Newborn Specimens Research Articles

Somatostatin, galanin and peptide histidine isoleucine in the newborn and adult human trigeminal ganglion and spinal nucleus: Immunohistochemistry, neuronal morphometry and colocalization with substance P

By means of indirect immunofluorescence the neuropeptides somatostatin, galanin and peptide histidine isoleucine were localized in cell bodies, nerve fibres and terminal-like elements in the ganglion and spinal nucleus of the human trigeminal nerve in perinatal and adult ages. No immunoreactivity to vasoactive intestinal polypeptide was observed. In the gasserian ganglion somatostatin-, galanin- and peptide histidine isoleucine-containing neurons and nerve fibres occurred frequently in pre- and full-term newborns, but were scarce to absent in adults. Somatostatin- and galanin-positive pericellular basket-like structures around non-immunoreactive perikarya were observed in newborn specimens. Immunoreactivity to somatostatin, galanin and peptide histidine isoleucine labelled nerve fibers and punctate and felt-like nerve terminals in the pars interpolaris and subnucleus caudalis of the spinal trigeminal nucleus, with immunostaining and distribution patterns characteristic for each peptide. In addition, somatostatin-containing neuronal cell bodies frequently were detected. At variance with those containing somatostatin, the number of galanin- and peptide histidine isoleucine-like immunoreactive elements were dramatically reduced in the adult tissue compared to the newborn one. Double immunostaining revealed that each of the three peptides partially colocalizes with substance P, the degree of coexistence being very low for somatostatin/substance P and high for galanin/substance P and peptide histidine isoleucine/substance P both in the gasserian ganglion and in the spinal nucleus. The results obtained suggest that somatostatin, galanin and peptide histidine isoleucine may play functional roles in primary sensory neurons and at the first synaptic level of the human trigeminal sensory system.

Effect of specimen collection method on newborn screening for PKU

Introduction: Although heelstick followed by direct spotting of blood on filter paper is usually the method of choice for routine newborn screening of phenylketonuria (PKU) and other disorders, current National Committee for Clinical Laboratory Standards (NCCLS) recommendations provide guidelines for blood collection by capillary tube and dorsal vein, finding that these methods are acceptable alternatives. These latter methods are used for newborn blood collection by a number of hospitals in the US. In large newborn screening programs, however, standardization and cutoffs are set by large-scale testing of specimens collected by direct spotting on filter paper. Methods: Three separate groups of 21 149, 111 035, and 120 837 newborn filter paper specimens were analyzed for phenylalanine concentration by a fluorometric method to determine the effect of collection method of phenylalanine values. The three methods examined were direct spotting of blood from heelstick on filter paper, collection of blood into capillary tube with transfer to filter paper and dorsal hand venipuncture with transfer to filter paper. Results: The mean phenylalanine levels were 2.63 mg/dl, 2.46 mg/dl, and 2.28 mg/dl for direct spotting, capillary tube, and dorsal hand vein, respectively. Actual presumptive positive rates for the three methods were 23 10 000 , 11 10 000 and 0 10 000 , respectively. These differences were consistent when controlling for laboratory and Area Genetic Center (AGC) origin. Discussion: Since guidelines generally recommend or require direct spotting, values obtained by this method should remain the standard for setting cutoffs; deviations from this method could lead to missed cases, particularly for early-tested infants with borderline elevated values.

Validity of screening early collected newborn specimens for phenylketonuria using a fluorometric method

During 1980 through 1991 serial phenylalanine testing using a fluorometric method was performed on newborns with a phenylketonuric sibling. The purpose of serial testing was to determine the blood phenylalanine levels during the first 24 h of life in those newborns with PKU in this at-risk cohort. Eighteen newborns had serial phenylalanine testing by filter paper or serum sampling within the first 24 h of life. Another six infants who missed the serial testing had a routine newborn screening collected between 24 and 72 h of age. Fifteen of the 24 newborns were found to have PKU and the remaining nine were unaffected. All the newborns with PKU tested by filter paper specimens had phenylalanine levels > 4.3 mg/dl by 6 h of age (normal < 4.3 mg/dl). Those newborns with PKU studied by serum sampling had levels > 4.2 mg/dl by 12 h of age (normal < 4.0 mg/dl). By 24 h after birth the mean measured increase of phenylalanine levels from cord blood was 4.4 and 3.6 mg/dl for filter paper and serum specimens, respectively. Unaffected newborns did not exhibit such an increase in their phenylalanine levels. Our data suggest that the fluorometric method for phenylalanine testing in PKU screening is sensitive in identifying affected newborns at the minimum age of 12 h. This experience supports the California Newborn Screening Program's policy of not re-screening newborns whose blood specimen is collected before 24 h of age when a fluorometric assay for phenylalanine is the screening test. Recognizing the still small sample size of this study, additional serial phenylalanine studies will be obtained. Routine or frequent repeat screening for PKU is not uniformly practiced in the United States. About 16% of the nation's newborns are re-screened when the initial screening; result is normal. Data on re-screening has shown low compliance and very low case yield. Missed cases of PKU are much more likely related to other screening program factors rather than testing when the infant is less than 24 h of age.

