Establishment of a genotyping method for the junior blood group and identification of a rare blood type with partial DVI.3 and Jr(a-) / 中华医学遗传学杂志

OBJECTIVE@#To develop a genotyping method for the Junior blood type and report on a rare blood type with Jr(a-).@*METHODS@#Healthy O-type RhD+ volunteer donors of the Shenzhen Blood Center from January to May 2021 (n = 1 568) and a pedigree with difficult cross-matching (n = 3) were selected as the study subjects. Serological methods were used for proband's blood type identification, unexpected antibody identification, and antibody titer determination. Polymerase chain reaction-sequence specific primer (PCR-SSP) method was used for typing the proband's RhD gene. ABCG2 gene coding region sequencing and a PCR-SSP genotyping method were established for determining the genotypes of the proband and his family members and screening of Jra antigen-negative rare blood type among the 1 568 blood donors.@*RESULTS@#The proband's ABO and RhD blood types were respectively determined as B and partial D (RHDDVI.3/RHD01N.01), Junior blood type Jra antigen was negative, and plasma had contained anti-D and anti-Jra. Sequencing of the ABCG2 gene revealed that the proband's genotype was ABGG201N.01/ABGG201N.01 [homozygous c.376C>T (p.Gln126X) variants], which is the most common Jr(a-) blood type allele in the Asian population. Screening of the voluntary blood donors has detected no Jr(a-) rare blood type. Statistical analysis of the heterozygotes suggested that the allelic frequency for ABCG2*01N.01 (c.376T) was 0.45%, and the frequency of Jr(a-) rare blood type with this molecular background was about 0.2‰.@*CONCLUSION@#A very rare case of partial DVI.3 type and Jr(a-) rare blood type has been identified. And a method for identifying the Junior blood type through sequencing the coding regions of the ABCG2 gene and PCR-SSP has been established.

Genetic analysis of a Chinese pedigree with an allele dropout at the HLA-B locus / 中华医学遗传学杂志

OBJECTIVE@#To delineate a deletional mutation of the HLA-B gene in a Chinese pedigree.@*METHODS@#A female patient with acute myeloid leukemia who had visited Liuzhou People's Hospital in April 2022 was selected as the study subject. Routine human leukocyte antigen (HLA) was determined by using PCR-sequence specific oligonucleotide polymorphism (PCR-SSOP) and PCR-sequence-based typing (PCR-SBT) methods. Next generation sequencing (NGS) was used to validate the candidate variant in the HLA-B gene.@*RESULTS@#The PCR-SBT and SSOP results for the HLA-B locus were inconsistent for the patient and her daughter. The SSOP results of the two individuals were HLA-B*35:01, 40:02 and HLA-B*35:01, 40:01, respectively. However, the PCR-SBT results has indicated a mismatch with the nearest HLA-B*35:01 at exon 4. NGS results showed that the HLA-B*35:01 had a 9 bp deletion in the intron 5. The patient's husband was HLA-B*40:01, 58:01, which was normal.@*CONCLUSION@#The variant in intron 5 of the HLA-B gene in this pedigree has mapped to a primer-binding region for the SBT reagent, which has affected the accuracy of PCR-SBT results.

Analysis of genetic polymorphisms and a novel tri-allelic cloning sequence for the D13S317 locus among an ethnic Han Chinese population / 中华医学遗传学杂志

OBJECTIVE@#To study the genetic polymorphisms of short-tandem repeats (STR) for the D13S317 locus among an ethnic Han Chinese population and verify a novel tri-allelic pattern identified for the locus.@*METHODS@#A total of 378 paternity test cases from Guangdong Forensic Authentication Institute from October 17, 2017 to December 28, 2017 were selected as the study subjects. A GlobalFilerTM Express kit was used for the STR genotyping. Samples suspected for having a novel tri-allelic pattern were verified with a PowerPlex 21 kit. Potential variant of the primer-binding region and flanking sequences underlying the tri-allelic pattern was excluded by molecular cloning and sequencing.@*RESULTS@#Six alleles were detected for the D13S317 locus, with the characteristic distribution frequencies being 8 (29.1%), 9 (13.1%), 10 (15.21%), 11 (24.21%), 12 (13.89%) and 13 (3.44%), respectively. In one of the families, the D13S317 locus of the proband was suspected to harbor a triband allele (8, 9, 10). A re-test has confirmed the result of initial test. Molecular cloning and sequencing analysis of the D13S317 locus in the proband and his daughter has failed to find allelic variants in the primer-binding region and flanking sequence, which has confirmed the novel tri-allelic pattern for the locus.@*CONCLUSION@#A novel type 2 tri-allelic pattern (8, 9, 10) at the D13S317 locus has been identified among the ethnic Han Chinese population. The pattern has not been transmitted to the female offspring, and has been included in the international STRBase database for the first time.

