OBJECTIVE: To detect loss of heterozygosity (LOH) at human leukocyte antigen (HLA) loci in a Chinese patient with leukemia after haploidentical hematopoietic stem cell transplantation. METHODS: HLA genotyping was carried out on peripheral blood, hair follicle and buccal swab samples derived from the patient after the transplantation as well as peripheral blood samples from his parents by using PCR-sequence specific oligonucleotide probe method and PCR-sequence based typing method. Short tandem repeat (STR) loci were detected by using a 23 site STR assay kit and a self-developed 6 STR loci assay for the HLA regions. RESULTS: After the transplantation, the HLA genotype of the peripheral blood sample of the patient was identical to his father. The patient was HLA-A*02:01,24:02, C*03:03,03:04, B*13:01,15:01, DRB1*08:03,12:02, DQB1*03:01,06:01 for his hair follicle specimen. However, homozygosity of the HLA loci was found in his buccal swab sample. Only the HLA-A*24:02-C*03:03-B*15:01-DRB1*08:03-DQB1*06:01 haplotype from his father's was present, while the HLA-A*02:01-C*03:04-B*13:01-DRB1*12:02-DQB1*03:01 haplotype from his mother was lost. After the transplantation, the alleles of the 23 STR sites in the patient's peripheral blood sample were consistent to his father, with no allelic loss detected in his buccal swab sample. However, at least 4 STR loci in the HLA region were lost in his buccal swab sample. CONCLUSION LOH at the HLA loci has been detected in the buccal swab sample of a patient with leukemia who received haploidentical hematopoietic stem cell transplantation.
HLA Antigens/genetics* ; HLA-A Antigens/genetics* ; Histocompatibility Antigens Class I/genetics* ; Humans ; Leukemia/genetics* ; Loss of Heterozygosity

OBJECTIVES: To observe and analyse the Amelogenin allelic loss in parent-child identification cases, and to explore the type and mechanism of Amelogenin allelic loss as well as its influence on gender identification and solutions. METHODS: After the detection by SiFaSTR™ 23plex DNA identification system, samples had the characteristics of the peak area of Amelogenin X was the same as the one of adjacent heterozygote or lower than one half of adjacent homozygote in females while Amelogenin X loss was observed in males were selected. X chromosome STR （X-STR） typing and Amelogenin X sequencing were performed. The samples with Amelogenin Y loss in males were confirmed by the detection of Y chromosome STR typing and sex-determining region of Y （SRY）. The type and rate of Amelogenin allelic loss were confirmed and calculated, and the mechanism and influence of this variation were also analysed. RESULTS: Amelogenin X allelic loss was observed in one male sample, the mutation in primer-binding region was confirmed by sequencing. The suspected Amelogenin X allelic loss was observed in four female samples, but the mutation in primer-binding region was confirmed by sequencing in only one sample. Amelogenin Y allelic loss was observed in seven male samples, SRY positive cases was detected in five of them, and two were SRY negative. Y-STR type was detected in four cases of the five SRY positive cases, which was not detected in the two SRY negative cases. The rate of Amelogenin allelic loss was about 0.029%. CONCLUSIONS Amelogenin X allelic loss does not affect the gender identification, but Amelogenin Y allelic loss may cause wrong gender identification. Thus, Y-STR or SRY should be detected for gender confirmation. When Y-STR genotypes are not detected in a "male" whose SRY detection is also negative, then the chromosome karyotype analysis and sex differentiation related genes test should be taken to further confirm the gender.
Amelogenin/genetics* ; DNA/genetics* ; Female ; Humans ; Loss of Heterozygosity/genetics* ; Male ; Sex Determination Analysis

Loss of heterozygosity (LOH) has been established as an important genetic mechanism giving rise to malignant neoplasia. The mechanism of LOH has been shown to cause basal cell carcinoma and malignant melanoma as well as other types of skin cancer. A few studies on LOH in sporadic keratoacanthomas have been reported. The purpose of this study was to investigate the significance of LOH in the pathogenesis of sporadic keratoacanthomas developed in 10 Korean patients. The presents of LOH at 7 microsatellite markers (D2S286, D3S1317, D5S346, D9S160, D9S171, D10S185, and D17S261) were evaluated in sporadic keratoacanthomas. LOH was found in only 1 of 10 cases at D10S185. The low frequency of LOH detected in this study suggests that LOH may not be significant in the induction of sporadic keratoacanthomas.
Adult ; Aged ; Female ; Humans ; Keratoacanthoma/*genetics ; *Loss of Heterozygosity ; Male ; Middle Aged ; Research Support, Non-U.S. Gov't

