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.

SourceResearch connectionFrom yearThrough year

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

At least 325 records · Page 18Linked to original sources

PubMed1999

Germline mutations of p53 but not p16/CDKN2 or PTEN/MMAC1 tumor suppressor genes predispose to gliomas. The ANOCEF Group. Association des NeuroOncologues d'Expression Française.

Constitutional DNA from 44 selected patients suspected of being genetically predisposed to develop astrocytic tumors was analyzed for germline mutations of the p53, p16, and PTEN genes. Six constitutional missense mutations of the p53 gene were identified (13.6%), but no mutations of the p16 and PTEN genes were found, suggesting that (1) germline p53 mutations contribute to a small portion of astrocytic tumors, (2) inherited mutations of the p16 and PTEN gene do not predispose to the development of gliomas, and (3) other genes are involved in glioma predisposition.

Amino Acid Substitution↗

PubMed2002

Association between c135G/A genotype and RET proto-oncogene germline mutations and phenotype of Hirschsprung's disease.

BACKGROUND: Several genes, including the major susceptibility gene RET, have roles in development of Hirschsprung's disease. Results of genetic-linkage analysis of patients with familial disease with both long-segment and short-segment phenotypes have shown close linkage with the RET locus. We aimed to investigate whether both RET mutations and polymorphisms contribute to phenotype of Hirschsprung's disease. METHODS: We looked at the coding region of all 21 exons of the RET proto-oncogene, including the flanking intronic sequences, by direct DNA sequencing in 76 caucasians from Germany with Hirschsprung's disease. FINDINGS: 20 different mutations were detected in 18 patients. Mutations were under-represented in patients with a homozygous RET c135A/A genotype in association with short-segment phenotype. Short-segment phenotype also arose if the RET mutation was on the c135A allele; conversely, a RET germline mutation on the c135G allele resulted in long-segment phenotype, particularly in heterozygous c135G/A patients. INTERPRETATION: These observations lend support to the idea that both RET alleles have a role in pathogenesis of Hirschsprung's disease, in a dose-dependent fashion. We also showed that the c135G/A polymorphism modifies the phenotype by a within-gene interaction between the c135A variant and a mutation.

Alleles↗

PubMed1994

Cooperative tumorigenic effects of germline mutations in Rb and p53.

The tumour suppressor genes Rb and p53 are mutated in several types of human cancer, and many tumour types carry mutations in both genes. To study how these genes normally function, we and others have created mouse strains with Rb and p53 mutations. Here we describe the phenotypic effects of combined germline mutations in these two tumour suppressor genes. Mice mutant for both genes have reduced viability and exhibit novel pathology including pinealoblastomas, islet cell tumours, bronchial epithelial hyperplasia and retinal dysplasia. These data indicate that mutations in Rb and p53 can cooperate in the transformation of certain cell types in the mouse.

Adenoma, Islet Cell↗

PubMed2002

Germline mutation of ARF in a melanoma kindred.

Familial melanoma predisposition is associated with germline mutations at the CDKN2A/ARF locus in up to 40% of families. The exact role of the two proteins encoded by this complex locus in this predisposition is unclear. Most mutations affect either CDKN2A only or products of both genes. Recently a deletion affecting ARF-specific exon 1beta was reported in a family with melanoma and neural tumours. However, the possibility of this deletion also altering the CDKN2A transcript could not be excluded. More convincingly, a 16 base pair insertion in exon 1beta has been reported in an individual with multiple melanomas suggesting a direct role for ARF in melanoma predisposition. We report here a splice mutation in exon 1beta in a family with melanoma that results in ARF haploinsufficiency. The mutation was observed in a mother and daughter with melanoma. A sibling of the mother with breast cancer also had this mutation. Analysis of the melanoma from one individual revealed a 62 bp deletion in exon 3 of the wildtype allele and loss of the mutant allele; these somatic changes would affect both CDKN2A and ARF. These somatic events suggest that concomitant inactivation of both ARF and CDKN2A may be necessary for melanoma development and that mutations in ARF and CDKN2A possibly confer different levels of susceptibility to melanoma, with the former associated with lesser predisposition. In this situation, the events follow a 'three-hit' model as observed in tumours from FAP patients with an attenuated phenotype. Overall, the data suggest a direct role for ARF haploinsufficiency in melanoma predisposition and co-operation between ARF and CDKN2A in tumour formation, consistent with recent observations in Cdkn2a-specific knockout mice.

Adult↗

PubMed1999

Normal thyroid pathology in patients undergoing thyroidectomy for finding a RETgene germline mutation: a report of three cases and review of the literature.

