Genetic analysis of a Chinese family affected with α-dystroglycanopathy due to variant of B3GALNT2 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese pedigree affected with recurrent fetal hydrocephalus.@*METHODS@#A couple who had presented at the Affiliated Hospital of Putian College on March 3, 2021 was selected as the study subject. Following elective abortion, fetal tissue and peripheral blood samples were respectively obtained from the abortus and the couple, and were subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing.@*RESULTS@#The fetus was found to harbor compound heterozygous variants of the B3GALNT2 gene, namely c.261-2A>G and c.536T>C (p.Leu179Pro), which were inherited from its father and mother, respectively.According to the guidelines of American College of Medical Genetics and Genomics, both variants were classified as pathogenic (PVS1+PM2_Supporting; PM3+PM2_Supporting+PP3+PP4).@*CONCLUSION@#The compound heterozygous variants of the B3GALNT2 gene probably underlay the α-dystroglycanopathy in this fetus. Above results have provided a basis for genetic counseling of this pedigree.

Study of a Chinese pedigree carrying a novel variant of α-1, 3-N-acetyl galactosaminyl transferase gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese pedigree with a novel ABO subtype.@*METHODS@#The proband and his family members were subjected to serological analysis, and their genotypes were determined by fluorescence PCR and direct sequencing of the coding regions of the ABO gene. Exons 6 to 7 of the ABO gene were also subjected to clone sequencing for haplotype analysis.@*RESULTS@#The proband was determined as an AxB subtype. By fluorescence PCR, he was typed as A/B. Clone sequencing has revealed a insertional mutation c.797_798 insT in exon 7 of the ABO gene, which yielded a novel allele. Pedigree analysis confirmed that the novel ABO*A1.02 allele carried by the proband and his sister was inherited from their father. The c.797_798insT mutation has been submitted to GenBank with an accession number of MK125137.@*CONCLUSION@#The c.797_798insT mutation of exon 7 of the ABO gene probably has led to weakened expression of A antigen.

Expression of CHPF modulates cell proliferation and invasion in lung cancer

Lung cancer is the most common malignancy worldwide and is characterized by rapid progression, aggressive behavior, frequent recurrence, and poor prognosis. The TCGA database indicates that chondroitin polymerizing factor (CHPF) is overexpressed in human lung cancer tissues compared with normal tissues and this overexpression corresponds to shorter overall survival in lung cancer patients. In this study, to investigate the function of CHPF in lung cancer, lentiviral vectors expressing CHPF shRNA were stably transduced into A549 and H1299 cells. Compared to shCtrl cells, CHPF knockdown cells had significantly reduced proliferation. Furthermore, the silencing of CHPF in A549 and H1299 cells resulted in apoptotic induction, which led to decreased colony formation. Wound healing and transwell invasion assays revealed that CHPF could positively regulate the migration of lung cancer cells. The tumorigenic role of CHPF was also validated in nude mouse xenograft models. Affymetrix gene chip analysis indicated that CHPF regulated the proliferation and invasion of lung cancer cells through CDH1, RRM2, MKI67, and TNFRSF10B. We thus highlight CHPF as a novel target for lung cancer treatment.

Study of 467C>T and 745C>T variants of alpha-1, 3-N-acetylgalactoseaminotransferase gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the effect of alpha-1,3-N-acetylgalactosaminyltransferase gene variants on A antigen expression in a family where a member was suspected for a rare A3 subtype of the ABO variant.</p><p><b>METHODS</b>Serological assay was carried out to determine the ABO blood group of the proband and his family members. To determine the haploid of the alpha-1,3-N-acetylgalactosaminyltransferase gene of the proband, DNA was extracted and genotyped with sequence-specific primer PCR (PCR-SSP) followed by direct sequencing and cloning of exons 6 and 7 of the ABO locus.</p><p><b>RESULTS</b>Weak A antigen was detected on red blood cells of the proband, while anti-A and anti-B antibodies were detected in his serum. DNA sequencing showed a 261delG mutation in exon 6, and two heterozygote mutations (467C>T and 745C>T) in exon 7 of the alpha-1,3-N-acetylgalactosaminyltransferase gene. Haplotype analysis has identified two alleles A307 and O01. Compared with the A101 allele, the A307 allele has harbored two nucleotides changes (467C>T and 745C>T), which resulted in substitution of two amino acids (P156L and R249W).</p><p><b>CONCLUSION</b>The 467C>T and 745C>T mutations of the alpha-1,3-N-acetylgalactosaminyltransferase gene can result in an A307 phenotype with reduced expression of A antigen.</p>

