Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Germline mutation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources
PubMed2003

Similar contributions of BRCA1 and BRCA2 germline mutations to early-onset breast cancer in Germany.

This study was undertaken to investigate the prevalence of BRCA1 and BRCA2 germline mutations in 91 German patients unselected for family history, who were diagnosed with breast cancer before the age of 41 years. Clinical information and blood samples were obtained from all patients. A comprehensive BRCA1 and BRCA2 mutational analysis was performed using the protein truncation assay and single-strand conformational polymorphism analysis followed by DNA sequencing of variant signals detected by these assays. Five different deleterious germline mutations including four frameshift mutations and one missense mutation were identified, three in BRCA1 (3.3%) and two mutations (2.2%) in BRCA2. Both BRCA2 mutations are novel and might be specific for the German population. An additional BRCA1 missense mutation previously described and classified as an unknown variant was found. This mutation was also detected in two breast cancer patients of family P 328 and not in 140 healthy controls suggesting that it is disease associated. In addition, one common polymorphism and five novel intronic sequence variants with unknown significance were found. Our findings show that mutations in BRCA1 and BRCA2 may contribute similarly to early-onset breast cancer in Germany. Given current constraints on health-care resources, these results support the notion that BRCA1 and BRCA2 mutation screening may have the strongest impact on health-care when targeted to high-risk populations.

Adult↗
PubMed1998

Analysis of recurrent germline mutations in the MEN1 gene encountered in apparently unrelated families.

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder that manifests as varying combinations of tumors of endocrine and other tissues (parathyroids, pancreatic islets, duodenal endocrine cells, the anterior pituitary and others). The MEN1 gene is on chromosome 11q13; it was recently identified by positional cloning. We previously reported 32 different germline mutations in 47 of the 50 familial MEN1 probands studied at the NIH. Eight different germline MEN1 mutations were encountered repeatedly in two or more apparently unrelated families. We analyzed the haplotypes of families with recurrent MEN1 mutations with seven polymorphic markers in the 11q13 region surrounding the MEN1 gene (from D11S1883 to D11S4908). Disease haplotypes were inferred from germline DNA and also from tumors with 11ql3 loss of heterozygosity. Two different disease haplotype cores were shared by apparently unrelated families for two mutations in exon 2 (five families with 416delC and six families with 512delC). These two repeat mutations were associated with the two founder effects that we reported in a prior haplotype analysis. The disease haplotypes for each of the other six repeat mutations (seen twice each) were discordant, suggesting independent origins of these recurrent mutations. Most of the MEN1 germline mutations including all of those recurring independently occur in regions of CpG/CpNpG, short DNA repeats or single nucleotide repeat motifs. In conclusion, recurring germline mutations account for about half of the mutations in North American MEN1 families. They result from either founder effects or independent occurrence of one mutation more than one time.

CpG Islands↗
PubMed2003

[Clinicopathological features of typical and non-typical hereditary non-polyposis colorectal cancer and their germline mutation of hMLH1 and hMSH2].

OBJECTIVE: To study the clinicopathological features of the Chinese hereditary non-polyposis colorectal cancer and its germline mutation of hMLH(1) and hMSH(2). METHODS: Thirteen typical Chinese hereditary non-polyposis colorectal carcinoma (HNPC)C kindreds and 19 non-typical HNPCC families were registered and followed up. The germline mutation of the hMLH(1) and hMSH(2) of 12 index cases of 6 typical and 6 non-typical HNPCC were screened by PCR-SSCP. Samples with abnormal mobility were sequenced directly. RESULTS: The average age of typical HNPCC was 47, no difference existed between sexes. Location of the tumors of typical HNPCC represented 44.7% on the right half colon and non-typical HNPCC 65.8% on the rectum. The rate of the metachronos cancer was 11.5%. The 3-, 5-and 10-year survival rate was 64.0%, 45.3% and 31.2% respectively. Among 12 cases, 8 showed abnormal mobility. Except for an intron polymorphism, six exons abnormalities were found in 5 of 12 proband. Sequencing showed 4 missense, 7 insertion and a nonsense mutations. CONCLUSIONS: Chinese HNPCC is early onset, more common on proximal colon and better prognosis. Mutation of hMSH(2) is dominant in the Chinese typical HNPCC, but mutation of hMLH(1) is more common in the non-typical group.

