clinical validation of decisions made as a result of it. This paper describes the historical context of pilot programs in population-based NBS that utilize laboratory-based markers as indicators of concern; specifically, three applications that demonstrate different approaches to the use of pilots in adding conditions to a NBS panel are described.

Diffusion of Innovation↗

Prevalence of HFE mutations in California newborns.

Advances in molecular diagnostics have led to an increased interest in expanding population-based screening to include genetic diseases that occur outside the newborn period. Hereditary hemochromatosis may be a candidate for large-scale screening in populations with a high prevalence of the common HFE mutations. To determine race-specific frequencies of the HFE mutations, C282Y and H63D, the authors applied an automated, high-throughput genotyping method to dried blood spot samples from a representative population of California newborns. In this sample of 3989 newborns, C282Y and H63D allele frequencies were highest in white (C282Y: 5.5 +/- 0.5%; H63D: 13.4 +/- 0.76%) and Hispanic (C282Y: 1.8 +/- 0.29%; H63D: 11.9 +/- 0.72%) newborns, and lowest in black (C282Y: 1.3 +/- 0.25%; H63D: 3.0 +/- 0.38%) and Asian (C282Y 0.5 +/- 0.16%; H63D 2.9 +/- 0.37%) newborns. The estimated prevalence of C282Y homozygotes in this multiracial population is 1.4/1000. As additional genetic and environmental risk factors for HHC are identified, neonatal screening may become an acceptable strategy to follow susceptible individuals and prevent clinical disease.

California↗

California's experience implementing a pilot newborn supplemental screening program using tandem mass spectrometry.

OBJECTIVE: In response to a California legislative mandate, a pilot tandem mass spectrometry (MS/MS) screening program was undertaken by the Genetic Disease Branch of the California Department of Health Services between January 2002 and June 2003. This article outlines the Genetic Disease Branch approach to implementing the MS/MS pilot program and the program evaluation strategies used. METHODS: Through the use of multiple data collection methods, we were able to describe hospital participation patterns, screening test uptake, screening test performance, follow-up services utilization, and provider and family satisfaction with the educational materials and follow-up services provided. RESULTS: During the 18-month pilot program, just more than one half of California's 755,698 newborns were offered MS/MS screening; among this group, 90% of parents chose to have their newborns screened. Fifty-one newborns were identified with MS/MS-detectable disorders, among 461 patients referred for follow-up testing (0.13% of the screened population). One disorder was diagnosed successfully for every 6939 newborns screened and for every 9 infants referred (excluding phenylketonuria). The overall California population prevalence of MS/MS-detectable disorders was 1 case per 6500 infants (excluding phenylketonuria). The positive predictive value for medium-chain acyl-CoA dehydrogenase deficiency was 86.7%, whereas the positive predictive value for short-chain acyl-CoA dehydrogenase deficiency was 21.6%. For a sample from Hawaii, 1 isovaleric aciduria case was detected among 6132 newborns. CONCLUSIONS: Evaluation of the California MS/MS screening pilot program demonstrated that this technology was effective in identifying additional metabolic disorders. The positive predictive value of screening was particularly good for medium-chain acyl-CoA dehydrogenase deficiency. Overall, patient referral rates were very acceptable. The utility of the program was also demonstrated by positive reviews from patients and providers.

California↗

Changes in the epidemiology of thalassemia in North America: a new minority disease.