Genetic screening for germline RET proto-oncogene mutation in hereditary medullary thyroid cancer (MTC) is accurate and allows for preventive total thyroidectomy to be performed early in patients who are gene carriers. We report 3 children who underwent preventive total thyroidectomy based on the finding of a RETgene germline mutation, but who had no evidence of MTC or C-cell hyperplasia on permanent histology, even after calcitonin immunostaining. Review of the English literature of patients undergoing preventive thyroidectomy for a positive RETgene germline mutation, shows that 3.4% of these patients (a total of 209 patients) had normal thyroid glands. Also, 8.6% of patients undergoing preventive total thyroidectomy with prophylactic central neck node dissection had cervical node metastases. We conclude that preventive thyroidectomy in patients screened early for germline RETgene mutation allows for earlier diagnosis and treatment of patients, sometimes even before any hyperplasia or neoplasia can be demonstrated because cervical node metastases can occur early and be demonstrated even with small tumors (< 1 cm), we recommend prophylactic central neck node dissection at the time of preventive thyroidectomy.

Adolescent↗

PubMed2004

Novel germline mutations in the BRCA1 and BRCA2 genes in Indian breast and breast-ovarian cancer families.

The two major hereditary breast/ovarian cancer predisposition tumor suppressor genes, BRCA1 and BRCA2 that perform apparently generic cellular functions nonetheless cause tissue-specific syndromes in the human population when they are altered, or mutated in the germline. However, little is known about the contribution of BRCA1 and BRCA2 mutations to breast and/or ovarian cancers in the Indian population. We have screened for mutations the entire BRCA1 and BRCA2 coding sequences, and intron-exon boundaries, as well as their flanking intronic regions in sixteen breast or breast and ovarian cancer families of Indian origin. We have also analyzed 20 female patients with sporadic breast cancer regardless of age and family history, and 69 unrelated normal individuals as control. Thus a total of 154 samples were screened for BRCA1 and BRCA2 mutations using a combination of polymerase chain reaction-mediated site directed mutagenesis (PSM), polymerase chain reaction-single stranded conformation polymorphism assay (PCR-SSCP) and direct DNA sequencing of PCR products (DS). Twenty-one sequence variants including fifteen point mutations were identified. Five deleterious pathogenic, protein truncating frameshift and non-sense mutations were detected in exon 2 (c.187_188delAG); and exon 11 (c.3672G>T) [p.Glu1185X] of BRCA1 and in exon 11 (c.5227dupT, c.5242dupT, c.6180dupA) of BRCA2 (putative mutations - four novel) as well as fourteen amino acid substitutions were identified. Twelve BRCA1 and BRCA2 missense variants were identified as unique and novel. In the cohort of 20 sporadic female patients no mutations were found.

Adult↗

PubMed2002

p53 Germline mutation in a patient with Li-Fraumeni Syndrome and three metachronous malignancies.

PURPOSE: Germline mutations of the p53 coding region are present in approximately 50-70% of patients with Li-Fraumeni Syndrome (LFS), a rare hereditary disorder of familial and intraindividual clustering of different malignancies such as sarcoma (index tumor), breast cancer, brain tumors, leukemias, and adrenocortical carcinomas, the latter usually in young children. Both onset and spectrum of malignancies in individuals with LFS are thus heterogenous and may, less frequently, also include other epithelial and mesenchymal tumors. A 32-year-old female presented for genetic counseling with a history of leiomyosarcoma at age 22, malignant melanoma (a rare component of LFS) at age 26, and breast cancer at age 30. All three tumors had been treated surgically. Astrocytoma and breast cancer, respectively, had been diagnosed in her brother and mother before age 30. Other malignancies diagnosed early in life in relatives of the mother were: prostate cancer, stomach cancer, and carcinoma of the larynx. METHODS: Upon written informed consent, DNA was extracted from peripheral blood mononuclear cells of the proband, and p53 exons 4-8 analyzed for mutations by SSCP and DNA sequencing. RESULTS: A G:C to A:T mutation at codon 175 of p53 resulting in an arginine --> histidine substitution was detected, confirming the clinical diagnosis of LFS. CONCLUSIONS: The patient and her family are being followed further, but testing of her children for the presence of this mutation is currently being withheld. The difficulties in the management and treatment of patients with this clinically heterogenous disorder are discussed.

Adult↗

PubMed2002

High prevalence of the G101W germline mutation in the CDKN2A (P16(ink4a)) gene in 62 Italian malignant melanoma families.