Fixation of pfcrt chloroquine resistance alleles in Plasmodium falciparum clinical isolates collected from unrest tribal agencies of Pakistan / Fixação de alelos de resistência à cloroquina pfcrt em isolados clínicos de Plasmodium falciparum coletados de agitações de agências tribais do Paquistão

Abstract Plasmodium falciparum resistance to Chloroquine (CQ) is a significant cause of mortality and morbidity worldwide. There is a paucity of documented data on the prevalence of CQ-resistant mutant haplotypes of Pfcrt and Pfmdr1 genes from malaria-endemic war effected Federally Administered Tribal Areas of Pakistan. The objective of this study was to investigate the prevalence of P. falciparum CQ-resistance in this area. Clinical isolates were collected between May 2017 and May 2018 from North Waziristan and South Waziristan agencies of Federally Administrated Trial Area. Subsequently, Giemsa-stained blood smears were examined to detect Plasmodium falciparum. Extraction of malarial DNA was done from microscopy positive P. falciparum samples, and P. falciparum infections were confirmed by nested PCR (targeting Plasmodium small subunit ribosomal ribonucleic acid (ssrRNA) genes). All PCR confirmed P. falciparum samples were sequenced by pyrosequencing to find out mutation in Pfcrt gene at codon K76T and in pfmdr1 at codons N86Y, Y184F, N1042D, and D1246Y. Out of 121 microscopies positive P. falciparum cases, 109 samples were positive for P. falciparum by nested PCR. Pfcrt K76T mutation was found in 96% of isolates, Pfmdr1 N86Y mutation was observed in 20%, and 11% harboured Y184F mutation. All samples were wild type for Pfmdr1 codon N1042D and D1246Y. In the FATA, Pakistan, the frequency of resistant allele 76T remained high despite the removal of CQ. However, current findings of the study suggest complete fixation of P. falciparum CQ-resistant genotype in the study area.

Resumo A resistência do Plasmodium falciparum à cloroquina (CQ) é uma causa significativa de mortalidade e morbidade em todo o mundo. Há uma escassez de dados documentados sobre a prevalência de haplótipos mutantes CQ-resistentes dos genes Pfcrt e Pfmdr1 da guerra endêmica da malária em áreas tribais administradas pelo governo federal do Paquistão. O objetivo deste estudo foi investigar a prevalência de resistência a CQ de P. falciparum nesta área. Isolados clínicos foram coletados entre maio de 2017 e maio de 2018 nas agências do Waziristão do Norte e do Waziristão do Sul da Área de Ensaio Administrada Federalmente. Posteriormente, esfregaços de sangue corados com Giemsa foram examinados para detectar Plasmodium falciparum. A extração do DNA da malária foi feita a partir de amostras de P. falciparum positivas para microscopia, e as infecções por P. falciparum foram confirmadas por nested PCR (visando genes de ácido ribonucleico ribossômico de subunidade pequena de Plasmodium (ssrRNA)). Todas as amostras de P. falciparum confirmadas por PCR foram sequenciadas por pirosequenciamento para descobrir a mutação no gene Pfcrt no códon K76T e em pfmdr1 nos códons N86Y, Y184F, N1042D e D1246Y. De 121 microscopias de casos positivos de P. falciparum, 109 amostras foram positivas para P. falciparum por nested PCR. A mutação Pfcrt K76T foi encontrada em 96% dos isolados, a mutação Pfmdr1 N86Y foi observada em 20% e 11% abrigou a mutação Y184F. Todas as amostras eram do tipo selvagem para o códon N1042D e D1246Y de Pfmdr1. No FATA, Paquistão, a frequência do alelo resistente 76T permaneceu alta apesar da remoção de CQ. No entanto, as descobertas atuais do estudo sugerem a fixação completa do genótipo resistente a CQ de P. falciparum na área de estudo.

Analysis of genotypes on 850 newborns with SLC26A4 single-allele mutation and the phenotypes of those with second variant / 中华耳鼻咽喉头颈外科杂志

