广西地区104例泰国缺失型α-地中海贫血1的研究

目的:对广西地区的泰国缺失型α-地中海贫血1的血液学、基因型、临床表现及民族分布进行分析。方法:对门诊病人进行血常规、血红蛋白电泳及-地中海贫血基因分析,收集已确诊为泰国缺失型α-地中海贫血1患者的检测数据及临床资料,并用SPSS统计软件对以上数据进行统计分析。结果:共检出104例泰国缺失型α-地中海贫血1,其中71例基因型为--THAI/αα,17例基因型为--THAI/-α3.7,14例基因型为--THAI/αCSα,2例基因型为--THAI/αQSα。统计学分析:--THAI/αα杂合子和--SEA/αα杂合子的血常规结果比较没有统计学意义,P0.05;泰国型Hb H病(--THAI/-α3.7、--THAI/αCSα、--THAI/αCSα)和东南亚型Hb H病(--SEA/-α3.7、--SEA/αCSα)的血常规结果比较有统计学意义,P0.01;民族分布上,有67例为壮族,34例为汉族,其他民族3例。结论:泰国缺失型-地中海贫血1在广西有一定的发生率,在壮族人群多见;和东南亚缺失型Hb H病相比,泰国缺失型Hb H病出现临床症状的时间更早、贫血更严重。     

海口地区89例α-地中海贫血基因型的研究

为了探讨海口地区α-地中海贫血的基因型和发病情况,作者采用聚合酶链反应(polymerase chain re-action,PCR)技术进行α-地中海贫血基因分型的检测.结果显示,海口地区319例疑诊患者共检出α-地中海贫血为89例,阳性率达27.90%,共检出8种基因型:--SEA/αα(33例)、-α3.7/αα(18例)、-α3.7/-α3.7(3例)、-α4.2/αα(21例)、-α4.2/-α4.2(6例)、-α3.7/-α4.2(5例)、-α3.7/--SEA(1例)和-α4.2/--SEA(2例),以--SEA/αα东南亚缺失型为主.说明海口地区α-地中海贫血发生率较高,应加强地中海贫血的婚前、产前筛查和产前基因诊断等工作,以杜绝重型α-地中海贫血患儿的出生.     

夫妇双方同为地中海贫血时子女的患病风险

<正>问:地中海贫血基因检查的结果如下,男方:东南亚缺失型α地中海贫血-1,基因型(--/αα);女方:东南亚缺失型α地中海贫血-1复合-α4.2缺失型α地中海贫血-2,基因型(--/-α4.2)。这样婚配生出的小孩患地贫情况如何?答:地中海贫血(Thalassemia)是我国南方各省最常见、危害最大的遗传病,人群发生率高达10%以上,以广东、广西为主。     

地中海贫血的基因诊断

问:我在南方某市妇幼保健院做地中海贫血基因诊断检查,结果如下:α地中海贫血-1杂合子,基因型:--SEA/αα。(1)医生说是患有α型地中海贫血,     

HbQ-H病的α-珠蛋白基因分析

本文报道用限制性内切酶酶谱技术对我国江西一例HbQ-H病人进行α-珠蛋白基因分析,研究结果表明,本例HbQ-H病属左侧缺失型α-地中海贫血,患者的基因型为-α~Q/--。     

中国人α珠蛋白基因-α3.7缺失亚型的研究

-α3.7是中国人常见的缺失型α-地中海贫血-2。根据重组位点的不同,-α3.7可分为-α3.7Ⅰ型、-α3.7Ⅱ型和-α3.7Ⅲ型,并且亚型的种类和频率具有种族差异性。本研究在中国人群中用PCR基因分析方法检出具有α珠蛋白基因-α3.7缺失的患者56例,然后用ApalⅠ和BalⅠ限制性内切酶进行分型。 结果表明,在这56例具有-α3.7缺失的患者中,有54例是-α3.7Ⅰ型,有2例是-α3.7Ⅱ型,尚未发现-α3.7Ⅲ型。此结果丰富了我国α地贫基因型谱的资料。 Abstract:-α3.7 is a common deletional α-thalassemia-2 in China.According to different recombination sites,-α3.7 can be divided into -α3.7Ⅰ、-α3.7Ⅱand -α3.7Ⅲ.The frequency and population distribution of these -α3.7 are quite different.In this study,we detected 56 patients among Chinese population of -α3.7 defect in alpha globin gene by PCR method,then the PCR product was digested by the restriction enzyme ApalⅠand BalⅠ.The sub-typing result shows that in the 56 cases of -α3.7 defect,54 out of 56 is -α3.7Ⅰ,2 out of 56 is -α3.7Ⅱ and none of -α3.7Ⅲ is detected.This result enriches the data about the alpha thalassemia genotypes of Chinese people.     