Erythrocyte uridine diphosphate galactose-4-epimerase deficiency identified by newborn screening for galactosemia in the United States

Eight infants (two whites and six blacks) with erythrocyte uridine diphosphate galactose-4-epimerase (epimerase) deficiency were identified in four newborn screening programs for galactosemia in the United States. The initial biochemical findings in all cases were elevated blood galactose-l-phosphate with normal or only slightly increased blood galactose and normal galactose-l-phosphate uridyltransferase (GALT) activity. Epimerase deficiency was confirmed in erythrocytes by a two-step enzymatic assay involving fluorometric measurements of NADH generated by coupling the uridine diphosphate glucose dehydrogenase reaction to epimerase. Seven of the eight infants appeared to be clinically normal at birth and one newborn had neonatal jaundice. The infrequent recognition of epimerase deficiency is likely due to the methods of newborn screening for galactosemia which are often only for GALT deficiency and perhaps also due to incomplete follow-up of increased metabolite levels in newborn blood specimens with normal GALT activity. Our results confirm a preliminary report of a high frequency of erythrocyte epimerase deficiency in the American black population.

Accurate detection of maternal antibodies to HIV in newborn whole blood dried on filter paper.

The testing of neonatal blood specimens dried on filter paper for maternal HIV antibodies, using an enzyme immunoassay (EIA) with confirmation of repeatedly reactive specimens by immunoblot (IB), was first described in 1987. It has been used to conduct large, unlinked, anonymous HIV seroprevalence surveys for surveillance of HIV in child-bearing women in several countries. We directly assessed the sensitivity and specificity of this combination of tests to detect maternal HIV antibodies. Serum samples obtained from mothers delivering at a major hospital in Kinshasa, Zaire were screened for HIV antibody using the rapid assay HIVCHEK. Plasma from HIVCHEK-positive women and age-matched negative controls were tested by enzyme-linked immunosorbent assay (ELISA); repeatedly reactive specimens were confirmed by Western blot (WB). Two days after delivery, whole blood was obtained from each newborn by heel-stick, dried on filter paper, and tested by EIA. Repeatedly reactive specimens were confirmed by IB. The serologic status of neonatal filter-paper specimens was compared with that of corresponding maternal plasma. The testing of neonatal filter-paper specimens using EIA, with confirmatory testing of repeatedly reactive specimens using IB, was 100.0% sensitive [of the 192 ELISA-positive and WB-positive maternal plasma specimens, 192 of the corresponding newborn filter-paper specimens were EIA-positive and IB-positive; 95% confidence interval (CI), 98.1-100]. The detection of maternal HIV antibodies was 99.6% specific using this combination of tests (of the 281 ELISA-negative or ELISA-positive but WB-negative maternal plasma samples, 280 of the corresponding newborn filter-paper specimens were EIA-negative or EIA-positive but IB-negative; 95% CI, 98.0-100). Maternal HIV antibodies can be detected accurately by testing neonatal blood dried on filter paper, using EIA with confirmation of repeatedly reactive specimens by IB. This approach can facilitate the determination of HIV seroprevalence in child-bearing women in countries with neonatal screening programs, or where serum or plasma is difficult to obtain.

Perinatally acquired human immunodeficiency virus infection

To evaluate factors that may affect the timely diagnosis of children with human immunodeficiency virus (HIV) infection, we compared data derived from two population-based pediatric HIV studies. Data from anonymous newborn HIV serosurveys were used to estimate the number of children born to HIV-seropositive mothers. A statewide active surveillance project determined the number of HIV-exposed children who had been clinically recognized. Of 88,732 Massachusetts newborn specimens tested anonymously for HIV antibodies during a 12-month period (November, 1987, to October, 1988), 223 were positive. As of October, 1991, 78 of these children (35%) had been identified by a statewide network of infectious disease physicians. HIV-exposed children born in inner city hospitals were more likely to have come to medical attention than those born in suburban hospitals (47% vs. 17%). Among the 29 children with confirmed HIV infection (13% of 223), the initial evaluation for HIV occurred at an earlier age among children born in inner city hospitals than among children born in other areas. HIV testing practices that rely heavily on risk assessment may result in delayed diagnosis of HIV infection in children whose mothers are not perceived to be at risk.