OBJECTIVE: Changing patterns of immigration to North America, along with improved treatment, have altered the clinical spectrum of thalassemia, one of the world's most common genetic diseases. The new demography of the disease, with its widely variable phenotypes, has implications for its diagnosis, counseling, and management. Characterization of the new spectrum of this ancient disease, now predominated by minority groups, is essential for optimizing survival. METHODS: The National Institutes of Health-sponsored North American Thalassemia Clinical Research Network (TCRN) conducted a cross-sectional study of 721 patients with thalassemia syndromes. A detailed chart review was undertaken to define the relationships between ethnic origins, genotype, and phenotype. These results were compared with 3 previous surveys of similar regions. To determine if the TCRN patient epidemiology is representative of North American patients, 87 additional programs were reviewed, and hemoglobinopathy programs from the 2 largest thalassemia regions, Ontario and California, were analyzed. RESULTS: A total of 721 patients completed analysis in the TCRN study, including 389 (54%) patients with beta-thalassemia major, 105 (15%) patients with beta-thalassemia intermedia, 95 (13%) patients with hemoglobin E-beta-thalassemia, and 132 (18%) patients with alpha-thalassemia. beta-Thalassemia predominated in Eastern North America. Hemoglobin E-beta-thalassemia and alpha-thalassemia were common on the Western continent. Genotype broadly correlated with the clinical phenotype. However, there was marked heterogeneity in clinical phenotype among patients with similar globin mutations. In beta-thalassemia disorders, coinheritance of the alpha-thalassemia trait, triplication of alpha-thalassemia genes, and heterozygosity for the dominant beta-thalassemia allele affected the clinical phenotype. In alpha-thalassemia disorders, structural mutations such as hemoglobin H-Constant Spring resulted in a severe hemoglobin H phenotype. Sixty percent of patients received regular transfusions, and 86% received regular iron-chelation therapy. Increased survival and decreasing birth rates of Mediterranean patients resulted in an aging Greek/Italian population being replaced by a young Asian/Middle Eastern population. Now, Asian patients account for >50% of the thalassemia population. Evidence of increasing survival is reflected in an advancing mean age of white patients with thalassemia major (25 years, up from 11 years in 1974). The results of the non-TCRN thalassemia survey confirm these observations and describe a young multiethnic thalassemia population distributed throughout North America. Newborn-screening results suggest that thalassemia births in North America are increasing and reflect the change in genotype and phenotype observed in the TCRN populations. CONCLUSIONS: The epidemiology of thalassemia in North America reflects a heterogeneous group of diseases with new ethnicities, genotypes, and phenotypes. In these communities, physicians will need to provide education, prenatal diagnosis, counseling, and management of this newly diverse group of patients.

Adolescent↗

Molecular genetic confirmatory testing from newborn screening samples for the common African-American, Asian Indian, Southeast Asian, and Chinese beta-thalassemia mutations.

beta-Thalassemia is a serious health problem in the United States, especially in California, due to increased Asian immigration. Neonatal screening by using high-performance liquid chromatography (HPLC) or isoelectric focusing (IEF) may lead to confusion due to interactions of various hemoglobinopathies with beta-thalassemia. Our purpose was to develop single-tube multiplexed PCR assays using original neonatal screening specimens to identify the mutations responsible for beta-thalassemia in order to expedite diagnostic confirmation. Primers were designed for two to six common ethnic-specific mutations using the amplification refractory mutation system (ARMS). This multiplex ARMS approach was standardized using DNA samples with known mutations for beta-thalassemia in those of Asian (Southeast Asian, Chinese, and Asian Indian) and African-American descent. Specimens from African-American neonates were tested for two mutations (-88 and -29); Asian Indians for five mutations (IVSI-1, IVSI-5, codons (Cd) 41/42, Cd 8/9, and 619-bp deletion); Chinese, Taiwanese, and Southeast Asians for seven mutations (Cd 41/42, Cd 17, -28, IVSII-654, Cd 71/72, IVSI-5, and IVSI-1). We identified each of these beta-thalassemia mutations in multiplexed ARMS from positive control samples. We tested 25 anonymized dried blood specimens from neonates who had been diagnosed with beta-thalassemia and who also belonged to these ethnic groups. We detected a mutation specific to the neonate's ethnic group using the ARMS approach in nearly all specimens, and the results were confirmed by sequencing. Multiplexed ARMS for ethnic-specific beta-thalassemia mutations from the original newborn screening dried blood specimens is a rapid and efficient approach for diagnostic confirmation.

Asian People↗

The timing of demise in fetuses with trisomy 21 and trisomy 18.

OBJECTIVE: Women with chromosomally abnormal fetuses often choose to continue their pregnancy. However, though they may search for specific details whether their fetus will survive, not much information is available. We sought to determine if there was a pattern for timing of demise and to determine if demise was more likely to occur before viability in fetuses with amniocentesis confirmed trisomy 18 or 21. METHODS: From the California Expanded AFP screening program, 1813 women were identified to have a fetus with trisomy 18 or 21. Of these, 392 women with trisomy 21 and 106 with trisomy 18 continued the pregnancy. Pregnancies ending in fetal demise were analyzed for gestational age at demise. RESULTS: Of the trisomy 21 fetuses, 40 (10.2%) demised and of the trisomy 18 fetuses, 34 (32.1%) demised. The mean gestational age at time of fetal demise was 28.9+/-1.3 weeks SE for trisomy 21 and 32.1+/-1.2 weeks SE for trisomy 18 (p=0.09). There was no clustering of losses as losses were uniformly distributed throughout gestation after 24 weeks. A slightly larger proportion of T-21 (37.1%) losses occurred before viability (24 weeks) compared to those with T-18 (14.8%) (p=0.05). CONCLUSION: It appears that after 24 weeks' gestation, there is no specific time for fetal demise in fetuses affected by trisomy 21 or 18. There may be an association between trisomy 21 and stillbirth prior to viability. This information may be helpful in counseling those patients found to have a chromosomally abnormal fetus who choose to continue their pregnancy.