Adaptor Proteins, Signal Transducing↗
PubMed2006

The von Hippel-Lindau (VHL) germline mutation V84L manifests as early-onset bilateral pheochromocytoma.

Von Hippel-Lindau (VHL) disease is a heritable tumor susceptibility syndrome caused by germline mutations in the VHL gene. The types of tumor that can occur in affected individuals include retinal and central nervous system hemangioblastoma, renal cell carcinoma, pheochromocytoma, and others. The pattern of tumor types that develops in a VHL-affected family defines the clinical subtype (1, 2A, 2B, 2C). Generally, it is difficult to accurately predict an individual's clinical phenotype based on their VHL mutation. However, in a few specific VHL mutations, a strong genotype-phenotype correlation has been established. We report here on the clinical findings in individuals from three unrelated families with a V84L VHL germline mutation, and present follow-up information regarding the only other reported family with this missense mutation. In each of these four families, the major clinical manifestation of VHL disease is multiple early-onset pheochromocytomas (VHL type 2C). This series of eight patients strengthens the correlation between the V84L mutation and the VHL type 2C phenotype, and improves our ability to provide prognostic and management recommendations for similarly affected individuals.

Adolescent↗
PubMed2025

Divergent PTEN-p53 interaction upon DNA damage in a human thyroid organoid model with germline PTEN mutations.

Germline mutations in the tumor suppressor phosphatase and tensin homolog (PTEN) cause PTEN hamartoma tumor syndrome (PHTS). PHTS is characterized by an elevated lifetime risk of differentiated thyroid cancer (DTC), 30 times higher than the general population. However, only 1 in 3 PHTS patients develop DTC, and it remains unknown whether specific PTEN variants are associated with an increased risk of DTC. PTEN antagonizes the phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathway, a frequently affected pathway in sporadic DTC. PTEN also acts as a guardian of the genome by interacting with other tumor suppressors. Here, we report how ionizing radiation, an environmental tumorigenic contributor, modifies the DNA damage response based on the type of germline PTEN variants. We hypothesized that certain PTEN variants associated with DTC create a pro-oncogenic molecular signature upon radiation-induced DNA damage. DTC-associated (PTEN M134R ) or DTC-non-associated (PTEN G132D ) germline PTEN mutant alleles were introduced into a human induced pluripotent cell (hiPSC) line derived from a healthy donor utilizing CRISPR-Cas9 gene editing technology. We determined radiation-induced transcriptomic changes in functional thyroid organoids induced from wild-type and both heterozygous PTEN mutant hiPSCs. Both bulk and single-cell RNA sequencing data indicated that radiation upregulated the p53 network more potently in the thyroid organoids with PTEN WT/G132D than those with PTEN WT/M134R , which could be mediated by AKT-dependent MDM2 inactivation and PTEN-p53 physical interaction. Our data suggest that the lack of p53 pathway activation through PTEN-p53 network interactions explains why PTEN M134R is a DTC-susceptible variant.

Humans↗
PubMed2004

BRCA1 and BRCA2 germline mutations in Korean patients with sporadic breast cancer.

In order to evaluate the role of BRCA1 and BRCA2 germline mutations in Korean patients with sporadic breast cancer, 97 patients with sporadic breast cancer were analyzed for mutations in the BRCA1 and BRCA2 coding regions, by using a combination of fluorescent-conformation sensitive gel electrophoresis (F-CSGE) and direct sequencing. Fifty-five distinct sequence variants were detected, which included three pathogenic truncating mutations, 15 missense mutations, 16 polymorphisms, and 21 intronic variants. Twenty-six of these variants have never been previously reported and may be of Korean-specific origin. Two pathogenic BRCA1 mutations (c.922_924delinsT, c.5445G>A) and one pathogenic BRCA2 mutation (c.2259delT) were observed, and two of these (BRCA1 c.5445G>A and BRCA2 c.2259delT) are novel. The total prevalence of germline pathogenic mutations in BRCA1 and/or BRCA2 in Korean sporadic breast cancer is estimated to be about 3.1%. Considering that the majority of breast cancer cases are sporadic, the present study will be helpful in the evaluation of the need for the genetic screening of germline BRCA mutations in sporadic breast cancer patients. Further study using a larger sample size is required to determine the merits of genetic diagnosis and counseling in breast cancer patients.