Pathological and biochemical changes induced in mice after intramuscular injection of venom from newborn specimens of the snake Bothrops asper (Terciopelo)

Venom from newborn Bothrops asper snakes has higher lethal, hemorrhagic, edema-forming, proteolytic and defibrinating activities than venom from adult B. asper specimens. Electrophoretic analysis confirmed the variation between these venoms. Intramuscular injection of 100 μg of venom from newborn specimens in mice induced defibrination, together with moderate increments of serum levels of lactate dehydrogenase, creatine kinase, hemoglobin and total proteins. A conspicuous hemorrhage developed in injected muscle rapidly after envenomation, probably due to a drastic alteration in capillaries and larger blood vessels. Other histological alterations included moderate myonecrosis, lung collapse and prominent renal damage, characterized by tubular necrosis and hyalinization. Polyvalent antivenom effectively neutralized lethal, hemorrhagic and indirect hemolytic activities of newborn B. asper venom, although requiring higher antivenom doses than neutralization of venom from adult B. asper.

Individual expression patterns of myotoxin isoforms in the venom of the snake Bothrops asper

1. 1. In order to investigate the distribution of myotoxin isoforms in the snake Bothrops asper, venoms from individual specimens were analyzed by a cathodic system for basic proteins under native conditions. 2. 2. The electrophoretic resolved at least five bands with slight differencesin mobility, corresponding to the fastest migrating proteins in the venom. The identity of the bands was confirmed by immunoblotting, using a rabbit anti-myotoxin serum. 3. 3. There were clear differences in the individual patterns of myotoxin isoform expression, both in specimens from the Altlantic and Pacific regions of Costa Rica. Some individuals possessed all five variants 4. 4. In agreement with previous reports, the venoms of ten newborn (less than 10 days of age) specimens completely lacked myotoxin bands, indicating on ontogenetic regulation in the expression of these toxins in B. asper. 5. 5. One of the bands, corresponding to the lysine-49 phospholipase myotoxin II, was the only isoform present in all individuals studied, suggesting a possible selective pressure for the conservation of this type of protein in the venom of B. asper.

Perinatal Human Immunodeficiency Virus (HIV) Testing

PERINATAL INFECTIONS The primary route of human immunodeficiency virus (HIV) infection in infants is vertical transmission from HIV-infected mothers. This is of particular concern as the number of infected women and the number of children infected by perinatal transmission continue to increase rapidly. The number of perinatally acquired acquired immunodeficiency syndrome (AIDS) cases increased 17% in 1989 and 21% in 1990. Similarly, the number of heterosexually acquired AIDS cases increased 27% in 1989 and 40% in 1990. There is evidence that vertical transmission of HIV can occur in utero (congenital/transplacental, similar to rubella),1,2 in the postpartum period (breast-feeding), and perhaps in the intrapartum period (similar to hepatitis B).3 The relative frequency and efficiency of transmission during each of these periods remains uncertain. The best estimates of vertical transmission from an HIV-seropositive mother to the fetus range from 12.9% to 39%4-6 Although the risk of transmission appears to be increased in women who are symptomatic, this point is still unclear.5 Preliminary information suggests that the presence of high levels of high-affinity/avidity antibodies to specific epitopes of the gp 120 of HIV may be protective and may decrease or prevent vertical transmission,7-10 although others have not been able to confirm this finding.11 More detailed information on perinatal HIV infection,12 and infection control13 in pediatric HIV infection is available in previously published statements from the AAP Task Force on Pediatric AIDS. SEROPREVALENCE Anonymous seroprevalence data from newborn specimens are being collected in 44 states, Puerto Rico, and the District of Columbia. In some states, seroprevalence data are available by metropolitan area and/or by hospital of birth.

Evaluation of a microtiter plate fluorescent-antibody assay for rapid detection of human cytomegalovirus infection.

