[Show abstract][Hide abstract] ABSTRACT: Between 1983 and 2008, prenatal diagnostic procedures for identifying hemoglobinopathies were performed in 947 at-risk fetuses. Seventy-six percent of the fetuses were at risk for β-thalassemia major and 16% for sickle cell anemia; only a small percentage (7%) were at risk for compound heterozygosity of β-thalassemia and an abnormal hemoglobin of the β chain. The results of the study showed that β gene mutations in hemoglobinopathies have a very broad spectrum. Seven hundred and thirty of the 947 fetuses examined using the DNA technique showed 88 different combinations of 27 different mutations. Although the number of fetuses evaluated was far below the desired target, the termination of 261 affected fetuses provided both psychological and economic relief for the parents and was economically beneficial for the country in the long term.
Pediatric Hematology and Oncology 02/2011; 28(1):51-5. · 0.90 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The testing program of cord blood samples for hemoglobin (Hb) abnormalities, presently conducted in a few centers of Turkish Universities, sometimes detects rare variants which may or may not affect the health of the newborn. One example to be described here is O-Padova which has been observed once before (1). The variant was detected in the blood of a newborn girl by starch gel electrophoresis at pH 9.0 (2); the mobility of the variant (presumably α2Xγ) was slightly slower than that of Hb C (or α2β26 Glu→Lys) (Fig. 1). Red cell lysates from the father and a 2-year-old brother contained a different Hb component with a mobility distinctly faster than that of Hb A2 or of Hb C; a minute quantity of a similar component (presumably α2X2) was also present in the cord blood red cell lysate of Baby E (Fig. 1). The baby was retested when 40 days old; her hematological values and those of her father and brother were normal (Table I). Quantitation by cation exchange high performance liquid chromatography (HPLC) (3) gave total Hb X values of 15.4% for the baby (Hb X + Hb Fx), 18.3% for the father (Hb X + Hb X2), and 12.8% for the brother (Hb X + Hb X2) (see also Table I).
[Show abstract][Hide abstract] ABSTRACT: We recently examined a 16-year-old high school student who participated in a survey for Hemoglobinopathies in an Anatolian city in Turkey. Analysis if his hemoglobin (Hb) showed the presence of an electrophoretically slow-moving variant (at pH 8.6, about as Hb S) which, upon further examination, was also seen in his father, one brother, and one sister.
[Show abstract][Hide abstract] ABSTRACT: A 30-year-old female who is homozygous for a Hb E-like abnormal hemoglobin and her immediate relatives were studied. Clinical examination of the proband revealed no abnormality. Routine hematological analysis showed that her hemoglobin level was 12 g/dL, MCV 82 fL, MCH 28 pg, RDW 15%. DNA sequence analysis indicated the presence of a G → A substitution at codon 22 corresponding to an abnormal hemoglobin, namely Hb E-Saskatoon [β22(B4)Glu → Lys (GAA → AAA)]. Absence of any abnormalities in clinical and routine hematological investigations of the homozygous patient indicated that the phenotypical expression of the Hb E-Saskatoon is very mild. Using a reverse transcription-polymerase chain reaction technique, the α/β and βX/βA-mRNA (X = Hb E-Saskatoon) ratios were determined. Normal α/β and βX/βA-mRNA ratios were found in the homozygous patient and in all heterozygotes, indicating that the respective mutation did not alter the stability of the mRNA. FokI restriction enzyme analysis of the polymerase chain reaction products obtained from the genomic DNA and/or β-globin mRNA made it possible for rapid diagnosis of Hb E-Saskatoon, and for its differentiation from Hb E [β26(B8)Glu → Lys (GAG → AAG)]. Analysis of the restriction fragment length polymorphism (RFLP) in the β-globin gene complex of the index patient and of another unrelated family with a compound heterozygosity for Hb E-Saskatoon and β-thalassemia revealed that the Hb E-Saskatoon mutation shared a common allele.
