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1.

Background

An inherited germline P53 mutation has been identified in cases of childhood adrenocortical carcinoma (ACT), a neoplasm with a high incidence in southern Brazil. The penetrance of ACT in carriers of the point mutation, which encodes an arginine‐to‐histidine substitution at codon 337 of TP53 (R337H), has not been determined.

Objective

To investigate the penetrance of childhood ACT in carriers of the R337H TP53 mutation.

Methods

The family histories of 30 kindreds of 41 southern Brazilian children with ACT were obtained. A PCR based assay was used to detect this P53 mutation in a large number of relatives of children with ACT. In all, 927 individuals were tested for the mutation, 232 from the non‐carrier and 695 (including the 40 probands) from the carrier parental lines.

Results

40 children with ACT carried the TP53 R337H mutation; the remaining child with ACT was not tested. There was no evidence of Li‐Fraumeni syndrome in any of the kindreds; however, seven met the criteria for Li‐Fraumeni‐like syndrome. The carrier parental line was identified in each kindred. Of the 695 individuals tested in the carrier parental line, 240 (34.5%) were positive for the mutation, while none of the 232 individuals in the other parental line carried the mutation. The penetrance of ACT was 9.9% (95% confidence interval, 8.7% to 11.1%).

Conclusions

The TP53 R337H mutation dramatically increases predisposition to childhood ACT but not to other cancers, and explains the increased frequency of ACT observed in this geographic region.  相似文献   

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3.
The mutational spectrum for the TP53 gene was investigated in a large series of bladder tumors and bladder tumor cell lines. Tumors and cell lines were screened for the presence of TP53 point mutations by single-strand conformational polymorphism analysis followed by direct sequencing. Mutations were detected in 16 of 88 (18%) tumors and 4 of 14 cell lines (28%). In total, twelve missense mutations, one nonsense mutation, three deletions, and two insertions were identified by direct sequencing. Of the thirteen point mutations sequenced, only one was a transition at a CpG site, whereas five G:C → T:A transversions were found, suggesting a major role for exogenous mutagens in bladder tumorigenesis. Tumors were also examined for loss of heterozygosity (LOH) on chromosome arm 17p. LOH of one or more markers on 17p was detected in 31 % of tumors. All eight tumors with a TP53 mutation from patients informative at TP53 had LOH, whereas nine tumors with LOH at TP53 did not have an identified mutation. Three tumors had LOH on 17p at sites distal to the TP53 locus but retained both TP53 alleles, suggesting the involvement of another tumor suppressor gene on 17p in bladder tumorigenesis in some tumors. Genes Chrom Cancer 9:108-118 (1994).© 1994 Wiley-Liss, Inc.  相似文献   

4.
Cells with abnormal TP53 lose cell cycle checkpoints, resulting in genomic instability and neoplastic transformation. However, the evidence linking the tumor-specific targets of genomic alteration to an abnormal TP53 is limited. The present study tested the hypothesis that TP53 abnormalities are correlated with an increased frequency of deletion of breast cancer susceptibility loci (17q and 13q) in breast carcinomas. Tumors from 90 patients were examined for TP53 abnormality and loss of heterozygosity (LOH) at 11 loci on 17q (17q11.2–21) and 13q (13q12–14), including the loci for BRCA1 and BRCA2. A higher frequency of LOH was consistently found at 17q or 13q loci in tumors with an abnormal TP53. The increased LOH in relation to TP53 abnormality was statistically significant at the BRCA1, D17S588, and D13S267 loci (P < 0.05) but not at the locus for BRCA2 (P = 0.64). These observations imply a possible link between an abnormal TP53 and specific genomic deletions of breast cancer susceptibility loci, which may provide clues to the role of TP53 during breast tumorigenesis. Genes Chromosomes Cancer 20:377–382, 1997. © 1997 Wiley-Liss, Inc.  相似文献   

5.
Chromosome 22q loss of heterozygosity (LOH) is the most common allelic loss in benign meningioma and is thought to be the earliest initiating event in meningioma formation. We used published data and logistic regression to evaluate the association of 22q LOH with age at diagnosis in 318 transitional, fibroblastic, and meningothelial meningiomas. After adjustment for anatomical location, the odds ratio of 22q LOH per year of age was >1 in each histological type of meningioma, and was significantly >1 in transitional and fibroblastic meningioma. This finding is compatible with involvement of the neurofibromatosis 2 tumour suppressor gene, NF2, on chromosome 22q in the high incidence of benign meningioma in the elderly.  相似文献   