The use of monoclonal antibody (MAb) p63-27, which is reactive with the major immediate-early human cytomegalovirus (HCMV) protein pp72, was explored for the rapid diagnosis of HCMV viruria. The rapid assay detected all but 1 of 19 specimens identified by standard virus isolation methods from 1,676 newborn urine specimens, achieving a sensitivity of 94.5% and a specificity of 100%. The monoclonal antibody recognized 260 randomly obtained clinical isolates of HCMV, indicating the suitability of this reagent for use in screening assays. The sensitivity of the microtiter plate method declined rapidly for specimen from older infants and children with congenital CMV infection and virus-infected children attending a day-care center and was judged to be unacceptable for screening populations in this age group.

Drug resistance and plasmid profile of shigellae in Taiwan.

One hundred and twenty-eight shigella strains isolated from newborn and infant human faecal specimens at Kaohsiung Medical College Hospital in Taiwan were serogrouped, serotyped and examined for drug-resistance patterns and for the presence of plasmids. Forty-seven per cent of the isolates were found to belong to the Shigella sonnei serogroup, 41% to the S. flexneri group, 9% to the S. boydii group and 3% to the S. dysenteriae group. The serotype with the greatest number of strains was S. sonnei I. (29%) followed by S. flexneri 1 (27%). Each strain was tested for resistance to 11 antimicrobial agents. Eight-eight per cent of the strains were resistant to tetracycline, 87% to chloramphenicol, 84% to streptomycin, 52% to ampicillin, 25% to nalidixic acid, 29% to kanamycin, 11% to cephalothin, 11% to neomycin, 10% to cotrimoxazole, 1% to amikacin and none to gentamicin. The most prevalent resistance pattern was ApCmSmTc (28%). Clinical isolates demonstrating multiple resistance were found to harbour a large transmissible plasmid of 45-75 MDa while isolates without multiple resistance did not. Two large virulence plasmids of 123 and 110 MDa were found in 12 strains of S. flexneri and 4 strains of S. sonnei phase I. Small plasmids of 4.5, 4.2, 3.5, 2.8, 2.5. 2.0 and 1.5 MDa were also present in all strains. These small plasmids were species specific and can be used as marker plasmids to identify species.

Newborn screening for biotinidase deficiency: pilot study and follow-up of identified cases

Biotinidase deficiency is an inborn error of biotin recycling that can result in an organic aciduria and developmental delay, seizures, alopecia, hypotonia and hearing loss. Early presymptomatic biotin treatment may prevent these complications and, on that basis, newborn screening for the disorder has been developed. In Massachusetts we conducted a one-year pilot study of newborn screening for biotinidase deficiency. Among 99,398 screened neonates, we identified three with profound biotinidase deficiency (1:33,000) and seven with partial deficiency (1:14,000). None of the infants had biochemical or clinical complications when evaluated. The three with profound deficiency were begun on biotin therapy and have thrived. Those with partial deficiency have received no therapy and have had normal growth and development. Transient biotinidase deficiency was overrepresented among low birth weight infants, as expected. Just as this pilot study ended, an infant in a neighboring state was diagnosed with biotinidase deficiency after coming to attention because of seizures, developmental delay and hearing loss. His newborn blood specimen retrieved from storage gave no activity on biotinidase screening. Newborn screening for biotinidase deficiency is effective in identifying cases and probably is of value in preventing irreversible complications from this disorder in at least some of the identified infants.

Detection of Phenylketonuria in the Very Early Newborn Blood Specimen

Early hospital discharge of newborns is leading to collection of the newborn screening blood specimen during the first day of life in increasing numbers of newborns. There is concern that neonates with phenylketonuria who are tested this early may be missed. To examine this question, the authors screened specimens collected during the first 24 hours of life from 23 neonates at risk for hyperphenylalaninemia. The blood phenylalanine level in each of the 6 neonates with phenylketonuria and a seventh with mild hyperphenylalaninemia was greater than 2 mg/dL as early as 4 hours of age and 6 mg/dL or greater by 24 hours of age. A newborn screening phenylalanine cutoff level of 2 mg/dL would have identified all of these neonates within the first 24 hours of life, but a cutoff level of 4 mg/dL would have missed 2 of the 6 with phenylketonuria before 24 hours of life. Newborn screening programs should adopt a blood phenylalanine level of 2 mg/dL as the cutoff for suspicion of phenylketonuria and request for a second specimen. Breast-fed affected neonates had higher early blood phenylalanine elevations than formula-fed neonates, perhaps reflecting the higher protein (phenylalanine) content of colostrum.