Objective: To clarify the phenotypes of the newborns with SLC26A4 single-allele mutation in deafness genetic screening and second variant; to analyze the SLC26A4 genotype and hearing phenotype. Methods: 850 newborns born in Beijing from April 2015 to December 2019 were included and there were 468 males and 382 females. They received genetic deafness screening for 9 or 15 variants, with the result of SLC26A4 single-allele mutation. Firstly, three step deafness gene sequencing was adopted in this work, i.e., the first step was "SLC26A4 gene whole exons and splice sites" sequencing; the second step was "SLC26A4 gene promoter, FOXI1 gene and KCNJ10 gene whole exons" sequencing; and the third step was detection for "SLC26A4 gene copy number variation". Secondly, we collected the results of newborn hearing screening for all patients with the second mutation found in the three step test, and conducted audiological examinations, such as acoustic immittance, auditory brainstem response and auditory steady state response. Thirdly, for novel/VUS mutations, we searched the international deafness gene database or software, such as DVD, ClinVar and Mutation Taster, to predict the pathogenicity of mutations according to the ACMG guideline. Lastly, we analyzed the relationship between genotype and phenotype of newborns with SLC26A4 single allele mutation. Results: Among 850 cases, the median age of diagnosis was 4 months. In the first step, 850 cases were sequenced. A total of 32 cases (3.76%, 32/850) of a second variants were detected, including 18 cases (2.12%, 18/850) with identified pathogenic variants; 832 cases were sequenced and 8 cases of KCNJ10 gene missense variants were detected among the second step. No missense mutations in the FOXI1 gene and abnormal SLC26A4 gene promoter were detected; the third step sequencing results were all negative. Genotypes and hearing phenotypes included 18 cases combined with the second clear pathogenic variant, 16 cases (16/18) referred newborn hearing screening and 2 cases (2/18) passed in both ears; degree of hearing loss consisted of 18 profound ears (18/36), 13 severe ears (13/36) and 5 moderate ears (5/36); audiogram patterns comprised 17 high frequency drop ears (17/36), 14 flat ears (14/36), 3 undistinguished ears (3/36), and 2 U shaped ears (2/36); 11 cases underwent imaging examination, all of which were bilateral enlarged vestibular aqueduct. As for 22 cases of other genotypes, all passed neonatal hearing screening and the hearing diagnosis was normal, including 9 cases with VUS or possibly novel benign variants, 8 cases with KCNJ10 double gene heterozygous variants, and 5 cases with double heterozygous variants. Conclusions: The probability of individuals with SLC26A4 single-allele variant who merge with a second pathogenic variant is 2.12%, all of which are SNV, which can provide scientific basis for the genetic diagnosis and genetic counseling of SLC26A4 variants. Those who have merged with second pathogenic variant are all diagnosed with sensorineural hearing loss. Patients with KCNJ10 gene mutations do not manifest hearing loss during the infancy, suggesting the need for further follow-up.

Using Next-Generation Sequencing Technology to Confirm the HLA Rare Alleles Detected by PCR-SSOP / 中国实验血液学杂志

OBJECTIVE@#To confirm the HLA genotypes of the samples including 4 cases of magnetic bead probe HLA genotyping result pattern abnormality and 3 cases of ambiguous result detected by PCR sequence-specific oligonudeotide probe (SSOP) method.@*METHODS@#All samples derived from HLA high-resolution typing laboratory were detected by PCR-SSOP. A total of 4 samples of magnetic bead probe HLA genotyping result pattern abnormality and 3 samples of ambiguous result were further confirmed by PCR sequence-based typing (SBT) technology and next-generation sequencing (NGS) technology.@*RESULTS@#A total of 4 samples of magnetic bead probe HLA genotyping result pattern abnormality were detected by PCR-SSOP method. The results of SBT and NGS showed that the HLA-A genotype of sample 1 did not match any known genotypes. NGS analysis revealed that the novel allele was different from the closest matching allele A*31:01:02:01at position 154 with G>A in exon 2, which resulting in one amino acid substitution at codon 28 from Valine to Methionine (p.Val28Met). The HLA-C genotype of sample 2 was C*03:119, 06:02, sample 3 was C*03:03, 07:137, and sample 4 was B*55:02, 55:12. A total of 3 samples with ambiguous result were initially detected by PCR-SSOP method. The re-examination results of SBT and NGS showed that the HLA-B genotype of sample 5 was B*15:58, 38:02, sample 6 was DRB1*04:05, 14:101, and sample 7 was DQB1*03:34, 05:02. Among them, alleles C*03:119, C*07:137 and DRB1*14:101 were not included in the Common and Well-documented Alleles (CWD) v2.4 of the Chinese Hematopoietic Stem Cell Donor Database.@*CONCLUSION@#The abnormal pattern of HLA genotyping results of magnetic probe by PCR-SSOP method suggests that it may be a rare allele or a novel allele, which needs to be verified by sequencing.

Analysis of Gene Recombination between HLA-B and -DRB1, HLA-DQB1 and -DPB1 Loci / 中国实验血液学杂志

OBJECTIVE@#To investigate the recombinations within the human leukocyte antigen (HLA) region in two families.@*METHODS@#Genomic DNA was extracted from the peripheral blood specimens of the different family members. HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1 loci were genotyped using polymerase chain reaction-sequence specific oligonucleotide probing technique (PCR-SSO) and next-generation sequencing technique. HLA haplotype was determined by genetic analysis of the pedigree.@*RESULTS@#The haplotypes of HLA-A*11:01~C*03:04~B*13:01~DRB1*12:02~DQB1*03:01~DPB1*05:01:01G and HLA-A*03:01~C*04:01~B*35:03~DRB1*12:01~DQB1*03:01~DPB1*04:01:01G in the family 1 were recombined between HLA-B and HLA-DRB1 loci, which formed the haplotype of HLA-A*11:01~C*03:04~B*13:01~DRB1* 12:01~DQB1*03:01~DPB1*04:01:01G. The haplotypes of HLA-A *02:06~C*03:03~B*35:01~DRB1*08:02~DQB1*04:02~ DPB1*13:01:01G and HLA-A *11:01~C*07:02~B*38:02~DRB1*15:02~DQB1*05:01~DPB1*05:01:01G in the family 2 were recombined between HLA-DQB1 and HLA-DPB1 loci, which formed the haplotype of HLA-A*02:06~C*03:03~B*35:01~ DRB1*08:02~DQB1*04:02~DPB1*05:01:01G.@*CONCLUSION@#The gene recombination events between HLA-B and -DRB1, HLA-DQB1 and -DPB1 loci were found respectively in two Chinese Han families.