Adult↗
PubMed2001

Germline mutations of the gene encoding bone morphogenetic protein receptor 1A in juvenile polyposis.

Juvenile polyposis (JP; OMIM 174900) is an autosomal dominant gastrointestinal hamartomatous polyposis syndrome in which patients are at risk for developing gastrointestinal cancers. Previous studies have demonstrated a locus for JP mapping to 18q21.1 (ref. 3) and germline mutations in the homolog of the gene for mothers against decapentaplegic, Drosophila, (MADH4, also known as SMAD4) in several JP families. However, mutations in MADH4 are only present in a subset of JP cases, and although mutations in the gene for phosphatase and tensin homolog (PTEN) have been described in a few families, undefined genetic heterogeneity remains. Using a genome-wide screen in four JP kindreds without germline mutations in MADH4 or PTEN, we identified linkage with markers from chromosome 10q22-23 (maximum lod score of 4.74, straight theta=0.00). We found no recombinants using markers developed from the vicinity of the gene for bone morphogenetic protein receptor 1A (BMPR1A), a serine-threonine kinase type I receptor involved in bone morphogenetic protein (BMP) signaling. Genomic sequencing of BMPR1A in each of these JP kindreds disclosed germline nonsense mutations in all affected kindred members but not in normal control individuals. These findings indicate involvement of an additional gene in the transforming growth factor-beta (TGF-beta) superfamily in the genesis of JP, and document an unanticipated function for BMP in colonic epithelial growth control.

Adenomatous Polyposis Coli↗
PubMed2006

Germline mutations and polymorphic variants in MMR, E-cadherin and MYH genes associated with familial gastric cancer in Jiangsu of China.

Germline mutations in MSH2, MLH1, E-cadherin and MutY (MYH) genes have been implicated in the occurrence of gastric cancer (GC). Epidemiological investigation was performed by recruiting patients with GC onset during 2002 in Jiangsu province, China. We identified suspected hereditary GC patients based on either the GC family history or GC onset at early ages. We have screened germline variations in 101 suspected hereditary GC patients at the coding sequences of MSH2, MLH1, E-cadherin and MYH genes with polymerase chain reaction-denaturing high-performance liquid chromatography (PCR-DHPLC) analysis and DNA sequencing. The result showed that about 40% of patients carried germline variations, predominantly with missense mutations. Of the variations detected are 2 base pair substitutions, c.53C > T and c.74G > A, which is predicted to generate missense mutations of p.Pro18Leu and p.Gly25Asp, respectively, and occurred at the same allele of MYH gene. The frequency of variant haplotype T/A in patients was higher than that in the control group (p = 0.021, odds ratio [OR] = 4.43, 95% confidence interval [95% CI] = 1.33-14.72). Difference in the frequency of the silent mutation p.Asn751Asn in E-cadherin gene was also found between patients and controls (p = 0.009, OR = 2.54, 95% CI = 1.30-4.95). Moreover, 6 types of variations were detected in MSH2 and MLH1 genes in 14 of 101 patients. Most of them occurred at exon7 of MSH2, frequently c.1168C > T, resulting in mutation of p.Leu390Phe. In summary, germline mutation at MSH2, MLH1, E-cadherin and MYH genes is a frequent event in the familial GC. They may form a genetic basis for the familial GC susceptibility in Chinese population.

Adaptor Proteins, Signal Transducing↗
PubMed2003

BRCA2 germline mutations in Cypriot patients with familial breast/ovarian cancer.