CDKN2A germline mutation frequency estimates are commonly based on families with several melanoma cases. When we started counseling in a research setting on gene susceptibility analysis in northern and central Italy, however, we mostly found small families with few cases. Here we briefly characterize those kindred, estimate CDKN2A/CDK4 mutation test yields, and provide indications on the possibility of implementing formal DNA testing for melanoma-prone families in Italy. In September 1995 we started genetic counseling in a research setting at our Medical Genetics Center. Screening for CDKN2A/CDK4 mutations was performed on families with two melanoma patients, one of whom was younger than 50 years at onset, the other complying with one of the following: 1) being a first-degree relative, 2) having an additional relative with pancreatic cancer, or 3) having multiple primary melanomas. Sixty-two of 67 (80%) melanoma cases met our criteria. Four previously described CDKN2A mutations (G101W, R24P, V126D, and N71S) were found in 21 of the 62 families (34%) with a high prevalence of G101W (18/21). The percentage of families with two melanoma cases/family harboring a mutation was low (7%, 2/27), but rose to 45% (9/20) if one of the melanoma patients carried multiple melanomas or if pancreatic cancer was present in that family. In the 15 families with three melanoma cases the presence of a mutation was higher (67%, 10/15) and reached 100% in the 4 families with four or more melanoma cases. Our results suggest that CDKN2A/CDK4 counseling-based mutational analysis may be reasonably efficient also for families with two melanoma cases, if one patient carries multiple melanomas or if pancreatic cancer is present in the family.

Adolescent↗

PubMed1999

Germline mutation and genome instability.

Colorectal tumorigenesis has been associated with the progressive acquisition of a variety of genomic alterations in neoplastic cells. In 5-10% of cases, a strong family history of cancer suggests a major predisposition, either familial adenomatous polyposis (FAP) or HNPCC syndrome. In 1987, the gene responsible for FAP was localized on chromosome 5q. In 1991, the International Collaborative Group on HNPCC set stringent criteria for the diagnosis of HNPCC, to homogenize families that should be entered in large linkage analyses. In the past five years, five MMR genes could be identified as the site of germline mutations associated with a HNPCC syndrome (MSH2, MLH1, PMS1, PMS2, and MSH6). The TGFbeta RII gene has been found mutated at the germline level in a small number of HNPCC patients. The DNA mismatch repair pathway is essential for the correct maintenance of genetic information. The slippage occurs usually at microsatellite loci and the defect of one MMR gene leads to the accumulation of replication errors in such deficient cells. The tumours that exhibit the highest frequency of RER at microsatellite loci, thus termed RER+, account for 10-15% of all colorectal cancers, and for 92% of those developed in a context of a HNPCC syndrome.

Animals↗

PubMed2003

Contribution of germline mutations in BRCA2, P16(INK4A), P14(ARF) and P15 to uveal melanoma.

PURPOSE: Reports suggest that a subset of uveal melanoma is familial. The association of uveal melanoma with breast and ovarian cancer and the increased risk in BRCA2-linked families implicates germline BRCA2 mutations as the cause of a subset of uveal melanomas. Similarly, the association between cutaneous and uveal melanomas in some families, coupled with the high frequency of somatic deletions of the INK4A-ARF locus in uveal melanomas, strongly suggests that mutations in P16(INK4A) and P15 account for a proportion of uveal melanomas. METHODS: To examine this proposition, a systematically ascertained series of 385 patients with uveal melanoma were screened for germline mutations in BRCA2, P16(INK4A), P14(ARF), and P15. RESULTS: One patient was found to harbor a Gly35Ala substitution in exon 1alpha of P16(INK4A), which has previously been reported to be pathogenic. No mutations were detected in P14(ARF) or P15. None of the patients harbored germline nucleotide changes that lead to truncation or that create or disrupt consensus splice sites of BRCA2 or missense variants with clear pathogenic potential. CONCLUSIONS: These findings suggest that less than 2% of cases of uveal melanoma can be ascribed to germline mutations in BRCA2, P16(INK4A), P14(ARF), or P15. It is likely that mutations in other genes contribute to an inherited predisposition to uveal melanoma.

Adult↗

PubMed2007

Deactivating germline mutations in LEMD3 cause osteopoikilosis and Buschke-Ollendorff syndrome, but not sporadic melorheostosis.