6.
Nephrogenic rests are precursor lesions associated with about 40% of Wilms’ tumors. This study identifies genetic steps occurring in the development of Wilms’ tumor. Thirty-four Wilms’ tumors with nephrogenic rests and/or areas of anaplasia were microdissected from paraffin sections to determine whether and at what stage loss of heterozygosity (LOH) occurred, using polymerase chain reaction-based polymorphic markers at 11p13, 11p15, and 16q. LOH at these loci have been identified in Wilms’ tumors and are associated with identified or putative tumor suppressor genes. Three cystic nephromas/cystic partially differentiated nephroblastomas were also examined. LOH was detected in six cases at 11p13 and in six cases at 11p15, and two of these cases had LOH at both loci. All intralobar rests showing LOH also showed LOH in the tumor. A case with a small perilobar rest showed LOH of 11p13 only in the tumor. Five cases showing LOH at 16q were identified (this was identified only in the tumor, and not in the associated rest), and three of these had recurrence of the tumor. Two cases had a WT1 mutation (one germline and the other somatic), as well as LOH in both the intralobar rest and the tumor. A cystic partially differentiated nephroblastoma showed loss at 11p13 and 11p15, as well as at 16q. This study suggests that LOH at 11p13 and 11p15 and WT1 mutations are early events but that LOH at 16q occurs late in the pathogenesis of Wilms’ tumor. Intralobar and perilobar nephrogenic rests are known to have different biological behaviors, and this study suggests that they are genetically different. A multistep model of Wilms’ tumor pathogenesis is supported by these findings.  相似文献   

7.
Ample molecular data are available on the progression from normal mucosa to invasive head and neck squamous cell carcinoma (HNSCC), but information on further genetic progression to metastatic disease is scarce. To obtain insight into the metastatic process, we compared 23 primary HNSCCs with 25 corresponding lymph node metastases (LNMs) and 10 corresponding distant metastases (DMs) with respect to TP53 mutations and patterns of loss of heterozygosity (LOH) based on 26 microsatellite markers on six chromosome arms (3p, 9p, 17p, 13q, 8p, and 18q). In 18 of the 23 patients, a TP53 mutation was detected in the primary tumor, and in all cases the same TP53 mutation was present in the corresponding LNM or DM. In nine of 20 patients with LNMs and three of seven patients with DMs, the LOH pattern of metastasis differed from that of the corresponding primary tumor by at least one marker. Microsatellite markers located on chromosome arms 13q, 8p, and 18q were most frequently discordant, providing evidence that alterations at these chromosomes occur late in HNSCC carcinogenesis. Moreover, evidence was found that DMs had developed directly from the primary tumor and not from LNMs. Remarkably, we observed that the mutational status of the TP53 gene is associated significantly with the degree of genetic differences between primary HNSCCs and corresponding metastases. All patients with TP53 wild-type primary tumors showed significantly more discordant LOH patterns in the corresponding LNMs and DMs than patients with TP53-mutated tumors. The percentages were 100% versus 27% (LNMs) and 100% versus 0% (DMs), respectively (P = 0.008 and P = 0.029; two-sided Fisher exact test). This finding suggests that TP53-mutated tumors need fewer additional genetic alterations to develop metastases compared with TP53 wild-type primary tumors.  相似文献   