Comparative study of nine Bothrops snake venoms from adult female snakes and their offspring

Venoms of seven different Bothrops species and three subspecies ( B. alternatus, B. cotiara, B. erythromelas, B. jararaca, B. jararacussu, B. moojeni, B. neuwiedi paranaensis, B.n. pauloensis and B.n. urutu) obtained from individual mothers and their young were investigated. Biometrics of snakes and protein content, toxicity ( ld 50), SDS-PAGE, proteolytic and clotting activities of venoms were estimated. Comparison of venoms from female snakes and their respective newborn offspring were variable in protein content, toxicity, fibrinolytic/amidolytic/thrombin-like activities and in venom yield in relation to snake length. B.n. paranaensis and B.n. pauloensis possessed the most toxic venoms. Caseinolytic activity of all venoms from female snakes and procoagulant activity of their offspring were consistently high. Venoms of B. erythromelas mother and offspring had no amidolytic activity and the highest levels of factor X and prothrombin activators without thrombin-like action. In contrast, the venom of newborn B. cotiara possessed the highest thrombin-like activity whereas a B. jararacussu adult female did not possess any procoagulant activity. An extremely high procoagulant activity of the venom of newborn Bothrops specimens was demonstrated.

Biochemical and pharmacological similarities between the venoms of newborn Crotalus durissus durissus and adult Crotalus durissus terrificus rattlesnakes

J. M. Gutiérrez, M. C. dos Santos, M. de Fatima Furtado and G. Rojas. Biochemical and pharmacological similarities between the venoms of newborn Crotalus durissus durissus and adult Crotalus durissus terrificus rattlesnakes. Toxicon 29, 1273–1277, 1991. A comparative study was performed with the venoms of newborn Crotalus durissus durissus, adult Crotalus durissus terrificus and adult Crotalus durissus durissus snakes. Venom of newborn specimens of C. d. durissus is very similar to that of adult specimens of C. d. terrificus, since they have strong lethal and myotoxic activities, and weak proteolytic, hemorrhagic and edema-forming effects, in contrast to venom of adult specimens of C. d. durissus. In addition, the two former venoms have high amounts of the neurotoxic complex crotoxin, whereas venom from adult C. d. durissus has a low concentration of crotoxin. Electrophoretic analysis corroborates the strong similarities between the former two venoms. It is concluded that venom of newborn C. d. durissus contains high concentrations of crotoxin and low amounts of hemorrhagic and proteolytic components, and that a drastic ontogenetic change takes place in the venom composition of this subspecies.

128 BINDING OF CLONED S-FIMBRIATEO E.COLI TO HUMAN BUCCAL EPITHELIAL CELLS -INCREASED ABILITY OF NEONATAL SALIVA TO INTERFERE WITH BACTERIAL ADHESION COMPARED TO ADULT SALIVA

A common feature of E.Coli strains causing sepsis and meningitis in the newborn period are K1 capsules and S-fimbriae. Because adhesion of pathogenic microorganisms to mucosal surfaces is a fundamental prerequisite for infection we investigated adhesion of S-fimbriated E.Coli to buccal epithelial cells obtained from newborn babies. FITC-labelled E.Coli (strain HB101 pANN 801-4) carrying plasmid pANN 801-4 encoding for S-fimbriae were incubated with mucosal epithelial cells. Analysis by fluorescence mikroskopy showed that bacteria had been bound to 75 - 90% of epithelial cells. This binding was specifically mediated by glycoproteins containing neuraminic acid which could be shown by inhibition experiments using fetuin, α1-acid glykoprotein, methyl-α-D-mannoside and sialic acid. Using this test system the inhibitory activity of saliva on bacterial adhesion was analyzed. The capacity of newborn saliva to inhibit bacterial adhesion was much higher than that of adult saliva: newborn saliva could be diluted 4 - 5 fold to show inhibitory activity equal to adult saliva. Chemical analysis of newborn saliva specimens revealed a 4-5 fold increased total content of sialic acid (mostly protein bound). Using Western blot analysis of newborn and adult saliva we identified sialoglycoprotein bands with relative molecular masses > 200 KD reactive with wheat germ agglutinin which, accordingly, have to be classified as mucins. These data suggest that saliva mucins could represent a major defense mechanism against bacterial infections at a stage of ontogeny were the secretory IgA system is not yet developed.

Screening for congenital hypothyroidism in France

Misdiagnosed cases of congenital-hypothyroidism (CH) during the first 9 years of the French screening program were analysed. A total of 50 cases were missed (3% of total diagnosed) which represents a severe failure of the system. Failures were caused by technical errors of sample collection or TSH assay (n = 27) or due to normal TSH (n = 22) or T4 (n = 1) concentrations in the newborn blood specimens. We conclude that screening methods should be improved and that physicians should remain alert to clinical signs of hypothyroidism.