血红蛋白G-Philadelphia复合α地中海贫血——化学结构和基因组织分析

在广西乐业县一壮族家庭中发现一慢速异常血红蛋白,其含量占携带者血红蛋白总量的1/3。对异常血红蛋白的化学结构分析和氨基酸组成及顺序测定的结果证实,该异常血红蛋白为HbG-Philadelphia(α68[E17]Asn→Lys)。用EcoR Ⅰ和Bgl Ⅱ限制性内切酶对先证者的α-珠蛋白基因组织进行分析,结果表明α~G突变基因顺式连锁着一个右侧缺失型(-3.7kb)α地中海贫血2基因,因此携带者基因型为α~G/αα。     

血液检验在贫血诊断与鉴别诊断中的价值分析

目的:分析血液检验在贫血诊断和鉴别诊断中的价值。方法:选取血常规检测的贫血患者122例,按照患者的贫血类型分为缺铁性贫血组和地中海贫血组,另选取健康成人作为对照组。对三组进行血细胞进行检测,对三组患者血液中的RDW、RBC/MCV、MCH、Hb、MCV、RBC指标的差异进行观察。结果:缺铁性贫血组患者的RBC、Hb指标低于地中海贫血组和对照组,而RDW高于其他两组,具有统计学意义,P0.05。地中海贫血组患者的RBC、RBC/MCV高于其他两组,有统计学意义,P0.05。缺铁性贫血组患者和地中海贫血组患者的MCH、MCV低于对照组,有统计学意义,P0.05。结论:血液检测中的RDW、RBC/MCV、MCH、Hb、MCV、RBC指标可以帮助贫血疾病的诊断,并且能够对不同类型的贫血进行鉴别,具有十分重要的意义。     

高效液相色谱技术在儿童血红蛋白病检查中的应用

目的:探讨高效液相色谱技术在儿童血红蛋白(Hb)病检查的意义,并时5356例检测结果进行分析.方法:采集5356例广东地区儿童EDTA-K2抗凝血2ml,采用HPLC方法测定各血红蛋白组分含量.结果:在5356例儿童中,检出血红蛋白病977例(18.24%),其中检出β地中海贫血673例(12.57%),α地中海贫血283例(5.28%),其中包括21例CS型HbH病(0.39%),α复合β地中海贫血8例(0.15%),HbE病8例(0.15%),HbQ病5例(0.09%).结论:广东地区儿童血红蛋白病的发生率高,应用HPLC技术加强对儿童血红蛋白(Hb)病进行筛查,早发现,早预防,指导合理婚配,对优生优育提高人口素质具有重要意义.     

在中国壮族家系中发现的一例-α~T/-α~Q复合β~0β~0珠蛋白基因型

本文报道在我国广西隆林壮族中发现一个罕見的HbQ复合α,β地中海贫血家系。先证者女,18岁,贫血面容,肝脾肿大。化学结构分析确证本Hb变异体为HbQ Thailand[α74(EF3)Asp→His]。血红蛋白组成以及α和β珠蛋白基因分析结果表明,先证者的珠蛋白基因型为-α~Q/-α~T复合β°/β°(IVSI-1G→T/Codon17A→T);先证者父的基因型为-‘α~Q/-复合β~O/β~A(IVSI-1G→T/β~A);先证母的基因型为-α~T/αα复合β~O/β~A(Codon17A→T/β~A)。     

Types of alpha+ thalassemia in Southeast Asia refugees

We have determined alpha+ deletional thalassemia among 143 Southeast Asia refugees (Cambodians, Laotians, and Vietnameses). Gene frequency of alpha+ deletional thalassemia in Vietnameses (0.035) was found lower than in Cambodians and Laotians (0.11). Bam H1 and Bg1 II analysis indicated that both rightward and leftward thalassemias are encountered, the -alpha 3,7 form is being by far more frequent than the -alpha 4.2 one. Only type I cross-over was found by Apa I digestion on -alpha 3.7 chromosomes. The Rsa I polymorphism, 5' to Z alpha 2 block, is associated with -alpha 3.7 type I haplotype and the site is present in 12 out of 23 chromosomes. All these data suggest at least three origins of alpha+-thalassemia in Cambodia and Laos.     