[Show abstract][Hide abstract] ABSTRACT: A review is presented of the various β-thalassemia alleles observed in nearly 191 patients with β-thalassemia major and their 182 heterozygous relatives. Determination was by gene amplification and dot-blot hybridization with synthetic probes, specific for 27 different mutations. Eighteen mutations have been observed; six of these acount for nearly 83% of all thalassemia abnormalities (Table I). A new mutation, i.e. a G C mutation at the acceptor splice site of IVS-I, was found in one teenager who was homozygous for this disease. the high consanguinity among the families was considered the main reason for the high number of patients with a homozygosity for the IVS-I-110 (G A) mutation. Combinations of different mutations were present in many patients; some were mildly affected because of the specific mutation present on one chromosome. Combinations of classical β-thalassemia and an abnormal hemoglobin mainly concerned Hb S. Hbs Knossos and Lepore were rare occurrences. A comparison of hematological data for adults with heterozygosities for some of the common alleles confirmed the low Hb A2 values in IVS-I-6 (T C) heterozygotes and the high Hb F values for codon 8 (-AA), IVS-II-1 (G A), and IVS-I-1 (G A) heterozygotes.
[Show abstract][Hide abstract] ABSTRACT: Globin gene mapping analyses of DNA from numerous Black babies, and from newborns from Sardinia, Sicily, Turkey, and Spain have identified the following A high incidence of α-thalassemia-2 heterozygotes among Black babies with less than 1% Hb Bart's at birth and a high incidence of α-thalassemia-2 among Sardinians, but not among Sicilian, Turkish, and Spanish babies. A relatively high incidence of ζ-thalassemia was present among Black babies only, while triplicated ζ was seen in four of the five populations. Two Black babies were each found to have a different θl deletion; two Sardinian babies had a newly discovered β 2.5 kb deletion between ζ and ψζ; four babies had the rare Bgl II polymorphism between ψζ and ψα; and one Black baby lacked the Eco RI site 3’ to ζ Quantitation of the ζ chain by reversed phase high performance liquid chromatography showed that two-thirds of the babies with four α genes (αα/αα) had levels between 0.1 and 1.0%, while nearly 90% of the babies with -α/αα had similar levels (averaging 0.2% for αα/αα 0.35% for -α/αα 0.75% for -α/-α). Additional data indicated that the occurrence and level of ζ are related to the level of β, i.e. the gestational age. The presence of a ζ triplication did not affect the level of ζ in cord blood. The extensive search for γ-globin gene anomalies resulted in the discovery of a chromosome with five γ genes, γ-Thalassemia was rare in all populations, while the -Gγ-Gγ- gene arrangement was mainly observed among Black babies; this arrangement is primarily responsible for high Gγ levels in cord blood samples. The strong correlation between the presence or absence of a C→T mutation at position -158 (measured in Xmn I digests) and the level of Gγ was confirmed for adult blood samples. A search for possible anomalies in the -δ-β- region through gene mapping with Eco RV gave negative results except for the discovery of a polymorphic site 5’ to δ in one of the 371 Black babies tested.
[Show abstract][Hide abstract] ABSTRACT: Two homozygous δ0 β0-thalassemia patients, one with the GγAγ type and the other with the Gγ type, and their heterozygous parents are described. Red cell indices among the heterozygotes with the GγAγ type of δ0β0-thalassemia were markedly different from those in heterozygotes with the Gγ type. However, the imbalance in in vitro hemoglobin synthesis was quite similar in the two heterozygous conditions. The same was observed for the homozygous patients; the in vitro chain synthesis was severely imbalanced as seen in β-thalassemia major. The clinical and some of the hematological findings were milder in the Gγ-δ0 β0-thalassemia homozygote than in the GγAγ - δ0 β0-thalassemia homozygote. The death of a sibling of the Gγ - δ0 β0-thalassemia homozygote with a diagnosis of thalassemia major suggests that both types of δ0 β0 -thalassemia could follow a severe clinical and hematological course. The discovery of the Gγ type of δ0 β0-thalassemia in a Turkish child shows that two types of δ0 β0 - thalassemia can be found in that country. Differentiation between the two types can only be made through structural analyses of Hb F.