OBJECTIVE: To assess the diagnostic value of whole exome sequencing (WES) for patients with intellectual disability (ID) or global developmental delay (GDD). METHODS: 134 individuals with ID or GDD who presented at Chenzhou First People's Hospital between May 2018 and December 2021 were selected as the study subjects. WES was carried out on peripheral blood samples of the patients and their parents, and candidate variants were verified by Sanger sequencing, copy number variation sequencing (CNV-seq) and co-segregation analysis. The pathogenicity of the variants was predicted based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). RESULTS: A total of 46 pathogenic single nucleotide variants (SNVs) and small insertion/deletion (InDel) variants, 11 pathogenic genomic copy number variants (CNVs), and 1 uniparental diploidy (UPD) were detected, which yielded an overall detection rate of 43.28% (58/134). The 46 pathogenic SNV/InDel have involved 62 mutation sites in 40 genes, among which MECP2 was the most frequent (n = 4). The 11 pathogenic CNVs have included 10 deletions and 1 duplication, which have ranged from 0.76 to 15.02 Mb. A loss of heterozygosity (LOH) region of approximately 15.62 Mb was detected in 15q11.2q12 region in a patient, which was validated as paternal UPD based on the result of trio-WES. The patient was ultimately diagnosed as Angelman syndrome. CONCLUSION WES can detect not only SNV/InDel, but also CNV and LOH. By integrating family data, WES can accurately determine the origin of the variants and provide a useful tool for uncovering the genetic etiology of patients with ID or GDD.
Humans ; Exome Sequencing ; Intellectual Disability/genetics* ; DNA Copy Number Variations ; Mutation ; Loss of Heterozygosity

OBJECTIVETo reveal the molecular genetic mechanisms for the pathogenesis of glioblastoma (GBM) and determine which chromosomes or chromosomal regions may play a role in the pathogenesis of GBM or may harbor tumor suppressor genes (TSGs) associated GBM.

METHODSAn allelotype study of 21 cases of GBM was performed by polymerase chain reaction and loss of heterozygosity (LOH) analysis. Three hundred and eighty-two microsatellite markers covering all 22 autosomes were used. The mean genetic distance between two flanking markers is about 10 cM. Fluorescent dye-labeled primers and Perkin Elmer 377 DNA Sequencer were applied.

RESULTSLOH was observed on all chromosomal arms examined in this study. The LOH frequencies of 10q, 10p, 13q, 17p and 9p were the highest (>50%), on which high LOH frequencies were detected at the regions resided by the known TSGs including PTEN, DMBT1, p16, p15, p53 and Rb. The following commonly deleted regions were detected: 9p22-23, 10p12.2-14, 10q21.3, 13q12.1-14.1, 13q14.3-31, 17p11.2-12, 17p13, 3q24-27, 11p12-13, 14q31-32.3, 14q21-24.1, 22q13.2-13.3, 4q35, 4q31.1-31.2, 6qtel, 6q16.3.

CONCLUSIONThis study demonstrated that the pathogenesis of GBM is very complicated and associated with various molecular genetic abnormalities on lots of chromosomes. The chromosomal arms most closely relevant to the pathogenesis of GBM are 10q, 10p, 9p, 17p and 13q. Besides the well-known TSGs, such as PTEN, DMBT1, p16, p15, p53 and Rb, multiple unknown TSGs associated with GBM may be present on the commonly deleted regions observed for the first time in this study.

Adult ; Aged ; Chromosomes, Human ; genetics ; DNA, Neoplasm ; genetics ; Female ; Glioblastoma ; genetics ; Humans ; Loss of Heterozygosity ; Male ; Microsatellite Repeats ; Middle Aged

OBJECTIVETo investigate common chromosomal changes and the LOH frequency of microsatellite loci in primary gastric cancer samples in order to locate the deleted regions in which human gastric cancer related genes might exist.

METHODSComparative genomic hybridization (CGH) was used to define global chromosomal aberrations in 43 primary gastric tumors. Based on the results of CGH, analysis of loss of heterozygosity (LOH) was performed in chromosome 19 in which the loss was first discovered in the gastric cancers. The PCR-based approach was used to investigate 22 loci, which are spaced at 1.1 - 10.9 cM intervals throughout chromosome 19. The amplified PCR fragments were subjected to electrophoresis in PAGE gel and analyzed with Genescan trade mark and Genotyper trade mark.

RESULTSCGH analysis revealed gains in chromosome 3p (8/43), 8q (8/43), 20 [20 (9/43), 20p (7/43), 20q (4/43)], 12q (16/43), 13q (12/43) and losses in 19 [19 (15/43)], 7 [17 (8/43), 17p (10/43)], 16 (10/43) and 1p (11/43). Among the 43 evaluated samples, the most frequent LOH was detected at locus D19S571 (27.81%).

CONCLUSIONSThe tumorigenesis of gastric cancer includes several chromosomal changes. The aberration of chromosome 19 was the first common change founded in gastric cancer. The region near the D19S571 might harbor potential genes related to the tumorigenesis of gastric cancer.