Molecular epidemiology and outcome of Helicobacter pylori infection in Thailand: a cultural cross roads

ABSTRACT Background. Thailand is at the cultural cross roads between East and South Asia. It has been suggested that this is also the region where the predominant Helicobacter pylori (H. pylori) genotype changes from East Asian to South Asian. Methods. We compared the molecular epidemiology and outcome of H. pylori infections among different ethnic groups in Thailand (Thai, Thai-Chinese and Chinese). H. pylori isolates were genotyped by polymerase chain reaction based on cagA, cag right end junction and vacA genotypes. Results. Ninety-eight isolates from 38 ethnic Thai, 20 ethnic Chinese and 40 Thai-Chinese were categorized into East Asian (45%), South/Central Asian (26%), Western (1%) or mixed type (29%). The East Asian genotype was the most common among Chinese (85%) and Thai-Chinese (55%) (p <.01 compared to ethnic Thai). The ethnicity of the mother among mixed Thai-Chinese marriages predicted the genotype of the child's H. pylori (e.g. when the mother was Chinese, 84% had East Asian type vs. 29% when the mother was Thai) (p <.001). Gastric cancer was common among ethnic Chinese with East Asian genotype (e.g. all Chinese with gastric cancer or peptic ulcer disease had East Asian genotype, whereas only 40% of Chinese with gastritis had this genotype). Conclusions. Immigration, intermarriage and the variety of H. pylori genotypes in Thailand suggest that Thailand is an ideal site for epidemiological studies attempting to relate H. pylori genotypes and host factors to outcome. Our data also support the hypothesis that the primary caretaker of the children is most likely the source of the infection.     

广西壮族人群EBI3 基因rs6613A/T, rs4905A/G多态性分布特点

目的:分析广西壮族人群EBI3基因rs6613A/T、rs4905A/G多态性分布特点。方法:采用单碱基延伸的PCR技术对168例广西壮族人群EBI3 rs6613 A/T和EBI3 rs4905A/G进行多态性检测,对比国际人类基因组计划(Hap Map)公布的中国北京人、日本人、非洲人和意大利人的SNP分型数据,分析5个人群rs6613 A/T、rs4905A/G位点的基因型和等位基因频率差异。结果:在广西壮族人群中,EBI3基因rs6613 A/T位点AT基因型最常见,约为49.4%;T等位基因频率最高,约为52.1%;rs4905A/G多态性位点AC基因型最常见,约为48.2%;C等位基因频率最高,约为50.9%。EBI3基因型及等位基因频率分布于性别无显著相关性(P0.05)。广西壮族人群EBI3基因rs6613A/T位点基因型和等位基因频率与北京人差异无统计学意义(P0.05),但与非洲人、日本人、意大利人差异具有统计学意义(P0.05);EB-13基因rs4905A/G位点基因型和等位基因频率与北京人和日本人差异无统计学意义(P0.05),但与非洲人和意大利人比较差异具有统计学意义(P0.01)。结论:EBI3基因rs6613 A/T和EB-13 rs4905A/G多态性位点基因型和等位基因在广西壮族人群中的分布频率与其他种族和地区人群相比存在差异,这种差异可能是导致某些疾病在不同人群发病率和临床表现存在差异的原因之一。     

Genotyping of alpha-thalassemia in microcytic hypochromic anemia patients from North India