RHD Gene Analysis of A Blood Donor with Del Phenotype / 中国实验血液学杂志

OBJECTIVE@#To analyze the RHD genotype of a blood donor with Del phenotype in Yunnan.@*METHODS@#Rh serological phenotype was identified. RHD gene was detected by PCR-SSP typing, and its 10 exons were sequenced. Exon 9 was amplified for sequencing and analysis. RHD zygosity was detected.@*RESULTS@#The Rh phenotype of this specimen was CcDelee. Genomic DNA exhibited a 1 003 bp deletion spanning from intron 8, across exon 9 into intron 9. The deletion breakpoints occurred between two 7-bp short tandem repeat sequences. There was no variation in the sequences of the remaining exons. The Rh hybridization box test showed that there was one RHD negative allele.@*CONCLUSION@#This specimen is Del type caused by deletion of RHD exon 9.

Serological Characteristics of Subtype A Caused by New A Allele Mutation and a Family Survey / 中国实验血液学杂志

OBJECTIVE@#In this study, the results of forward and reverse blood typing of a male patient diagnosed as bronchiectasis were inconsistent, which were type O and type A respectively. Multiple experiments including genotyping and sequencing and family investigation were carried out to determine the subtype of ABO blood group and explore the serological characteristics of this subtype.@*METHODS@#Standard serological techniques were used to conduct forward and reverse typing, reverse blood typing enhancement test, H antigen identification, absorption-elution test, salivary blood group substances test, and PCR-SSP method for ABO genotyping and exon 6 and 7 sequencing.@*RESULTS@#The proband's blood group was type O by forward typing, but antigen A could be detected by absorption-elution test, anti-A1 could be detected by reverse blood typing enhancement test, it was found that there was substance H but no substance A in saliva, and the serological characteristics were consistent with Ael subtype. Gene sequencing analysis showed that there was a c.625T>G base substitution on the basis of A102, which had never been reported before. Family survey showed that c.625T>G base substitution appeared in three generations of the family.@*CONCLUSION@#In this study, a new subtype A with Ael serological characteristics caused by c.625T>G mutation was identified. c.625T>G base substitution results in the weakening of A antigen, and this mutation can be stably passed down to future generations.

Research Progresses of Tri-Allelic Patterns in Autosomal STR in Forensic DNA Analysis / 法医学杂志

Tri-allelic pattern in autosomal STR is a common abnormal typing phenomenon in forensic DNA analysis, which brings difficulties and uncertainties to the evaluation of the evidence weight in actual cases. This paper reviews the types, formation mechanism, occurrence frequency, genetic pattern and quantitative evaluation of evidence of the tri-allelic pattern in autosomal STR in forensic DNA analysis. This paper mainly explains the formation mechanism and genetic patterns based on different types of tri-allelic pattern. This paper also discusses the determination of tri-allelic pattern and the quantitative method of evidence evaluation in paternity testing and individual identification. This paper aims to provide references for scientific and standardized analysis of this abnormal typing phenomenon in forensic DNA analysis.

Serological characteristics of ABO blood group and molecular genetic analysis of a Chinese pedigree with cisAB09 subtype / 中华医学遗传学杂志

