ABSTRACT
Prevalence of alpha gene triplication or deletion in beta-thalassemia carriers was studied in 109 unrelated individuals in Rosario, Argentina. In different populations -alpha(3.7) allele presents a higher prevalence than alphaalphaalpha(anti3.7); thus, alpha-thalassemia associated with beta-thalassemia is more frequently observed. Nevertheless, this event was detected in only one case (0.9%), while the association with alpha triplication was present in two subjects (1.8%).
Subject(s)
Gene Deletion , Gene Duplication , Globins/genetics , alpha-Thalassemia/genetics , Adult , Alleles , Argentina/epidemiology , Blood Cell Count , Child , Female , Hemoglobins/metabolism , Heterozygote , Humans , Infant , Male , Prevalence , alpha-Thalassemia/blood , alpha-Thalassemia/epidemiologyABSTRACT
A novel nondeletional alpha-thalassemia mutation that affects RNA processing, changing the alpha2 IVS-II-142 splice acceptor consensus sequence from AG to AA, has been detected in an Argentinian patient with Hb H disease and her daughter.
Subject(s)
Globins/genetics , Point Mutation , RNA Splice Sites/genetics , alpha-Thalassemia/genetics , Adult , Aged , Argentina , Base Sequence , Child , Family Health , Female , Hematologic Tests , Humans , Male , PhenotypeABSTRACT
BACKGROUND AND OBJECTIVES: a-globin cluster polymorphisms are obtained with specific restriction enzymes (Xba I, Eco RI, Sac I, Apa I, Bgl II, etc) that can also have implications for genetic analysis. DESIGN AND AND METHODS: We studied three unrelated patients; one from Argentina, one from Spain and one from Australia but of Polish origin. Genomic DNA was digested with several different restriction enzymes and probes, amplified and sequenced with an ABI Prism 310 sequencer. RESULTS: In the three patients an abnormal 26 kb band appeared when they were studied with restriction enzyme Bgl II and z probe. A fragment of 944 bp was amplified with primers that cover from -280 to +714 bp of the recognition sequence of Bgl II enzyme (AGATCT) localized 5' from pseudogene z1. After digestion of this PCR product with Bgl II, two fragments of 714 and 280 bp were produced in normal controls, whereas in patient #1 the PCR fragment was undigested and in patients 2 and 3 both undigested and digested fragments were observed. Sequencing of the PCR fragment showed that in all three patients it was the same polymorphism (G->A) at nucleotide 153171 of the 16 p sequence found in the Bgl II recognition site that changed to AAATCT. INTERPRETATION AND CONCLUSIONS: We describe a new polymorphism in the yz1 first exon Bgl II restriction site (G->A). The polymorphism is associated in cis with haplotype -a3.7. The fragment obtained by PCR enabled us to corroborate the presence of the polymorphism quickly without having to use complicated sequencing techniques.
Subject(s)
Globins/genetics , Adult , Base Sequence , Blotting, Southern , DNA Mutational Analysis , Deoxyribonucleases, Type II Site-Specific/metabolism , Family Health , Female , Humans , Male , Molecular Sequence Data , Polymorphism, Genetic , alpha-Thalassemia/geneticsSubject(s)
Hemoglobins, Abnormal/genetics , Homozygote , Adult , Anemia, Hemolytic/genetics , Argentina , DNA Mutational Analysis , Humans , Italy/ethnology , MaleSubject(s)
Mutation/genetics , beta-Thalassemia/epidemiology , beta-Thalassemia/genetics , Amino Acid Substitution , Argentina/epidemiology , DNA Mutational Analysis , Family Health , Gene Frequency , Greece/ethnology , Heterozygote , Humans , Italy/ethnology , Spain/ethnology , beta-Thalassemia/ethnologyABSTRACT
The present work describes modification of a widely used salting-out procedure to rapidly extract DNA suitable for PCR, using the ARMS method to amplify a target sequence in the beta-globin gene. The salting-out DNA extraction procedure did not completely remove or decrease the presence of inhibitors to PCR in a considerable number of cord blood samples. By introducing a simple phenol/chloroform step, before ethanol precipitation of the nucleic acid, to certain samples, we were able to eliminate or substantially reduce the presence of inhibitors to PCR without having to re-extract the samples.
Subject(s)
Blood Cells/chemistry , DNA/blood , Fetal Blood/cytology , Globins/genetics , Chemical Precipitation , Chloroform , Electrophoresis, Agar Gel , Ethanol , Ethidium , Humans , Indicators and Reagents , Infant, Newborn , Phenol , Polymerase Chain Reaction , SpectrophotometrySubject(s)
Hemoglobinopathies/diagnosis , Neonatal Screening/methods , Argentina , Humans , Infant, NewbornABSTRACT
Hematological parameters in newborn umbilical cord blood samples (n = 476), collected at the Hospital Provincial del Centenario, Rosario, were studied. They were divided into 3 groups: (I) full term newborns with weight according to gestational age; (II) low weight and normal gestational age; (III) preterm newborns. The results were as follows: group (I) Hb: 15.5 +/- 1.1 g/dl; RBC; 4.66 +/- 0.33 x 10(12)/l; PCV: 49% +/- 4.3%, MCV 105.1 +/- 5.3 fl; MHC: 33.2 +/- 1.2 pg. Decreased Hb concentration (p < 0.05) and increased MCV (p < 0.01) were observed in preterm newborns in comparison with normal ones, and a slight PCV increase and RBC values in low weight newborns compared to the control group (p < 0.05). Erythrocyte morphology was normal as well as reticulocyte values in these samples. The electrophoretic pattern was (FA) with the following Hb F values 66.3 +/- 6.8%, and Hb A2 0.45 +/- 0.3% in group (I), with a significant increase of Hb F in 30-35 weeks preterm newborns. Group (I) values are considered as normal hematological parameters in newborns in our country, whereas MCV < 94.7 fl is considered as a neonatal microcytosis marker, consequently an alert to investigate alpha-thalassemia. There was no influence on Hb concentration due to maternal smoking habit. The present work could be of relevance for our region since up to the present time there are no similar records.