Microcytic hypochromic anemia is a common condition in clinical practice and alpha-thalassemia has to be considered as a differential diagnosis. Molecular diagnosis of alpha-thalassemia is possible by polymerase chain reaction. The aim of this study was to evaluate the frequency of alpha-gene numbers in subjects with microcytosis. In total, 276 subjects with microcytic hypochromic anemia [MCV<80fl; MCH<27pg] were studied. These include 125 with thalassemia trait, 48 with thalassemia major, 26 with sickle-cell thalassemia, 15 with E beta-thalassemia, 40 with iron-deficiency anemia, 8 with another hemolytic anemia, and 14 patients with no definite diagnosis. Genotyping for -alpha3.7 deletion, -alpha4.2 deletion, Hb Constant Spring, and a-triplications was done with polymerase chain reaction. The overall frequency of -alpha3.7 deletion in 276 individuals is 12.7%. The calculated allele frequency for a-thalassemia is 0.09. The subgroup analysis showed that co-inheritance of a-deletion is more frequent with the sickle-cell mutation than in other groups. We were able to diagnose 1/3 of unexplained cases of microcytosis as a-thalassemia carriers. The a-gene mutation is quite common in the Indian subcontinent. Molecular genotyping of a-thalassemia helps to diagnose unexplained microcytosis, and thus prevents unnecessary iron supplementation.     

Prevalence of common α-thalassemia determinants in south Brazil: Importance for the diagnosis of microcytic anemia

Alpha thalassemia has not been systematically investigated in Brazil. In this study, 493 unrelated individuals from the southernmost Brazilian state of Rio Grande do Sul were screened for deletional forms of α-thalassemia. One hundred and one individuals had microcytic anemia (MCV < 80 fL) and a normal hemoglobin pattern (Hb A (2) < 3.5% and Hb F < 1%). The subjects were screened for - α(3.7) , - α(4.2) , - α(20.5) , - (SEA) and - (MED) deletions but only the - α(3.7) allele was detected. The - α(3.7) allele frequency in Brazilians of European and African ancestry was 0.02 and 0.12, respectively, whereas in individuals with microcytosis the frequency was 0.20. The prevalence of α-thalassemia was significantly higher in individuals with microcytosis than in healthy individuals (p = 0.001), regardless of their ethnic origin. There were also significant differences in the hematological parameters of individuals with - α(3.7) / αα, - α(3.7) /- α(3.7) and β-thalassemia trait compared to healthy subjects. These data suggest that α-thalassemia is an important cause of microcytosis and mild anemia in Brazilians.     

Hemoglobin Constant Spring among Southeast Asian Populations: Haplotypic Heterogeneities and Phylogenetic Analysis

Background

Hemoglobin Constant Spring (Hb CS) is an abnormal Hb caused by a mutation at the termination codon of α2-globin gene found commonly among Southeast Asian and Chinese people. Association of Hb CS with α°-thalassemia leads to a thalassemia intermedia syndrome commonly encountered in the region. We report chromosome background and addressed genetic origins of Hb CS observed in a large cohort of Hb CS among Southeast Asian populations.

Materials and Methods

A study was done on 102 Vietnamese (aged 15–49 year-old) and 40 Laotian (aged 18–39 year-old) subjects with Hb CS and results compared with 120 Hb CS genes in Thailand. Hematological parameters were recorded and Hb analysis was performed using capillary electrophoresis. Hb CS mutation and thalassemia genotypes were defined by DNA analysis. Six DNA polymorphisms within α-globin gene cluster including 5’Xba I, Bgl I, Inter-zeta HVR, AccI, RsaI and αPstI 3’, were determined using PCR-RFLP assay.

Results

Nine different genotypes of Hb CS were observed. In contrast to the Thai Hb CS alleles which are mostly linked to haplotype (+—S + + -), most of the Vietnamese and the Laotian Hb CS genes were associated with haplotype (+—M + + -), both of which are different from that of the European Hb CS.

Conclusions

Hb CS is commonly found in combination with other thalassemias among Southeast Asian populations. Accurate genotyping of the cases requires both hematologic and DNA analyses. At least two independent origins are associated with the Hb CS gene which could indirectly explain the high prevalence of this Hb variant in the region.     

Alpha-thalassemia in northern Thailand. Frequency of deletional types characterized at the DNA level

The frequency of alpha-thalassemias in northern Thailand was estimated using DNA techniques. Among 106 healthy adult Thais from the Chiangmai area, 28 were shown to carry alpha-globin gene anomalies. There were 19 heterozygotes and 1 homozygote for alpha-thalassemia-2. One of the alpha-thalassemia-2 deletions was of the -alpha 4.2 type and the remaining 20 of the -alpha 3.7 type (subtype I). Deletions of both alpha-globin genes on one chromosome (alpha-thalassemia-1) of the Southeast Asian type were observed in 5 cases, and 3 alpha-globin gene triplications were identified. Compared with a previous report on alpha-thalassemia in northern Thailand which was based on the determination of hemoglobin Bart's in cord blood, the present DNA study reveals a similar frequency of alpha-thalassemia-2 but a considerably lower frequency of alpha-thalassemia-1.     