Germline mutations in the BRCA2 gene have been shown to be associated with familial female and male breast cancer. Mutations occur throughout the entire coding region of the gene, and there is considerable ethnic and geographical diversity in the deleterious mutations detected in different populations. No data exist on the role of the BRCA2 gene in the Cypriot population. In this study we present the results of characterizing mutations in the BRCA2 gene, in 26 Cypriot families with multiple cases of breast/ovarian cancer. The entire coding region, including splice sites, of BRCA2 were sequenced using cycle sequencing. In total 29 BRCA2 variants were detected which include 3 truncating mutations, 8 missense mutations, 6 polymorphisms and 12 intronic variants. The 3 truncating mutations are frameshift mutation 8984delG (exon 22), and two nonsense mutations, namely C1913X (exon 11) which is a novel mutation, and K3326X (exon 27). It is of interest that frameshift mutation 8984delG was the most frequent, since it was detected in 5 patients from three different families. Among the 6 polymorphisms detected, polymorphism T77T is novel and similarly 4 of the 12 intronic variants were also novel, namely IVS1+8G>A, IVS1-96insA, IVS4+36A>G and IVS11-51G>T. These results show that deleterious BRCA2 mutations, occur at the same frequency, about 20%, in Cypriot families, as that recorded in other European populations. We conclude that the BRCA2 gene plays a significant role in the familial breast cancer phenotype in the Cypriot population.

Adult↗
PubMed2006

Germline CHEK2 mutations and colorectal cancer risk: different effects of a missense and truncating mutations?

Germline mutations in cell cycle checkpoint kinase 2 (CHEK2) have been associated with a range of cancer types, in particular of the breast and prostate. Protein-truncating mutations in CHEK2 have been reported to confer higher risks of cancer of the breast and the prostate than the missense I157T variant. In order to estimate the risks of colorectal cancer associated with truncating and missense CHEK2 mutations, we genotyped 1085 unselected colorectal cancer cases and 5496 controls for four CHEK2 founder mutations present in Poland. We observed an increased risk of colorectal cancer in association with the missense I157T mutation (odds ratios (OR) = 1.5; 95% CI 1.2-2.0; P = 0.002) but not with truncating mutations (OR = 1.0; 95% CI 0.5-1.8; P = 0.9); however the difference in the two OR was not statistically significant (P = 0.2). We conclude that the I157T mutation increases the risk of colorectal cancer in the population, but that truncating mutations may confer a lower risk or no increase in risk. It is important that other studies of CHEK2 mutation carriers be conducted to confirm this hypothesis.

Adult↗
PubMed2000

Allele diversity and germline mutation at the insulin minisatellite.

Previous analysis of germline mutation at highly unstable GC-rich minisatellites with continuous allele size distributions revealed similar meiotic recombinational mechanisms operating at all loci investigated. The insulin minisatellite has been studied intensively due to its associations with diabetes, polycystic ovary syndrome, obesity and birth size. Its bimodal allele size distribution in Caucasians suggests a much lower mutation rate and possible differences in the mutation process compared with highly unstable minisatellites. Mutation at the insulin minisatellite therefore was studied both indirectly from allele diversity surveys and directly by recovering de novo mutants from sperm DNA. Structural analysis of variant repeat distributions in 876 alleles identified 189 different alleles, almost all of which could be assigned to one of three very distinct lineages. Variation within a lineage was minor and due mainly to the gain or loss of one or a few repeat units. These events most probably arise by mitotic replication slippage at a frequency of perhaps 10(-3)per gamete. Sperm DNA analysis revealed a second class of mutation occurring at a frequency of approximately 2 x 10(-5)that involved highly complex intra- and inter-allelic rearrangements very similar to those seen at unstable minisatellites. These complex rearrangements were not seen in somatic DNA and are probably meiotic in origin. Minisatellite homozygosity did not reduce the frequency of these mutants in sperm. The insulin minisatellite therefore appears to evolve by two distinct processes: one involving slippage-like events and the second resulting in complex recombinational turnover of allele structure.

Alleles↗
PubMed1998

Novel germline mutations of hMSH2 in a patient with hereditary nonpolyposis colorectal cancer (HNPCC) and in a patient with six primary cancers.