[Show abstract][Hide abstract] ABSTRACT: A case control study was conducted to test the hypothesis that plasminogen activator inhibitor type-1 (PAI-1) 4G/5G gene polymorphism confers an increased risk for myocardial infarction (MI) in patients with known coronary atherosclerosis.
One hundred fifty-six consecutive patients who presented with acute MI and 111 stable coronary artery disease (SCAD) patients with documented critical coronary artery stenoses were prospectively enrolled. PAI-1 4G/5G gene polymorphism and conventional atherosclerotic risk factors were studied in all patients. PAI-1 4G/5G gene polymorphism was studied in another 281 healthy blood bank donors.
The frequency 4G4G genotype was significantly higher in the MI group as compared to SCAD group (32.7% vs. 15.3%, P = 0.001) while it was not statistically significant between MI and healthy control groups (32.7% vs. 26.0%, P = 0.136). Comparing with healthy controls SCAD group had significantly lower frequency of 4G4G genotype (P = 0.024). In comparison with SCAD group PAI-1 4G/4G genotype, male sex and smoking habits favored to MI in univariate analysis with a P value of less than 0.2. These variables were included in multivariate regression model to estimate the associated risk for MI. PAI-1 4G/4G genotype was the only independent variable (OR 2.67, 95%CI 1.43-4.96, P = 0.002) associated with MI in this regression model. Comparing with healthy control group 4G4G genotype was not associated with MI (OR 1.38, 95%CI 0.90-2.12). However, presence of 4G4G genotype had a protective effect against development of SCAD (OR 0.52, 96%CI 0.29-0.92).
Compared to patients with critical coronary stenoses, PAI-1 4G/4G genotype was found to be an independent predictor for development of MI in this population. PAI-1 4G4G genotype have a protective effect against development of high grade stable coronary stenoses.
Journal of Thrombosis and Thrombolysis 09/2007; 26(3):211-7. · 1.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Defects in erythrocyte ankyrin are the most common cause of typical, dominant hereditary spherocytosis (HS). Detection of ankyrin gene mutations has been complicated by allelic heterogeneity, large gene size, frequent de novo mutations, and associated mRNA instability. Using denaturing high-performance liquid chromatography (DHPLC)-based mutation detection, a mutation in the splice acceptor of exon 17 was discovered in a Turkish family. Reticulocyte RNA and functional minigene splicing assays in heterologous cells revealed that this mutation was associated with a complex pattern of aberrant splicing, suggesting that removal of intron 16 is important for ordered ankyrin mRNA splicing. As predicted by clinical, laboratory, and biochemical studies, the parents were heterozygous and the proband was homozygous for this mutation. These data indicate that DHPLC offers a highly sensitive, economic, and rapid method for mutation detection and, unlike previously suggested, homozygosity for a mutation associated with dominant ankyrin-linked HS may be compatible with life.