Ontogenetic changes in the venom of the snake Lachesis muta stenophrys (bushmaster) from Costa Rica

J. M. Gutiérrez, C. Avila, Z. Camacho and B. Lomonte. Ontogenetic changes in the venom of the snake Lachesis muta stenophrys (bushmaster) from Costa Rica. Toxicon 28, 419–426, 1990.—A comparative study was performed on some enzymatic and toxic activities of venoms collected from newborn, one-year old, two-years old and adult (more than five-years old) specimens of Lachesis muta stenophrys. There was an increase in lethal, hemorrhagic, edema-forming, myotoxic, proteolytic and phospholipase A 2 activities of venoms as snakes aged. The venom of newborn specimens was almost devoid of toxicity. On the other hand, venom from newborn specimens showed the highest coagulant effect on human plasma. Electrophoretic and immunochemical results demonstrated conspicuous differences between venoms of different ages. Observations on the feeding behavior indicated that specimens of L. muta of different ages displayed a similar pattern, characterized by rapid strike and bite, holding the prey until they stopped their movements and swallowing them afterwards. It is concluded that venom of newborn L. muta has very low toxic and proteolytic activities and that it undergoes conspicuous changes during the first year of life.

Developmental changes in the expression of genes involved in cholesterol biosynthesis and lipid transport in human and rat fetal and neonatal livers

Cloned cDNAs encoding a number of enzymes involved in cholesterol biosynthesis as well as extracellular and intracellular lipid transport were used to compare the developmental maturation of these biologic functions in the fetal and neonatal rat and human liver. The results of RNA blot hybridization analyses indicate that steady-state levels of rat HMG-CoA synthase, HMG-CoA reductase and prenyl transferase mRNAs are highest in late fetal life and undergo precipitous (up to 80-fold) co-ordinate reductions immediately after parturition. These changes reflect the ability of the fetal rat liver to produce large quantities of cholesterol as well as the repression of this function during the suckling period in response to exogenous dietary cholesterol. Striking co-ordinate patterns of HMG-CoA synthase, reductase and prenyl-transferase mRNA accumulation were also observed in four extrahepatic rat tissues (brain, lung, intestine and kidney) during the perinatal period. The concentrations of all three mRNAs in the 8-week-old human fetal liver are similar to those observed throughout subsequent intrauterine development with less than 2-fold changes noted between the 8th through 25th weeks of gestation. Analysis of the levels of human apo AI, apo AII, apo B and liver fatty acid binding protein mRNAs during this period and in newborn liver specimens also indicated less than 2-3-fold changes. These observations suggest that the 8-week human liver has achieved a high degree of biochemical differentiation with respect to functions involved in lipid metabolism/transport which may be comparable to that present in 19-21 day fetal rat liver. Further analysis of human and rat fetal liver RNAs using cloned cDNAs should permit construction of a developmental time scale correlating hepatic biochemical differentiation to be constructed between these two mammalian species.

Alternative Methods for Screening

Alternative methods (Fig 1) are already available for screening newborns for hemoglobinopathies. When choosing among the methods, one should remember three aims: (1) to identify Hb S; (2) to detect when Hb A is absent, suggestive of an S/S homozygote or a double heterozygote for S/β°-thalassemia or for S/C or S/another β-globin variant; and (3) to screen for other potentially pathologic states. (Double heterozygosity for S/β+-thalassemia is also important to detect, for example.) Detection of β-thalassemia major by newborn screening would be useful but is not yet reliable. SPECIMENS Blood Both liquid (anticoagulated) blood and dried blood spots have been used. Liquid blood is easier to hemolyze, but dried blood spots are much easier to mail and store. Dried blood spots are already used in most states to screen for other disorders. Age In most states, a newborn capillary blood sample is obtained by heel puncture before the baby leaves the hospital to screen for phenylketonuria (and often for other disorders such as hypothyroidism). Cord blood, however, can be obtained in larger volume and is less likely to be contaminated by transfusion but more likely to be contaminated by maternal blood. I prefer the newborn specimen because of the advantages of coordinating screening programs both for thorough population coverage and for economic savings at several levels. In a coordinated screening program for multiple disorders, hemoglobinopathy screening may help in recognizing specimens from infants in whom a transfusion has taken place but the time the specimen was taken for screening has not been noted.