We screened for germline mutations of mismatch repair genes, hMLH1 and hMSH2, in five Japanese families carrying hereditary nonpolyposis colorectal cancer (HNPCC) and in a patient with multiple primary cancers. Screening the entire coding regions of both genes using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis, we found two novel germline mutations in hMSH2. One was a 1-bp insertion in exon 12, detected in a patient who had undergone surgery six times for independent tumors (four primary colorectal carcinomas, a small intestinal carcinoma, and an endometrial cancer). The other, in a second patient, was a missense mutation from CTT to TTT at codon 390 in exon 7 that resulted in substitution of phenylalanine for leucine. This conservative alteration was not found in any of 50 normal controls, but we cannot exclude the possibility that it may represent a rare polymorphism rather than a factor in the disease.

Adult↗
PubMed2004

Immunoassay for wild-type protein in lymphocytes predicts germline mutations in patients at risk for hereditary colorectal cancer.

Using colorectal cancer (CRC) as an example, we present the hypothesis that quantitative immunoassays for wild-type (full-length) proteins can be used to identify carriers of traits for hereditary diseases. In the case of hereditary CRC, this involves identifying individuals with germline mutations in a mismatch-repair (MMR) gene (mainly hMSH2 or hMLH1) or in the adenomatous polyposis coli (APC) gene. Because expression of wild-type protein should reflect wild-type gene dosage, we predicted that individuals harboring a germline mutation will have a reduction of approximately 50% in expression in lymphocytes of the corresponding full-length protein. In this pilot study, we tested lymphoblastoid cell lines that had been established from controls and individuals with, or at high risk for, hereditary CRC: 9 lines from healthy, unaffected individuals; 4 from affected members in familial adenomatous polyposis families (with known germ-line APC mutation); 42 from CRC patients in our Familial CRC Registry (increased risk of hereditary nonpolyposis colon cancer as assessed by family history, age at adenoma or carcinoma diagnosis, and other clinical criteria). For MSH2 and MLH1 we used western blots; for APC we used immunoprecipitation. All familial adenomatous polyposis lines had about 50% less immunoprecipitable full-length APC protein. Some cell lines (7 of 42) from Familial CRC Registry patients showed on western blots a reduction (mean 46%) in either MSH2 or MLH1 (relative to the other protein). All 7 subsequently were proved to contain a germline MMR mutation. We conclude that (1) because most of the expected CRC-causing germ line mutations are truncation-causing, immunoassays for wild-type protein should be able to identify most individuals with hereditary CRC-causing traits; (2) these assays, which are more practical and inexpensive than current mutation-detecting tests for hereditary CRC traits, have the potential for commercial development into broad-based population screens of high-risk patients and their families and the potential to save both lives and health-care dollars; (3) this strategy may be useful for other hereditary cancers and even other hereditary diseases; (4) our approach has the potential to greatly benefit public-health programs for cancer control.

Adaptor Proteins, Signal Transducing↗
PubMed2002

Familial gastrointestinal stromal tumors associated with dysphagia and novel type germline mutation of KIT gene.

A family with multiple gastrointestinal stromal tumors (GISTs), a new type of germline mutation of KIT gene, and dysphagia is reported. The mutation was observed at Asp-820 in tyrosine kinase (TK) II domain. Mutations in TK II domain have been found in mast cell and germ cell tumors but not in GISTs, and the present family members are the first reported cases of GISTs with TK II domain mutations, including sporadic GISTs. Because interleukin 3-dependent Ba/F3 murine lymphoid cells transfected with the mutant KIT complementary DNA grew autonomously without any growth factors and formed tumors in nude mice, the mutation was considered to be gain-of-function type. Family members with the germline KIT mutation reported dysphagia, but those without the mutation did not. The mechanism of dysphagia was examined with gastrointestinal fiberscopy, endoscopic ultrasonography, and esophageal manometry. No mechanical obstruction was found, and the esophagus was not remarkably dilated. In the family members with dysphagia, endoscopic ultrasonography at the esophagocardiac junction showed a thickened hyperechoic layer between the circular and longitudinal muscle layers, suggesting hyperplasia of interstitial cells of Cajal at the myenteric plexus layer. Manometry showed low resting lower esophageal sphincter pressure and abnormal simultaneous contractions of the esophagus without normal peristalsis. These findings indicate that the dysphagia of the present family is different from typical achalasia. This is the first report of familial dysphagia caused by germline gain-of-function mutation of the KIT gene at the TK II domain.