OBJECTIVE@#To explore the serological characteristics of ABO blood group and molecular genetic mechanism for a Chinese pedigree with cisAB09 subtype.@*METHODS@#A pedigree undergoing ABO blood group examination at the Department of Transfusion, Zhongshan Hospital Affiliated to Xiamen University on February 2, 2022 was selected as the study subjects. Serological assay was carried out to determine the ABO blood group of the proband and his family members. Activities of A and B glycosyltransferases in the plasma of the proband and his mother were measured with an enzymatic assay. Expression of A and B antigens on the red blood cells of the proband was analyzed by flow cytometry. Peripheral blood samples of the proband and his family members were collected. Following extraction of genomic DNA, exons 1 to 7 of the ABO gene and their flanking introns were sequenced, and Sanger sequencing of exon 7 was carried out for the proband, his elder daughter and mother.@*RESULTS@#The results of serological assay suggested that the proband and his elder daughter and mother had an A2B phenotype, whilst his wife and younger daughter had an O phenotype. Measurement of plasma A and B glycosyltransferase activity suggested that the titers of B-glycosyltransferase activity were 32 and 256 for the proband and his mother, which were respectively below and above that of A1B phenotype-positive controls (128). Flow cytometry analysis showed that the expression of A antigen on the red blood cell surface of the proband has decreased, whilst the expression of B antigen was normal. Genetic sequencing confirmed that, in addition to an ABO*B.01 allele, the proband, his elder daughter and mother have harbored a c.796A>G variant in exon 7, which has resulted in substitution of the methionine at 266th position of the B-glycosyltransferase by valine and conformed to the characteristics of ABO*cisAB.09 allele. The genotypes of the proband and his elder daughter were determined as ABO*cisAB.09/ABO*O.01.01, his mother was ABO*cisAB.09/ABO*B.01, and his wife and younger daughter were ABO*O.01.01/ABO*O.01.01.@*CONCLUSION@#The c.796A>G variant of the ABO*B.01 allele has resulted in an amino acid substitution p.Met266Val, which probably underlay the cisAB09 subtype. The ABO*cisA B.09 allele encodes a special glycosyltransferase which can synthesize normal level of B antigen and low level of A antigen on the red blood cells.

Study of the molecular characteristics of a Bweak phenotype due to a novel c.398T>C variant of the ABO gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the molecular mechanism for an individual with Bweak subtype.@*METHODS@#Serological methods were used to identify the proband's phenotype. In vitro enzyme activity test was used to determine the activity of B-glycosyltransferase (GTB) in her serum. The genotype was determined by PCR amplification and direct sequencing of exons 5 to 7 and flanking sequences of the ABO gene. T-A cloning technology was used to isolate the haploids. The primary physical and chemical properties and secondary structure of the protein were analyzed with the ProtParam and PSIPRED software. Three software, including PolyPhen-2, SIFT, and PROVEAN, was used to analyze the effect of missense variant on the protein.@*RESULTS@#Serological results showed that the proband's phenotype was Bweak subtype with anti-B antibodies presented in her serum. In vitro enzyme activity assay showed that the GTB activity of the subject was significantly reduced. Analysis of the haploid sequence revealed a c.398T>C missense variant on the B allele, which resulted in a novel B allele. The 398T>C variant has caused a p.Phe133S substitution at position 133 of the GTB protein. Based on bioinformatic analysis, the amino acid substitution had no obvious effect on the primary and secondary structure of the protein, but the thermodynamic energy of the variant protein has increased to 6.07 kcal/mol, which can severely reduce the protein stability. Meanwhile, bioinformatic analysis also predicted that the missense variant was harmful to the protein function.@*CONCLUSION@#The weak expression of the Bweak subtype may be attributed to the novel allele of ABO*B.01-398C. Bioinformatic analysis is helpful for predicting the changes in protein structure and function.

Efficacy and safety of peginterferon-α2b for treatment of myeloproliterative neoplasms / 南方医科大学学报

OBJECTIVE@#To evaluate the clinical efficacy and adverse reactions of peginterferon-α2b for treatment of chronic myeloproliferative neoplasms (MPN).@*METHODS@#We retrospectively analyzed the data of 107 patients with MPN, including 95 with essential thrombocythemia (ET) and 12 with polycythemia vera (PV), who all received peginterferon-α2b treatment for at least 12 months. The clnical and follow-up data of the patients were analyzed to evaluate the efficacy and adverse reactions of the treatment.@*RESULTS@#After receiving peginterferon- α2b treatment, both ET and PV patients achieved high hematological remission rates, and the total remission rates did not differ significantly between the two groups (86% vs 78%, P>0.05). In the overall patients, the spleen index decreased by 13.5% (95%CI: 8.5%-18.5%) after the treatment. The patients with hematological remission showed a significantly greater reduction of the total symptom score than those without hematological remission (P < 0.01). The median percentage of JAK2V617F allele load of PV patients decreased from 67.23% (49.6%-84.86%) at baseline to 19.7% (0.57%-74.6%) after the treatment, and that of JAK2V617F-positive ET patients decreased from 48.97% (0.45%-74.24%) at baseline to 22.1% (0.33%-65.42%) after the treatment. Mild adverse reactions (grade 1-2) were observed in both ET and PV groups without significant differences between them. The overall incidence of thrombotic events during the treatment was 2.8% in these patients, and no serious adverse reactions were observed.@*CONCLUSION@#For patients with chronic myelodysplasia, peginterferon-α2b treatment can achieve a high peripheral blood cell remission rate and maintain a long-term stable state with good effect in relieving symptoms such as splenomegaly. Peginterferon- α2b treatment caused only mild adverse reactions, which can be tolerated by most of the patients.