Hemoglobinopathy: Molecular Epidemiological Characteristics and Health Effects on Hakka People in the Meizhou Region,Southern China

Background

Hemoglobinopathies are the most common inherited diseases in southern China. However, there have been only a few epidemiological studies of hemoglobinopathies in Guangdong province.

Materials and Methods

Peripheral blood samples were collected from 15299 “healthy” unrelated subjects of dominantly ethnic Hakka in the Meizhou region, on which hemoglobin electrophoresis and routine blood tests were performed. Suspected cases with hemoglobin variants and hereditary persistence of fetal hemoglobin (HPFH) were further characterized by PCR, DNA sequencing, reverse dot blot (RDB) or multiplex ligation-dependent probe amplification (MLPA). In addition, 1743 samples were randomly selected from the 15299 subjects for thalassemia screening, and suspected thalassemia carriers were identified by PCR and RDB.

Results

The gene frequency of hemoglobin variants was 0.477% (73/15299). The five main subgroups of the ten hemoglobin variants were Hb E, Hb G-Chinese, Hb Q-Tahiland, Hb New York and Hb J-Bangkok. 277 cases (15.89%, 277/1743) of suspected thalassemia carriers with microcytosis (MCV<82 fl) were found by thalassemia screening, and were tested by a RDB gene chip to reveal a total of 196 mutant chromosomes: including 124 α-thalassemia mutant chromosomes and 72 β-thalassemia mutant chromosomes. These results give a heterozygote frequency of 11.24% for common α and β thalassemia in the Hakka population in the Meizhou region. 3 cases of HPFH/δβ-thalassemia were found, including 2 cases of Vietnamese HPFH (FPFH-7) and a rare Belgian ^Gγ(^Aγδβ)⁰–thalassemia identified in Chinese.

Conclusions

Our results provide a detailed prevalence and molecular characterization of hemoglobinopathies in Hakka people of the Meizhou region. The estimated numbers of pregnancies each year in the Meizhou region, in which the fetus would be at risk for β thalassemia major or intermedia, Bart’s hydrops fetalis, and Hb H disease, are 25 (95% CI, 15 to 38), 40 (95% CI, 26 to 57), and 15 (95% CI, 8 to 23), respectively.     

Prevalence of βS-globin gene haplotypes, α-thalassemia (3.7 kb deletion) and redox status in patients with sickle cell anemia in the state of Paraná, Brazil

The aim of this study was to determine the frequency of beta S-globin gene (β^S globin) haplotypes and alpha thalassemia with 3.7 kb deletion (−α^3.7kb thalassemia) in the northwest region of Paraná state, and to investigate the oxidative and clinical-hematological profile of β^S globin carriers in this population. Of the 77 samples analyzed, 17 were Hb SS, 30 were Hb AS and 30 were Hb AA. The β^Sglobin haplotypes and −α^3.7kb thalassemia were identified using polymerase chain reaction.Trolox equivalent antioxidant capacity (TEAC) and lipid peroxidation (LPO) were assessed spectophotometrically. Serum melatonin levels were determined using high-performance liquid chromatography coupled to coulometric electrochemical detection. The haplotype frequencies in the SS individuals were as follows: Bantu- 21 (62%), Benin - 11 (32%) and Atypical- 2 (6%). Bantu/Benin was the most frequent genotype. Of the 47 SS and AS individuals assessed, 17% (n = 8) had the −α^3.7kb mutation. Clinical manifestations, as well as serum melatonin, TEAC and LPO levels did not differ between Bantu/Bantu and Bantu/Benin individuals (p > 0.05). Both genotypes were associated with high LPO and TEAC levels and decreased melatonin concentration. These data suggest that the level of oxidative stress in patients with Bantu/Bantu and Bantu/Benin genotypes may overload the antioxidant capacity.