Aged↗
PubMed2000

Multiple acral fibromas in a patient with familial retinoblastoma: a cutaneous marker of tumour-suppressor gene germline mutation?

We report a 40-year-old patient with familial retinoblastoma also affecting his elder son, who developed multiple fibromas on the periungual or subungual areas of all the fingers. Molecular analysis disclosed a loss of heterozygosity for the RB1 gene in the larger tumour, with disappearance of the normal allele and persistence of the mutated allele only. The similarity of this observation with distal fibrous tumours encountered in other diseases with germline mutations of tumour-suppressor genes such as neurofibromatosis type 1, tuberous sclerosis and multiple endocrine neoplasia type 1 led to the hypothesis that multiple acral benign tumours with a fibrous component might be a cutaneous marker of tumour suppressor gene germline mutation with low sensitivity but high specificity.

Adult↗
PubMed2005

BRCA2 germline mutation in a woman with uterine serous papillary carcinoma--case report.

BACKGROUND: Recently, a high incidence of BRCA1 cancer predisposing mutation was described among patients with Uterine Serous Papillary Carcinoma (USPC). A BRCA2 germline mutation in a USPC patient has never been reported. CASE: A 65-year-old Ashkenazi Jewish woman was diagnosed with USPC Stage III A. The patient family history included a mother with ovarian carcinoma, a maternal aunt who had breast carcinoma that was diagnosed at an early age, an additional maternal aunt who suffered from gastric carcinoma, and the patient's sister who had duodenal carcinoma. The patient was found to be a carrier of the germline BRCA2 cancer predisposing mutation (6174delT). CONCLUSIONS: We report the first case of a BRCA2 mutation in a USPC patient. A strong family history of breast and ovarian cancer with the presence of the BRCA2 germline mutation is an additional hint for the possible association between BRCA cancer predisposing mutations and USPC.

Aged↗
PubMed1994

Germline mutations of the p53 tumor suppressor gene in children with osteosarcoma.

PURPOSE: We investigated the possibility that a significant proportion of children with osteosarcoma harbor germline mutations of the p53 tumor suppressor gene and, therefore, this subgroup of pediatric cancer patients should be considered for large-scale predictive testing. PATIENTS AND METHODS: Genomic DNA extracted from peripheral-blood leukocytes from 235 unselected children with osteosarcoma from 33 institutions were screened for the presence of germline p53 mutations using constant denaturant gel electrophoresis (CDGE). Exons 5 through 8 were evaluated in all patients and exon 2 and exon 9 were analyzed in 59 and 95 patients, respectively. Those samples that showed aberrant migration on CDGE were sequenced or analyzed by restriction enzyme digestion of polymerase chain reaction (PCR) products to confirm the nature of the gene alteration. RESULTS: In 18 samples, CDGE showed fragments of the p53 gene with altered electrophoretic mobilities compared with wild-type p53. DNA sequencing showed that 11 samples had an identical, previously described polymorphism. The other seven contained heterozygous p53 mutations located in exon 5 (n = 3), exon 6 (n = 1), exon 7 (n = 1), and exon 8 (n = 2). Six alterations were missense mutations and one was a nonsense mutation. Three of these patients had first-degree relatives with cancer. One of these three kindreds had a family history consistent with Li-Fraumeni syndrome (LFS). CONCLUSION: We identified germline p53 mutations in seven of 235 (3.0%) children with osteosarcoma. Four of these mutations were found in patients who did not have first-degree relatives with cancer. Although genetic transmission of the altered p53 gene could not be tested in this survey because of how it was designed, it is possible that predictive testing for p53 mutations could identify unaffected relatives of gene carriers who also have a high risk for the development of cancer. This study provides evidence for the importance of considering children with osteosarcoma for predictive testing for germline p53 mutations.

Base Sequence↗