8.
Autosomal-dominant idiopathic infantile nystagmus has been linked to 6p12 (OMIM 164100), 7p11.2 (OMIM 608345) and 13q31-q33 (OMIM 193003). PAX6 (11p13, OMIM 607108) mutations can also cause autosomal-dominant nystagmus, typically in association with aniridia or iris hypoplasia. We studied a large multigenerational white British family with autosomal-dominant nystagmus, normal irides and presenile cataracts. An SNP-based genome-wide analysis revealed a linkage to a 13.4-MB region on chromosome 11p13 with a maximum lod score of 2.93. A mutation analysis of the entire coding region and splice junctions of the PAX6 gene revealed a novel heterozygous missense mutation (c.227C>G) that segregated with the phenotype and is predicted to result in the amino-acid substitution of proline by arginine at codon 76 p.(P76R). The amino-acid variation p.(P76R) within the paired box domain is likely to destabilise the protein due to steric hindrance as a result of the introduction of a polar and larger amino acid. Eye movement recordings showed a significant intrafamilial variability of horizontal, vertical and torsional nystagmus. High-resolution in vivo imaging of the retina using optical coherence tomography (OCT) revealed features of foveal hypoplasia, including rudimentary foveal pit, incursion of inner retinal layers, short photoreceptor outer segments and optic nerve hypoplasia. Thus, this study presents a family that segregates a PAX6 mutation with nystagmus and foveal hypoplasia in the absence of iris abnormalities. Moreover, it is the first study showing detailed characteristics using eye movement recordings of autosomal-dominant nystagmus in a multigenerational family with a novel PAX6 mutation.  相似文献   

9.
Chromosomal losses involving the short arm of chromosome 8 are frequent in a variety of tumour types, including breast cancer, suggesting the presence of one or more tumour suppressor genes in this region. In this study, we have used 11 microsatellite markers to analyse loss of heterozygosity (LOH) at chromosome 8p in 151 sporadic breast tumours and 50 tumours from subjects carrying the BRCA2 999del5 mutation. Fifty percent of sporadic tumours compared to 78% of BRCA2 linked tumours exhibit LOH at one or more markers at 8p showing that chromosome 8p alterations in breast tumours from BRCA2 999del5 carriers are more pronounced than in sporadic breast tumours. The pattern of LOH is different in the two groups and a higher proportion of BRCA2 tumours have LOH in a large region of chromosome 8p. In the total patient material, LOH of 8p is associated with LOH at other chromosome regions, for example, 1p, 3p, 6q, 7q, 9p, 11p, 13q, 17p, and 20q, but no association is found between LOH at 8p and chromosome regions 11q, 16q, 17q, and 18q. Furthermore, an association is detected between LOH at 8p and positive node status, large tumour size, aneuploidy, and high S phase fraction. Breast cancer patients with LOH at chromosome 8p have a worse prognosis than patients without this defect. Multivariate analysis suggests that LOH at 8p is an independent prognostic factor. We conclude that chromosome 8p carries a tumour suppressor gene or genes, the loss of which results in growth advantage of breast tumour cells, especially in carriers of the BRCA2 999del5 mutation.


Keywords: chromosome 8; BRCA2; LOH; breast cancer  相似文献   

10.
Recent studies have shown that Th17 cells may be involved in the pathological process of acute myeloid leukemia. This CD4+ cell subgroup secretes highly homologous interleukin (IL)-17A and IL-17F, and also expresses IL-23 receptor (IL-23R) on the cell surface. Our study aims to investigate the relationship of IL-17A, IL-17F, and IL23R with disease susceptibility, and clarify the relationship between gene polymorphism variation and serum IL-17 level. 62 acute myeloid leukemia patients and 125 healthy controls were included in this study. Restriction fragment length polymorphism polymerase chain reaction (PCR-RFLP) was applied to analyze IL-17A (rs2275913; G-197A), IL17F (rs763780; A7488G; His161Arg), and IL-23R (rs11209026, G1142A; Arg381Gln) alleles. At the same time, enzyme-linked immunoassay analysis (ELISA) was used to test serum IL-17 level in patients. Acute myeloid leukemia patients presented higher rate of IL-17F G single mutant (RR = 4.75, P < 0.001) and GG mutation homozygote (RR = 23.01, P < 0.005). While IL-17A, IL-23R A single mutant and purified AA mutation homozygote showed no correlation with acute myeloid leukemia susceptibility. In addition, ELISA showed that serum IL-17 exhibited no significant difference between acute myeloid leukemia patients and healthy controls had (8.8 ± 7.19 pg/ml vs. 1.4 ± 0.2 pg/ml, P > 0.05). IL-17F G single mutant and GG mutation homozygote were correlated with acute myeloid leukemia susceptibility, while IL-17 gene polymorphism and serum IL-17 level were not. Furthermore, IL-17A and IL-23R gene polymorphism were not associated with acute myeloid leukemia susceptibility.  相似文献   