Adult↗

Adult hemoglobin levels at birth and risk of sudden infant death syndrome.

BACKGROUND: During the final weeks of gestation, infants normally begin a transition from the production of fetal to adult hemoglobin. Delayed or faulty transition to the production of adult hemoglobin might play a role in the etiology of sudden infant death syndrome (SIDS). OBJECTIVE: To examine the association between adult hemoglobin levels measured at birth and the subsequent risk of SIDS. DESIGN AND SETTING: Cohort study of all infants born in California between March 1, 1990, and December 31, 1997, who were enrolled in the state's Newborn Screening Program and followed up during the first year of life to identify deaths attributed to SIDS. PARTICIPANTS: Population-based sample of 3.2 million infants. MAIN OUTCOME MEASURE: Risk of death attributed to SIDS. RESULTS: The study included 2425 infants whose deaths were attributed to SIDS. There was an inverse relationship between adult hemoglobin level, expressed as a percentage of total hemoglobin, and the subsequent incidence of SIDS. After adjustment for infant sex, race/ethnicity, length of gestation, maternal age, maternal education, maternal smoking, intrauterine growth restriction, and preeclampsia/eclampsia, the relative risks of SIDS for infants in the lower 4 quintiles of adult hemoglobin level were, in descending order, 1.12 (95% confidence interval [CI], 0.96-1.32), 1.38 (95% CI, 1.19-1.59), 1.55 (95% CI, 1.34-1.80), and 2.15 (95% CI, 1.87-2.47) compared with infants in the highest quintile. CONCLUSIONS: These findings suggest that infants with low levels of adult hemoglobin in the first hours after birth are at elevated risk of SIDS. Delayed maturation in production of adult hemoglobin may play a role in the etiology of some SIDS cases.

California↗

DNA banking for epidemiologic studies: a review of current practices.

To study genetic risk factors for common diseases, researchers have begun collecting DNA specimens in large epidemiologic studies and surveys. However, little information is available to guide researchers in selecting the most appropriate specimens. In an effort to gather the best information for the selection of specimens for these studies, we convened a meeting of scientists engaged in DNA banking for large epidemiologic studies. In this discussion, we review the information presented at that meeting in the context of recent published information. Factors to be considered in choosing the appropriate specimens for epidemiologic studies include quality and quantity of DNA, convenience of collection and storage, cost, and ability to accommodate future needs for genotyping. We focus on four types of specimens that are stored in these banks: (1) whole blood preserved as dried blood spots; (2) whole blood from which genomic DNA is isolated, (3) immortalized lymphocytes from whole blood or separated lymphocytes, prepared immediately or subsequent to cryopreservation; and (4) buccal epithelial cells. Each of the specimens discussed is useful for epidemiologic studies according to specific needs, which we enumerate in our conclusions.

Biological Specimen Banks↗

Characterization of beta-globin haplotypes using blood spots from a population-based cohort of newborns with homozygous HbS.

PURPOSE: A population-based cohort from three state newborn screening programs was used to describe beta-globin gene cluster variation. METHODS: Blood spots from newborns homozygous for HbS were genotyped for five restriction fragment length polymorphisms (RFLPs) to construct beta-globin haplotypes. Haplotype distributions were compared by race/ethnicity and sex. Expected heterozygosities were calculated and compared with observed heterozygosities. RESULTS: Haplotype distributions did not differ between sexes for either blacks or Hispanics. Neither racial/ethnic group deviated from Hardy-Weinberg equilibrium; however, Hispanics had higher heterozygosity at two RFLPs compared with blacks. CONCLUSION: The differences between populations probably reflect recent migration and admixture rather than selection.

Anemia, Sickle Cell↗