Genetic analysis of a case with A subtype of the ABO blood type / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze the serological features and related blood group genes of a donor with A subtype of the ABO blood type.</p><p><b>METHODS</b>The ABO blood group of the sample was determined, in addition with the activity of blood group glycosyltransferase and blood group secretory substances. Sanger sequencing was adopted to analyze the genotype of the blood group.</p><p><b>RESULTS</b>The proband was identified as A subtype (non-secretory type), with no detectable activities of a 1, 3-N-acetylgalactosyltransferase. DNA sequencing has identified a number of mutations including nt.261del/G and 297A/A of exon 6, and nt.467C/T, 806T/C and 1009A/G of exon 7. Clone sequencing has confirmed that the nt.806T>C exists at one allele and was a novel mutation. The proband genotype was A205/Onew (806T>C). The nt.806T>C of the exon 7 was confirmed to be a novel mutation, which was given a GenBank accession number KP341759. Family study showed that the genotype of the proband's father was Onew (806T>C)/O02, and that of his mother was A101/A205. The novel mutation of the proband has derived from his father.</p><p><b>CONCLUSION</b>The reduced A antigenicity of the sample was due to the A205 subtype allele and the presence of a novel O allele.</p>

Ael subgroup due to alpha-1,3-N-acetylgalactoseaminotransferase gene 467C>T and 804insG variants / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the effect of variants of alpha-1,3-N-acetylgalactosaminyltransferase of the ABO gene on A antigen expression.</p><p><b>METHODS</b>Three samples were assayed by serological method. The extracted DNA was genotyped by sequence-specific primer polymerase chain reaction (SSP-PCR) and direct sequencing. To identify haploid of the ABO gene, clones for exons 6 and 7 of the ABO locus were analyzed.</p><p><b>RESULTS</b>All of the three samples were identified as the Ael subgroup, among which were found to carry the Ael08 and O01 alleles, while another was confirmed to harbor the Ael08 and O04 alleles. Compared with the A101 allele, two nucleotide alterations (467C>T and 804insG) at exon 7 have resulted in amino acid substitution P156L and frameshift from position 269.</p><p><b>CONCLUSION</b>467C>T and 804insG variants of the alpha-1,3-N-acetylgalactosaminyltransferase gene probably underlie the Ael phenotype.</p>

Molecular genetic analysis of an Ax13B phenotype of ABO subtype / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the molecular basis for a rare Ax13B phenotype of the ABO subtype.</p><p><b>METHODS</b>Serological assays were carried out to characterize the erythrocyte phenotype of the discrepant sample. Exons 6 and 7 of the ABO gene were amplified with polymerase chain reaction and subjected to direct sequencing. The amplicons were also cloned to separate the two alleles.</p><p><b>RESULTS</b>Both A and B antigens were detected on the red blood cells of the proband, and anti-A antibody was detected in the serum. The serological phenotype of the sample was identified as AxB. DNA sequencing showed heterozygous status for 297AG, 526CG, 657CT, 703AG, 796AC, 803GC, 930GA and 940AG in exons 6 and 7. After cloning and sequencing, two alleles Ax13 and B101 were obtained. The sequence of Ax13 showed a nucleotide change (A to G) at position 940.</p><p><b>CONCLUSION</b>The 940A>G mutation of the α-1,3-N-acetylgalactosaminyltransferase gene has resulted in the reduced expression of A antigen.</p>

Identification of a novel T421C mutation of α-1,3-N-acetylgalactosaminyltransferase allele responsible for an A variant / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the molecular basis of an individual featuring weak A phenotype of ABO blood group system.</p><p><b>METHODS</b>Serologic investigations, serum transferases activity assay and absorption-elution test were carried out to identify the ABO blood group. The 7 exons and flanking introns of ABO glycosyltransferase gene were amplified with polymerase chain reaction (PCR). The products were sequenced bidirectinally following enzyme digestion. Haplotypes of exons 6 and 7 of the ABO gene were analyzed.</p><p><b>RESULTS</b>A weak A antigen was identified on red blood cells of the proband. Eight heterozygous sites in exons 6 and 7 (261delG 297A/G, 421C/T, 467C/T, 646T/A, 681G/A, 771C/T, 829G/A) of the ABO gene were identified. Based on haplotype analysis, one allele was determined as O02, while a novel mutation 421T>C was identified in another allele, which resulted in the amino acid change Ser141Pro of the A glycosyltransferase.</p><p><b>CONCLUSION</b>Above results suggested that amino acid substitutions resulted from a novel mutation 421T>C of the ABO gene may decrease the enzymatic activity and result in the weak A phenotype.</p>