11.
We examined 88 nonpapillary renal cell carcinomas for allelic loss at chromosome arm 14q and correlated the results to size, grade, and stage of these tumors. Fourteen highly polymorphic microsatellite markers on the long arm of chromosome 14 were used for deletion mapping. Loss of heterozygosity (LOH) at the smallest overlapping segment of 14q24.2-qter was seen in 42 of 88 tumors. There was no significant correlation between frequency of 14q LOH and size of tumors (P = 0.11). LOH was frequently seen in grade 2 and 3 tumors (55% and 73%, respectively) and in stage III and IV tumors (53% and 80%, respectively). We found a significant correlation between chromosome arm 14q LOH and nuclear grade (P < 0.001) and stage (P < 0.001) of tumors. These observations indicate the presence of a tumor-suppressor gene at chromosome segment 14q24.2-qter and demonstrate the usefulness of microsatellite analysis for assessing the possible clinical outcome of nonpapillary renal cell carcinomas. Genes Chromosom. Cancer 19:29–35, 1997. © 1997 Wiley-Liss, Inc.  相似文献   

12.
A tumor suppressor gene at 10q23.3, designated PTEN, encoding a dual-specificity phosphatase with lipid and protein phosphatase activity, has been shown to play an essential role in the pathogenesis of a variety of human cancers. Frequent mutations and deletions of PTEN genes are found in cancer. Little is known, however, about the role that PTEN plays in the pathogenesis of a primary choriocarcinoma derived from gastric adenocarcinoma, an extremely rare choriocarcinoma, or in extragonadal retroperitoneal choriocarcinoma. In this study, genetic alterations occurring in extragonadal choriocarcinoma in two Japanese male patients were examined. Loss of heterozygosity (LOH) analysis using a polymorphic marker of the PTEN gene, IVS4 + 109ins/delTCTTA, revealed a hemizygous deletion of PTEN not only in the primary gastric choriocarcinoma, but also in the gastric adenocarcinoma. Microsatellite marker D12S1051 likewise showed LOH in both the primary gastric choriocarcinoma and the gastric adenocarcinoma. Mutational analysis of the TP53 gene revealed a point mutation in exon 5 (A536G), which resulted in H179R in the gastric choriocarcinoma but not in the gastric adenocarcinoma. No LOH was found for PTEN in an extragonadal retroperitoneal choriocarcinoma. Microsatellite marker D9S162 showed LOH in the extragonadal retroperitoneal choriocarcinoma, but not in the primary gastric choriocarcinoma. These results indicate that LOH of the PTEN gene and of D12S1051 is the molecular pathogenesis of the gastric adenocarcinoma, and the mutation of the TP53 gene is an additional hit for the oncogenesis of choriocarcinoma arising from gastric adenocarcinoma. However, LOH of the PTEN gene is not a common molecular event for pathogenesis of extragonadal choriocarcinoma. In addition, it was found that expression of PTEN is significantly decreased in the nuclei of syncytiotrophoblast-like cancer cells, compared with those of cytotrophoblast-like cancer cells in choriocarcinoma.  相似文献   

13.
Genetic changes underlying the tumorigenesis of sporadic adrenocortical tumors are poorly characterized. To search for characteristic genomic imbalances involved in adrenocortical tumors, we examined 41 adrenocortical lesions (12 carcinomas, 23 adenomas, and 6 hyperplasias) by comparative genomic hybridization. Our results show that genetic alterations are more frequent in malignant than in benign lesions and that they rarely occur in hyperplastic lesions. The most frequent DNA copy number changes in adrenocortical carcinomas included losses of 1p21-31, 2q, 3p, 3q, 6q, 9p, and 11q14-qter, as well as gains and amplifications of 5q12, 9q32-qter, 12q, and 20q. The genomic aberrations prevalently occurring in adrenocortical adenomas were gains of 17q, 17p, and 9q32-qter. Gains found in 2 of 6 adrenocortical hyperplastic lesions involved chromosome 17 or 17q only. These data indicate that oncogenes determining the early tumorigenesis of adrenocortical tumors may exist on chromosome 17 and that the number of genomic alterations is closely associated with tumor behavior in adrenocortical tumors.  相似文献   