[Show abstract][Hide abstract] ABSTRACT: Early detection and therapy of haematological abnormalities and/or diseases may improve the prognosis of metabolic disorders. Accordingly, we aimed to evaluate the frequency and types of haematological abnormalities in children[-31pc] with various inherited metabolic disorders. The study group comprised 46 children with metabolic disorders who were followed at the Pediatric Metabolism Unit and were referred to the Pediatric Hematology Unit for evaluation of anaemia between June 2000 and 2005. The mean age of the children was 55.2 +/- 64.8 months at haematological evaluation (range 1 month-18 years, median 22.0 months); 16 were female and 30 were male. Of these 46 patients with anaemia, 25 of (54.3%) had anaemia of chronic disease (ACD), 9 (19.6%) had iron-deficiency anaemia (IDA), 7 (15.2%) had megaloblastic anaemia due to vitamin B(12) deficiency, 3 (6.5%) had chronic haemolytic anaemia, 2 (4.3%) had autoimmune haemolytic anaemia, 1 had beta-thalassaemia major, and 1 had hereditary spherocytosis. In addition to the anaemia, bicytopenia or pancytopenia was found in 8 of 46 children (17.4%). The study indicated that in organic acidaemias including methylmalonic acidaemia, propionic acidaemia, isovaleric acidaemia, and argininosuccinic acidaemia, the majority of patients had ACD (75%), which was followed by vitamin B(12) deficiency anaemia and IDA (p < 0.001). In PKU, both nutritional anaemias and ACD were present at about same frequency: 46.7% and 40%, respectively (p > 0.05). This study suggested that congenital anaemias such as hereditary spherocytosis or thalassaemias should be kept in mind as a coexisting haematological diseases in young patients with inborn errors of metabolism. In conclusion, ACD and nutritional anaemias are the most prevalent anaemias seen in patients with inborn errors of metabolism. Early detection of the disease, early administration of specific diet, and close monitoring of the patients are very important factors to prevent the development of haematological diseases in patients with inborn errors of metabolism.
[Show abstract][Hide abstract] ABSTRACT: Current tests for evaluation of vitamin B(12) absorption are problematic because they involve the use of radioactively labeled vitamin B(12). We describe a vitamin B(12) absorption test that circumvents this problem.
We measured cobalamin or transcobalamin saturated with cobalamin (holo-TC) 24 h after three 9-microg doses of vitamin B(12) given orally at 6-h intervals. We studied 17 patients with inherited malabsorption of vitamin B(12) attributable to Imerslund-Grasbeck syndrome (n = 13) or intrinsic factor deficiency (n = 4), their obligate heterozygous biological parents (n = 19), and healthy controls (n = 44).
In the patients, the median (range) change of holo-TC after the B(12) load was not significant [1 (-42 to 5) pmol/L], nor was the change of cobalamin [-3 (-32 to 22) pmol/L], consistent with a lack of measurable active or passive absorption. In controls, however, the median (range) increases of holo-TC and cobalamin were 26 (-6 to 63) pmol/L and 41 (-37 to 109) pmol/L, respectively. Similarly, the parents showed increases of 23 (-2 to 47) pmol/L and 27 (-15 to 94) pmol/L. The mean areas under the ROC curves (95% confidence intervals) were 0.97 (0.93-1.0) for holo-TC and 0.87 (0.79-0.94) for cobalamin, distinguishing patients from controls. At a cutoff of 6 pmol/L for holo-TC, the diagnostic sensitivity (95% confidence interval) was 100 (81-100)%, and the diagnostic specificity was 92 (82-97)%.
Measurement of holo-TC after administration of vitamin B(12) is a promising approach for evaluating vitamin B(12) absorption.
[Show abstract][Hide abstract] ABSTRACT: Purpura fulminans (PF) is a severe disorder of acute onset with high morbidity and mortality. In children, this rapidly progressive illness is usually associated with severe bacterial or viral infections. However, some other conditions may participate in the development of PF. Our objective was to investigate the underlying and associated disorders and the outcomes of the disease in 16 children, 7 males and 9 females ranging in age from 3.5 months to 12 years (median age, 2 years). Thirteen of the 16 children (81%) were 4 years of age or younger. The remaining 3 patients were 9, 10, and 12 years of age. Among these 13 infants and small children, 7 (43%) had infection, 2 infants had congenital cardiac disorders necessitating minor or major surgical intervention, and 1 infant and 3 children had different miscellaneous disorders. The factor V G1691A mutation was present in six of the 13 small children (46%). None of the 3 older children carried the mutation. Six (37.5%) of the 16 patients had protein C deficiencies, and 9 (56%) had protein S deficiencies. These deficiencies, except one for protein S, were acquired. Ten patients except two who were diagnosed at this center were treated with fresh frozen plasma. They were also given heparin. Nine (69%) of the 13 children 4 years of age or younger and one of the older children (33%) required amputation. Five of the six patients (83%) who had factor V G1691A mutation, and who also exhibited severe infection, required amputation. This study suggests that an age of 4 years or less is a risk factor for the development of PF during severe infections, especially in the presence of factor V G1691A mutation and congenital heart disease, necessitating major or minor surgical interventions. This study also shows that the amputation rate in 10 patients, after excluding the patients who had been referred to our center after development of sequelae, was 60%. The survival rate among these 10 patients may indicate that, with the treatment protocol, PF need not be regarded as a lethal disease any more. It is also suggested that effective immunization programs and better health care have probably resulted in some changes in the etiological profile of PF.