Molecular Mechanism of a Rhesus D Variant Individual with RHD*845A/1227A / 中国实验血液学杂志

OBJECTIVE@#To explore the genetic mutation mechanism of a rare Rhesus D variant individual.@*METHODS@#Regular serological assay was used for determination of Rh type for the sample. Indirect anti-human globulin test (IAT) was used to confirm the RhD antigen and screen the antibodies. D-screen reagent was used to analyze the RhD epitopes of the sample. RHD genotype and RHD zygosity testing of the sample were detected by palymerase chain reaction with sequence-specific primers (PCR-SSP). The full length coding region of RHD gene was sequenced. RHD mRNA was detected using reverse transcription polymerase chain reaction (RT-PCR). The PCR products were cloned and sequenced.@*RESULTS@#The RhD blood group of the sample was determined as weak D, and the Rh phenotype was CcDEe. The antibody screening was negative. The sample tested with all monoclonal anti-Ds in D-screen showed the D epitope profiles as partial D types. The analysis of RHD gene sequence indicated that the individual with RHD c.845G/A and RHD c.1227G/A base heterozygosis. Three kinds of alternative splicing isoforms were obtained by TA cloning and sequencing.@*CONCLUSION@#The object has RHD c.845G/A and RHD c.1227G/A mutation. This heterozygous mutation is responsible for the low expression of RhD antigen on the red blood cells of the sample.

Association between HLA-DRB1 gene polymorphisms and genetic susceptibility of early-onset severe preeclampsia / 中国当代儿科杂志

OBJECTIVES@#To explore the correlation between the single nucleotide polymorphisms (SNP) of rs3135388, rs114293611 and rs142804168 of HLA-DRB1 gene and early-onset severe preeclampsia (sPE).@*METHODS@#Blood samples were collected from 102 early-onset sPE mothers and their neonates (sPE group), as well as 120 normotensive mothers and their neonates (control group). Sanger sequencing was performed to compare the genotype distribution, allele frequencies, and differences in genotype distribution after maternal-infant compatibility between the two groups.@*RESULTS@#Statistically significant differences in genotype distribution at rs114293611 of HLA-DRB1 gene were observed between sPE and control groups in both mothers and neonates (P<0.05). The frequency of the T allele at rs114293611 was higher in the sPE group of neonates than that in the control group (P<0.05), while no significant difference was found between the two groups of mothers (P>0.05). The maternal-infant genotype compatibility analysis showed significant differences in genotype distribution between sPE and control groups (P<0.05). There were no significant differences in genotype distribution and allele frequencies at rs3135388 and rs142804168 of HLA-DRB1 gene between the two groups of mothers and neonates (P>0.05).@*CONCLUSIONS@#The SNP at rs114293611 of HLA-DRB1 gene may be associated with the development of early-onset sPE in mothers. Maternal-infant genotype compatibility abnormality at rs114293611 of HLA-DRB1 gene may be a predisposition factor for the development of sPE.

Association of SLC6A4 gene c.*670T>G polymorphism with the risk for asthma and peripheral blood cytological characteristics among ethnic Zhuang Chinese population / 中华医学遗传学杂志

OBJECTIVE@#To assess the association of SLC6A4 gene c.*670T>G polymorphism with the risk for asthma and peripheral blood cytological characteristics among ethnic Zhuang Chinese from Guangxi, China.@*METHODS@#From May 2017 to March 2020, 258 patients diagnosed with asthma and 244 healthy controls were recruited from the Affiliated Hospital of Youjiang Minzhu Medical College and the People's Hospital of Hechi. Genotypes of the c.*670T>G polymorphism were determined by Sanger sequencing. Flow cytometry was used in combination with an electrical impedance method for the counting and classification of peripheral blood cells.@*RESULTS@#Compared with the T allele, the G allele of the c.*670T>G polymorphism was associated with the risk for asthma in the population (OR = 1.54, 95%CI = 1.15-2.06; P = 0.004). Compared with the GT and TT genotypes, homozygous GG genotype also comprised a risk factor (OR = 1.66, 95%CI = 1.16-2.38; P = 0.005). Stratification of the risk factors showed that the homozygous GG genotype has increased the risk of asthma in males and urban residents (P < 0.01). The erythrocyte, hemoglobin and platelet counts of the asthma group were significantly higher than the control group (P < 0.001). The GG, GT and TT genotypes have respectively accounted for 82.35%, 17.65% and 0% of the samples with platelets exceeding the normal value. The overall platelet level of GG genotype was higher than GT+TT genotype (P < 0.05). The significant association was verified by the false positive report probability, and at a prior probability level of 0.1, G vs. T false positive probability was 0.071, and GG vs. GT+TT false positive probability was 0.153.@*CONCLUSION@#The GG genotype of the c.*670T>G polymorphism is associated with the risk for asthma among ethnic Zhuang Chinese from northwest Guangxi. Above finding has also enriched the genotypic data and peripheral blood phenotype for this polymorphism.

Do boys with MAOA_LPR*2R allele present cognitive and learning impairments? / Meninos com o alelo maoa_lpr*2r apresentam prejuízos cognitivos e de aprendizagem?