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15.
Due to patterns of migration, selection, and population expansion, founder effects are common among humans. In Southern Brazil, a recurrent TP53 mutation, p.R337H, is detected in families with cancer predisposition. We have used whole locus resequencing and high‐density single nucleotide polymorphism (SNP) genotyping to refine TP53 locus haplotype definitions. Haplotyping of 12 unrelated p.R337H carriers using a set of 29 tag SNPs, revealed that all subjects carried the same haplotype, and presence of the mutation on this haplotype was confirmed by allele‐specific PCR. The probability that this haplotype occurs independently in all index cases was of 3.1×10?9, demonstrating a founder effect. Analysis of the patterns of 103 tumors diagnosed in 12 families showed that the presence of p.R337H is associated with multiple cancers of the Li‐Fraumeni Syndrome (LFS) spectrum, with relatively low penetrance before the age of 30 but a lifetime risk comparable to classical LFS. The p.R337H families are mostly distributed along a road axis historically known as the main route used by merchants of Portuguese origin in the XVIII and XIX century. This historical circumstance and the relatively low penetrance before the age of 30 may have contributed to the maintenance of this pathogenic mutation in a large, open population. Hum Mutat 30:1–8, 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

16.
Endometrial glandular dysplasia (EmGD) may be a newly defined precursor lesion of uterine papillary serous carcinoma (UPSC) by morphology. In this report, we studied molecular changes present in EmGD by the loss of heterozygosity (LOH) approach using laser capture microdissected tissue samples. Nineteen uteri showing at least 1 focus of EmGD by morphology were selected. These cases were 12 UPSC, 2 clear cell carcinomas, 1 mixed uterine papillary serous and endometrioid carcinoma, 1 uterine carcinosarcoma, 1 serous endometrial intraepithelial carcinoma (EIC), and 2 EmGD involving endometrial polyps. Seven microsatellite polymorphic DNA markers (TP53 at 17p, D1S211, and D1S162 at 1p32, D17S1323 at 17q21, D17S1330 at 17q25, D5S346 at 5q, and D2S123 at 2p) were utilized. A total of 123 laser-captured microdissection samples from 19 cases was studied with LOH method. The frequencies and patterns of LOH were analyzed and compared among benign resting endometrium (RE), EmGD, serous EIC, and UPSC. LOH was observed for at least 1 of the 7 markers in all categories of lesions, EmGD, serous EIC, and UPSC. The frequency of LOH for EmGD ranged from 4.2% to 31.3%; the range for serous EIC was 5.9% to 78.6%; and that for UPSC was 7.7% to 62.5%. The most frequent LOH in the 3 above-cited categories of lesions was identified at 17p (TP53) and 1p (D1S162). The frequency of LOH in EmGD with markers of TP53 and D1S162 was significantly higher than in RE (p < 0.05). With markers of D1S211 and D2S123, LOH in EmGD was higher than RE, approaching to a statistically significant level. Compared with foci of serous EIC and UPSC, however, the rate of LOH in EmGD was significantly lower only with TP53 locus (31.3% vs more than 60%, p < 0.05). The difference of LOH frequency with other chromosomal markers between EmGD and serous EIC/UPSC did not reach a statistically significant level. A significantly high concordant LOH pattern was found between foci of EmGD and serous EIC/UPSC (p = 0.05). We conclude that EmGD frequently shows LOH at multiple chromosomal loci, particularly at 17p and 1p. Significantly high concordant LOH frequency between EmGD and paired serous EIC or UPSC strongly suggests that EmGD is a noncancerous precursor lesion of UPSC, probably also of serous EIC. The clinical significance of EmGD needs further studies.  相似文献   