Chromosomes, Human, Pair 19 ; Humans ; Loss of Heterozygosity ; Nucleic Acid Hybridization ; Peutz-Jeghers Syndrome ; genetics ; Stomach Neoplasms ; genetics

OBJECTIVE: To examine the microsatellite instability and loss of heterozygosity in the pathogenic mechanism of laryngeal squamous cell carcinomas. METHOD: Forty cases squamous cell carcinomas of larynx were analyzed by comparing tumorous tissues and normal tissues around with 3 microsatellite markers from chromosome 3, 5 and 11, using PCR and PGE-AgNO3 staining. RESULT: Among the 40 cases of laryngeal squamous cell carcinomas, 87.5% (35/40) of samples showed microsatellite instability or loss of heterozygosity in one to three microsatellite markers. High frequent microsatellite abnormal occurred at D5S592, it was 70% (28/40). Then the mutation rate of D3s1228 was 52.5% (21/40). CONCLUSION Our study revealed that tumor suppressor genes nearby chromosome 3p14 and 5q23 regions related to the pathogenesis of squamous cell carcinomas of larynx. A correlation between microsatellite alternation and stage of the tumor were found in D3s1228 and D5s592 chromosome regions.
Carcinoma, Squamous Cell ; genetics ; pathology ; Genes, Tumor Suppressor ; Humans ; Laryngeal Neoplasms ; genetics ; pathology ; Loss of Heterozygosity ; Microsatellite Instability ; Neoplasm Staging

RecQ5 in mammalian cells has been suggested to suppress inappropriate homologous recombination. However, the specific pathway(s) in which it is involved and the underlining mechanism(s) remain poorly understood. We took advantage of genetic tools in Drosophila to investigate how Drosophila RecQ5 (dRecQ5) functions in vivo in homologous recombination-mediated double strand break (DSB) repair. We generated null alleles of dRecQ5 using the targeted recombination technique. The mutant animals are homozygous viable, but with growth retardation during development. The mutants are sensitive to both exogenous DSB-inducing treatment, such as gamma-irradiation, and endogenously induced double strand breaks (DSBs) by I-Sce I endonuclease. In the absence of dRecQ5, single strand annealing (SSA)-mediated DSB repair is compromised with compensatory increases in either inter-homologous gene conversion, or non-homologous end joining (NHEJ) when inter-chromosomal homologous sequence is unavailable. Loss of function of dRecQ5 also leads to genome instability in loss of heterozygosity (LOH) assays. Together, our data demonstrate that dRecQ5 functions in SSA-mediated DSB repair to achieve its full efficiency and in suppression of LOH in Drosophila.
Animals ; DNA Repair ; genetics ; DNA, Single-Stranded ; genetics ; Drosophila Proteins ; genetics ; metabolism ; Drosophila melanogaster ; genetics ; metabolism ; Loss of Heterozygosity ; genetics ; RecQ Helicases ; genetics ; metabolism

OBJECTIVETo evaluate whether deletion of chromosome 14q is involved in the carcinogenesis of primary glioblastoma multiforme and to identify possibly common deletion regions. METHJODS: Fourteen fluorescent dye-labeled polymorphic markers were used and polymerase chain reaction-based microsatellite analysis was employed to investigate loss of heterozygosity (LOH) on chromosome 14q in 20 primary glioblastoma multiforme (GBM).

RESULTSTen of twenty (50%) GBM displayed LOH at one or more of the markers on chromosome 14q. Five tumors showed either LOH or non-informative on all markers tested. The most frequent LOH was observed at locus D14S65 (57.1%) on 14q32.1, and in the chromosomal region spanning from D14S63 (47.1%) to D14S74 (46.7%) on 14q23-31. None of the informative loci exhibited microsatellite instability.

CONCLUSIONSAllelic deletion on chromosome 14q plays an important role in the pathogenesis of GBM. Chromosomal regions at locus D14S65 on 14q32.1 and spanning from D14S63 to D14S74 on 14q23-31 may harbor multiple tumor suppressor genes associated with GBM.

Adult ; Aged ; Chromosomes, Human, Pair 14 ; Female ; Genes, Tumor Suppressor ; Glioblastoma ; genetics ; Humans ; Loss of Heterozygosity ; Male ; Microsatellite Repeats ; Middle Aged

OBJECTIVEThe aim of this study was to investigate the loss of heterozygosity (LOH) on chromosome 1 pter-36.21 of keloid in order to locate the deletion areas probably harboring scar suppressor genes.

METHODSUsing polymerase chain reaction ( PCR )-denaturing polyacrylamide gel electrophoresis, 25 samples of keloid tissues and peripheral blood were analyzed.

RESULTS15 out of 25 samples of keloid tissues exhibited LOH in at least one microsatellite locus. There were deletions at more than one locus of one keloid tissue. No MSI was found. The frequency of LOH was remarkably higher in the keloid tissues (n = 25, 15, 60%) than in the normal control samples (n = 25, 1, 4%). The frequency of LOH in D1S243, D1S468, D1S507 and D1S199 was as following: (n= 25, 7, 28%), (n =25, 10, 40%), (n = 25, 13, 52%) and (n= 25, 3, 12%). The frequency of LOH in D1S243, D1S468, D1S507 were statistically significant.

CONCLUSIONThe most common LOH occurred at D1S243-D1S468-D1S507 might imply the existence of potential tumor suppressor gene of a subset of keloid , while MSI on 1 pter-36.21 may not a crucial event.

Adolescent ; Adult ; Chromosome Mapping ; Chromosomes, Human, Pair 1 ; Female ; Humans ; Keloid ; genetics ; Loss of Heterozygosity ; Male ; Middle Aged ; Young Adult