American Journal of Hematology 10/2005; 80(1):20-5. · 4.00 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To investigate the morphology and function of platelets in nephropathic cystinosis (NC).
Seven patients (mean age, 6.5 years; SD, 20 months) with NC were investigated. Their platelets were examined by transmission electron microscopy (TEM) and the characteristics of the dense granules (DGs) were determined by mepacrine labelling and the uranaffin reaction. Bleeding time, turbidometric aggregation, and luminescence aggregation were studied and intraplatelet cystine was measured.
Increased intraplatelet cystine, primary and secondary aggregation defects, and the absence of ATP release were demonstrated. TEM revealed DGs of various shapes and sizes and lamellary or amorphous cytoplasmic inclusions. Viscous material had been released into the vacuolar spaces and enlarged open canalicular system. Mepacrine labelling revealed that the numbers of DGs/platelet were comparable between the patients and the controls (mean, 2.9 (SD, 0.22) v 3.32 (0.18); p = 0.34). The uranaffin reaction revealed that the numbers of type 1, 3, and 4 DGs were comparable between the patients and the controls, but that there were fewer type 2 DGs in the patients (mean, 8.5 (SD, 1.95) v 17.22 (1.58); p = 0.01). TEM for platelet aggregation revealed a lack of induction and/or defective execution and/or delayed transmission. The patients' intraplatelet cystine concentrations were higher than the controls (mean, 1.56 (SD, 0.84) v 0.08 (0.01) nmol/mg protein; p = 0.009).
This is the first report to demonstrate raised intraplatelet cystine, abnormal platelet ultrastructural findings, and defective aggregation in NC.
Journal of Clinical Pathology 10/2005; 58(9):939-45. · 2.44 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hereditary juvenile megaloblastic anemia due to vitamin B12 (cobalamin) deficiency is caused by intestinal malabsorption of cobalamin. In Imerslund-Grasbeck syndrome (IGS), cobalamin absorption is completely abolished and not corrected by the administration of intrinsic factor (IF); if untreated, the disease is fatal. Biallelic mutations either in the cubilin (CUBN) or amnionless (AMN) gene cause IGS. In a series of families clinically diagnosed with likely IGS, at least six displayed no evidence of mutations in CUBN or AMN. A genome-wide search for linkage followed by mutational analysis of candidate genes was performed in five of these families. A region in chromosome 11 showed evidence of linkage in four families. The gastric IF (GIF) gene located in this region harbored homozygous nonsense and missense mutations in these four families and in three additional families. The disease in these cases therefore should be classified as hereditary IF deficiency. Clinically, these patients resembled those with typical IGS; radiocobalamin absorption tests had been inconclusive regarding the nature of the defect. In the diagnosis of juvenile cobalamin deficiency, mutational analysis of the CUBN, AMN, and GIF genes provides a molecular characterization of the underlying defect and may be the diagnostic method of choice.
Proceedings of the National Academy of Sciences 04/2005; 102(11):4130-3. · 9.81 Impact Factor