ABSTRACT. Monoamine oxidase A (MAOA) polymorphisms have been associated with antisocial disorders. Less attention has been paid to the cognitive functioning of individuals with different MAOA alleles. No study has described the cognitive phenotype associated with the less frequent, low enzyme activity allele, MAOA_LPR*2R. Objective: We describe the cognitive correlates of boys having MAOA_LPR*2R allele, ascertained in a sample of school children with normal intelligence, not referred for behavioral disorders. Methods: Participants were eight boys, attending from the second to fifth grades in state-run schools. They were identified among 712 children with typical general cognitive ability, genotyped for MAOA_LPR polymorphism. Participants were assessed with general intelligence, mathematics and spelling achievement, and verbal and visuospatial working memory tests. Neuropsychological performance was compared to published standards, using 1 SD below the mean as a cutoff value for low performance. Results: Intelligence of boys with MAOA_LPR*2R allele varied from above average (N=2) to low average in the other children. Five out of eight boys with the MAOA_LPR*2R allele had low mathematics achievement, and three presented additional difficulties with spelling. Four out of eight children had low short-term and working memory performance. Discussion: This is the first study describing cognitive correlates and school performance in boys having the MAOA_LPR*2R allele. Having this allele, and therefore, probably low MAO-A activity, does not necessarily imply low intelligence or low school performance. However, learning difficulties, particularly in math, and low working memory performance were observed in boys having this allele. This suggests a role of MAOA in learning difficulties.

RESUMO. Polimorfismos da monoaminoxidase A (MAOA) são associados a transtornos antissociais. Menos atenção tem sido dada ao funcionamento cognitivo de indivíduos com diferentes alelos de MAOA. Nenhum estudo descreveu o fenótipo cognitivo associado ao alelo menos frequente, de baixa atividade enzimática, MAOA_LPR*2R. Objetivo: Descrevemos os correlatos cognitivos de meninos com o alelo MAOA_LPR*2R, identificados em uma amostra de escolares com inteligência normal, não encaminhados por transtornos de comportamento. Métodos: Oito meninos com o alelo MAOA_LPR*2R foram identificados entre 712 crianças genotipadas, com inteligência típica, que cursavam do 2º ao 5º ano em escolas públicas. Foram avaliados: inteligência, desempenho em matemática e ortografia, memória de trabalho verbal e visuoespacial. O desempenho foi comparado a normas publicadas, utilizando-se 1 desvio padrão (DP) abaixo da média como ponto de corte para desempenho rebaixado. Resultados: A inteligência dos meninos com alelo MAOA_LPR*2R variou de acima da média (N=2) a médio-inferior nas demais crianças. Cinco dos oito meninos com alelo MAOA_LPR*2R apresentaram desempenho rebaixado em matemática e três apresentaram dificuldades adicionais em ortografia. Quatro dos oito meninos apresentaram baixo desempenho de memória de curto prazo e de trabalho. Discussão: Este é o primeiro estudo a descrever os correlatos cognitivos e o desempenho escolar em meninos com alelo MAOA_LPR*2R. Ter esse alelo não significa necessariamente baixa inteligência ou baixo desempenho escolar. No entanto, dificuldades de aprendizagem, principalmente em matemática, e desempenho rebaixado da memória de trabalho foram observados em mais da metade dos meninos com esse alelo. Isso sugere um papel do MAOA nas dificuldades de aprendizagem.

FMR1 alleles in women with idiopathic infertility / Alelos do gene FMR1 em mulheres com infertilidade idiopática

INTRODUCTION: The frequency of the premutation alleles of the FMR1 gene varies from 1:100 to 1:260 Israeli, Canadian, Finnish and American women, but it is unknown in Brazil. Premutation carriers may have reduced reproductive age and are at risk of transmitting the expanded allele to their offspring, and consequently fragile X syndrome. OBJECTIVE: To observe the distribution range of the FMR1 gene alleles in a population of women with idiopathic infertility, without symptoms of premature ovarian insufficiency. METHODS: The presence of premutation in FMR1 was assessed by conventional PCR, agarose, and acrylamide gel and analysis of fragments in capillary electrophoresis. Lymphocyte DNA obtained from 283 women undergoing infertility treatment was analyzed. RESULTS: 169 patients had the normal heterozygous allele (59.7%), 114 had the normal homozygous allele (40.6%) and no patient had the premutation. Premature ovarian insufficiency is seen in 20 to 30% of women with the permutated allele. Thus, the condition can be asymptomatic in a large part of the premutation carriers. Brazil has a diverse population and, therefore, the allele frequencies of many gene variants are unknown. Previous Brazilian studies have shown a low frequency of the premutation allele in different patient cohorts. Corroborating these articles, the results demonstrated that the frequency of the premutation allele is low in the infertile women population studied. CONCLUSION: Tracking the size of the FMR1 gene alleles allows the expansion of knowledge about the frequency of risk alleles associated with genetic diseases in the Brazilian population.