A rare Pk phenotype caused by a 433 C>T mutation of the β-1,3-N-acetylgalactosyltransferase gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the serological characteristics and molecular mechanism for a rare Pk phenotype of the P1Pk blood group system.</p><p><b>METHODS</b>The blood group of the proband was identified by serological techniques. The coding region and flanking intronic sequences of the β-1,3-N-acetylgalactosyltransferase gene (B3GALANT1) associated with the Pk phenotype were analyzed using polymerase chain reaction sequence-based typing.</p><p><b>RESULTS</b>The proband was identified as having a rare Pk phenotype including anti-P in her serum. The blood group of her daughter and husband showed a P2 phenotype. The nucleotide sequences of the B3GALANT1 gene of her husband and two randomly-chosen individuals were the same as the reference sequence (GenBank AB050855). Nucleotide position 433 C>T homozygous mutation in the B3GALANT1 was found in the proband, which has resulted in a stop codon at amino acid position 145, which may produce a premature protein capable of decreasing or inhibiting the activity of the β -1,3-N-acetylgalactosyltransferase. The nucleotide position 433 C/T heterozygous in the B3GALANT1 was found in her daughter.</p><p><b>CONCLUSION</b>The Pk phenotype resulted from 433 C>T mutation in the B3GALANT1 gene has been identified.</p>

A A311 blood group gene subtype caused by a-1-3-N-acetylgalactosaminyltransferase gene exon 7 mutations / 中国实验血液学杂志

This study was purposed to analyses the serological and molecular basis of one sample of A blood group which has anti-A. The tube method was used to detect the blood group phenotype, the genotype was amplified by PCR-SSP. The sequence of a-1-3-N-acetylgalactosaminyltransferase gene of blood group was determined by Sanger method. The results showed that serological results of blood group were discrepant. It was determined as A subtype firstly. The result of PCR-SSP showed the existence of O and A blood group gene. The sequencing result of the 6th exon of ABO gene showed the existence of c.261delG, which refers to the O gene. The specific amplification sequencing analysis was carried out on the 7th exon of the O and A blood group gene. Two mutations in the 7th exon of the A gene haplotype, c.467 C > T and c.626 G > A, four mutations in the 7th exon of the O gene haplotype, c.646T > A, 681G > A, 771C > T, 829G > A had been detected. It is concluded that a novel allelic mutation c.626 G > A in the 7th exon of A gene is explored. The Genbank access number of this novel mutation is KC690281. c.467 C > T is SNP. The combination of two allele mutation of A gene is named as a new allelic subtype A311.

C742T mutation of α1, 3 N-acetyl-D-galactosaminyltransferase gene is responsible for A2 subgroup / 中国实验血液学杂志

The objective of this study was to analyze the molecular genetic basis for 2 individuals with A2B phenotype of ABO subtype. The ABO group antigens on red blood cells were identified by monoclonal antibodies and the ABO antibodies in serum were detected by the standard A, B, O cells. The exon 5 to exon 7 coding region of ABO gene was amplified by polymerase chain reaction (PCR) and the PCR product was sequenced directly after the enzymes digested. The amplified product was also cloned by TOPO TA cloning sequencing kit to split the 2 alleles apart and chosen colonies were sequencing bidirectionally for exon 6 to 7 of ABO gene. The results showed that both A and B antigen were identified on red blood cells of the individuals and there was anti-A1 antibody in their serum. There was no 261G deletion and showed 297A/G, 467C/T, 526C/G, 657C/T, 703G/A, 742C/T, 796C/A, 803G/C, 930G/A heterozygotes by direct DNA sequencing. After cloning and sequencing, it was obtained the B101 and one novel A allele. The novel allele has one nucleotide change at 742 position C to T compared with A102, which results in an amino acid Arg to Cys at 248 position and was nominated as A213. It is concluded that C742T mutation of the α1, 3 N-acetyl-D-galactosaminyl-transferase gene can lead to A2 phenotype and with anti-A1 antibody in serum.