17.
Barrett's esophagus carries a 30- to 100-fold increased risk of adenocarcinoma, which is thought to develop via a metaplasia-dysplasia-carcinoma progression. A common genetic abnormality detected in Barrett's adenocarcinoma is loss of heterozygosity (LOH) at the sites of known or putative tumor suppressor genes, of which there are at least 9 associated with esophageal adenocarcinoma. The aim of this study was to identify at which histological stage of carcinogenesis LOH at these sites occur. Microdissection of multiple paraffin-embedded tissue blocks from 17 esophagogastrectomy specimens of adenocarcinoma arising in Barrett's esophagus yielded areas of metaplasia, low-, intermediate- and high-grade dysplasia, and carcinoma. LOH analysis of microdissected tissues was performed using a double polymerase chain reaction technique with 11 microsatellite primers shown previously to have LOH in at least 30% of esophageal adenocarcinomas. Identical LOH was detected in premalignant and malignant tissues in 4 of 17 patients, and was located at 5q21-q22 (D5S346 primer), 17p11.1-p12 (TCF2 primer), 17p13.1 (TP53 primer), 18q21.1 (detected in colon cancer tumor suppressor gene [DCC] primer), and 18q23-qter (D18S70 primer). These results suggest that LOH at the sites of the DCC, adenomatous polyposis coli (APC), and TP53 tumor suppressor genes occur before the development of adenocarcinoma in Barrett's esophagus, and so merit further study as potential biomarkers of neoplastic progression in patients with Barrett's esophagus undergoing endoscopic and histological surveillance.  相似文献   

18.
Acromesomelic chondrodysplasias (ACDs) are characterized by disproportionate shortening of the appendicular skeleton, predominantly affecting the middle (forearms and forelegs) and distal segments (hands and feet). Here, we present two consanguineous families with missense (c.157T>C, p.(C53R)) or nonsense (c.657G>A, p.(W219*)) mutations in BMPR1B. Homozygous affected individuals show clinical and radiographic findings consistent with ACD-type Grebe. Functional analysis of the missense mutation C53R revealed that the mutated receptor was partially located at the cell membrane. In contrast to the wild-type receptor, C53R mutation hindered the activation of the receptor by its ligand GDF5, as shown by reporter gene assay. Further, overexpression of the C53R mutation in an in vitro chondrogenesis assay showed no effect on cell differentiation, indicating a loss of function. The nonsense mutation (c.657G>A, p.(W219*)) introduces a premature stop codon, which is predicted to be subject to nonsense-mediated mRNA decay, causing reduced protein translation of the mutant allele. A loss-of-function effect of both mutations causing recessive ACD-type Grebe is further supported by the mild brachydactyly or even non-penetrance of these mutations observed in the heterozygous parents. In contrast, dominant-negative BMPR1B mutations described previously are associated with autosomal-dominant brachydactyly-type A2.  相似文献   

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20.
FGFR3 mutations are frequently mutually exclusive of TP53 mutations in invasive high grade urothelial carcinoma (HGUC) and p53 immunohistochemistry is often used as a surrogate for TP53 mutations. A 10 % staining cut off has been used in HGUC for designation as p53 positive or negative however, a novel contemporary method we have previously proposed (0% or >50 % - abnormal vs. 1–49 % - wild type) has shown significant correlation with oncologic outcome as well. We aimed to compare how a ≥10 % vs. 0 % and ≥ 50 % cut off p53 assessment method correlates with TP53 and FGFR3 mutation status. Tissue microarrays created from three retrospective cohorts (two cystectomy cohorts (cohort A, n = 206 and cohort B, n = 91; one T1 transurethral resection cohort (cohort C, n = 47)) were stained with p53 and scored by two blinded reviewers using both p53 scoring schemes. 50 cases from cohort A were assessed for TP53 and FGFR3 mutation status using next generation sequencing and FGFR3 mutation status was separately assessed in cohorts B and C using SNaPshot methodology. 202 (58.7 %) and 142 (41.3 %) cases showed abnormal and wild type p53 staining, respectively. Using the 10 % cut off, 254 cases were positive (73.8 %) and 90 cases were negative (26.2 %). 27 (14.4 %) and 15 (30 %) assessed cases demonstrated FGFR3 and TP53 mutations, respectively; 19/27 FGFR3 mutated showed a wild type pattern of p53 expression while 15/15 TP53 mutated tumours showed an abnormal pattern of p53 expression. There was a significant correlation between the contemporary p53 scoring scheme and TP53 and FGFR3 mutations (p < 0.0001 and p = 0.002, respectively). Improved sensitivity, specificity, positive predictive value, and negative predictive value for TP53 mutation was also seen compared to the 10 % cut off; specifically, the sensitivity and negative predictive value were 100 %. These findings might be of clinical relevance in the era of precision medicine.  相似文献   

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