INTRODUÇÃO: A frequência dos alelos pré-mutados do gene FMR1 varia de 1:100 e 1:260 mulheres israelenses, canadenses, finlandesas e americanas, mas é desconhecida no Brasil. Portadoras da pré-mutação podem apresentar redução da idade reprodutiva e possuem risco de transmissão do alelo expandido para a prole, e consequentemente a Síndrome do X frágil. OBJETIVO: Observar a faixa de distribuição dos alelos do gene FMR1 em uma população de mulheres com infertilidade idiopática, sem sintomas de insuficiência ovariana prematura. MÉTODOS: A presença da pré-mutação em FMR1 foi avaliada por PCR convencional, gel de agarose e acrilamida e análise de fragmentos em eletroforese capilar. Analisou-se DNA de linfócitos obtidos de 283 mulheres em tratamento de infertilidade. RESULTADOS: Foi observado que 169 pacientes apresentam o alelo heterozigoto normal (59,7%), 114 apresentam o alelo homozigoto normal (40,6%) e nenhuma paciente apresentou a pré-mutação. A insuficiência ovariana prematura é observada em 20 a 30% das mulheres portadoras do alelo pré-mutado. Assim, a presença de um alelo pré-mutado pode ser assintomática em grande parte dos casos. O Brasil possui uma população diversificada e, portanto, as frequências alélicas de muitas variantes gênicas são desconhecidas. Estudos brasileiros anteriores mostraram uma baixa frequência do alelo pré-mutado em diferentes coortes de pacientes. Corroborando estes autores, os resultados demonstram que frequência do alelo pré-mutado é baixa na população de mulheres inférteis estudada. CONCLUSÃO: O rastreamento do tamanho dos alelos do gene FMR1 permite ampliar o conhecimento sobre a frequência dos alelos de risco para doenças genética na população brasileira.

No association between dopamine D2 receptor (DRD2) alleles and crack/cocaine dependence in Brazilians

INTRODUCTION: The causal mechanisms behind crack/cocaine use are still unknown, but genetic influences are suggested. OBJECTIVE: To investigate the relationship between the genetic polymorphism TaqI (rs1800497) in the dopamine D2 receptor (DRD2) gene and susceptibility to crack/cocaine dependence in a group of addicts to crack/cocaine and a non-addicted group. METHODS: The case group (n=515) was composed of crack/cocaine-dependent men and the control group (n=106) comprised men who were considered not dependent on crack/cocaine. The oral hygiene habits, decayed, missing, and filled teeth index, gingival index, and plaque index were evaluated. The reference single nucleotide polymorphism (rs1800497 C/T) of the DRD2 gene was genotyped by a real-time polymerase chain reaction technique. Student's t-tests for independent samples or the non-parametric Mann-Whitney test were used to compare groups regarding quantitative variables. RESULTS: The case group showed a mean time of 9.91±7.03 years of crack use, and 61.06±92.96 stones/week. The socio-demographic profile of the sample was White, single men, with basic education, blue-collar worker, smoker, and reporting alcohol use. There was a high frequency of gingival inflammation, plaque accumulation, and caries experience. For all genetic models tested, there was no significant difference in the genotypic frequency in rs1800497 of the DRD2 gene, between case and control groups (p>0.05). CONCLUSION: The genetic variant in the DRD2 did not increase the vulnerability to develop crack/cocaine dependence. The complex genetic nature of crack/cocaine dependence and a large variation of DRD2 allele frequencies, depending on the population group sampled, could be one explanation for the no association.

The A allele of the rs759853 single nucleotide polymorphism in the AKR1B1 gene confers risk for diabetic kidney disease in patients with type 2 diabetes from a Brazilian population

ABSTRACT Objective: The AKR1B1 gene encodes an enzyme that catalyzes the reduction of glucose into sorbitol. Chronic hyperglycemia in patients with diabetes mellitus (DM) leads to increased AKR1B1 affinity for glucose and, consequently, sorbitol accumulation. Elevated sorbitol increases oxidative stress, which is one of the main pathways related to chronic complications of diabetes, including diabetic kidney disease (DKD). Accordingly, some studies have suggested the rs759853 polymorphism in the AKR1B1 gene is associated with DKD; however, findings are still contradictory. The aim was to investigate the association of the rs759853 polymorphism in the AKR1B1 gene and DKD. Materials and methods: The sample comprised 695 patients with type 2 DM (T2DM) and DKD (cases) and 310 patients with T2DM of more than 10 years' duration, but no DKD (controls). The polymorphism was genotyped by real-time PCR. Results: Allelic and genotype frequencies of this polymorphism did not differ significantly between groups. However, the A/A genotype was associated with risk for DKD after adjustment for gender, triglycerides, BMI, presence of hypertension and diabetic retinopathy, and duration of DM, under both recessive (P = 0.048) and additive (P = 0.037) inheritance models. Conclusion: Our data suggest an association between the AKR1B1 rs759853A/A genotype and risk for DKD in Brazilians T2DM patients.