UNLABELLED: Autosomal dominant OPK and BOS feature widespread foci of osteosclerotic trabeculae without or with skin lesions, respectively. Occasionally, a larger area of dense bone in OPK or BOS resembles MEL, a sporadic sclerosing disorder primarily involving cortical bone. Others, finding deactivating germline LEMD3 mutations in OPK or BOS, concluded such defects explain all three conditions. We found germline LEMD3 mutations in OPK and BOS but not in sporadic MEL. INTRODUCTION: In 2004, others discovered that heterozygous, loss-of-function, germline mutations in the LEMD3 gene (LEMD3 or MAN1) cause both osteopoikilosis (OPK) and Buschke-Ollendorff syndrome (BOS). OPK is an autosomal dominant, usually benign, skeletal dysplasia featuring multiple, small, especially metaphyseal, oval or round, dense trabecular foci distributed symmetrically throughout the skeleton. BOS combines OPK with connective tissue nevi comprised of collagen and elastin. In some OPK and BOS families, an individual may have relatively large, asymmetric areas of dense cortical bone interpreted as melorheostosis (MEL). MEL, however, classically refers to a sporadic, troublesome skeletal dysostosis featuring large, asymmetric, "flowing hyperostosis" of long bone cortices often with overlying, constricting soft tissue abnormalities. However, a heterozygous germline mutation in LEMD3 was offered to explain MEL. MATERIALS AND METHODS: We studied 11 unrelated individuals with sclerosing bone disorders where LEMD3 mutation was a potential etiology: familial OPK (1), familial BOS (2), previously reported familial OPK with MEL (1), sporadic MEL (3), sporadic MEL with mixed-sclerosing-bone dystrophy (1), and patients with other unusual sclerosing bone disorders (3). All coding exons and adjacent mRNA splice sites for LEMD3 were amplified by PCR and sequenced using genomic DNA from leukocytes. We did not study lesional tissue from bone or skin. RESULTS: In the OPK family, a heterozygous nonsense mutation (c.1433T>A, p.L478X) was discovered in exon 1. In the two BOS families, a heterozygous nonsense mutation (exon 1, c.1323C>A, p.Y441X) and a heterozygous frame-shift mutation (exon 1, c.332_333insTC) were identified. In the individual with MEL and familial OPK, a heterozygous nonsense mutation (c.1963C>T, p.R655X) was detected in exon 7. However, no LEMD3 mutation was found for any other patient, including all four with sporadic MEL. CONCLUSIONS: We confirm that OPK and BOS individuals, including those with MEL-like lesions, have heterozygous, deactivating, germline LEMD3 mutations. However, MEL remains of unknown etiology.

Child↗

PubMed2006

MSH6 germline mutations in early-onset colorectal cancer patients without family history of the disease.

Germline MLH1 and MSH2 mutations are scarce in young colorectal cancer patients with negative family history of the disease. To evaluate the contribution of germline MSH6 mutations to early-onset colorectal cancer, we have analysed peripheral blood of 38 patients diagnosed with this disease before 45 years of age and who presented no family history of hereditary nonpolyposis colorectal cancer-related cancers. Blood samples from 108 healthy volunteers were analysed for those genetic alterations suspected to affect the function of MSH6. Of the seven (18.4%) MSH6 alterations found, we have identified three novel germline mutations, one 8 bp deletion leading to a truncated protein and two missense mutations resulting in the substitution of amino acids belonging to different polarity groups. High-frequency microsatellite instability was found in the patient with the MSH6 deletion, but not in the other 27 carcinomas analysed. No MLH1 promoter methylation was detected in tumour tissue. Our findings suggest that germline MSH6 mutations contribute to a subset of early-onset colorectal cancer. Further studies are warranted to understand the genetic and environmental factors responsible for the variable penetration of MSH6 germline mutations, as well as to identify other causes of early-onset colorectal cancer.

Adolescent↗

PubMed1995

Identification of RB1 germline mutations in Argentinian families with sporadic bilateral retinoblastoma.

Hereditary predisposition to retinoblastoma is caused by germline mutations in the RB1 gene. Most of these mutations occur de novo and differ from one patient to another. DNA samples from 10 families with a child presenting sporadic bilateral retinoblastoma have been analysed for the causative mutation. Using intragenic DNA polymorphisms we detected large deletions in two patients. Heteroduplex and DNA sequence analysis of PCR products from each exon and the promoter region showed small mutations in four patients: a C to T transition in exon 18; 1 bp and 2 bp deletion in exons 20 and 19 respectively; and a 4 bp insertion in exon 7. All these mutations are likely to result in premature termination of transcription. In one of these families, an unaffected carrier was detected. This emphasises the importance of detection of the causative mutation for predictive diagnosis in families with sporadic bilateral retinoblastoma.

Argentina↗

PubMed1998

A heterozygous germline mutation of the PTEN/MMAC1 gene in a patient with Cowden disease.

Cowden disease, or multiple hamartoma syndrome, is an autosomal dominant inherited cancer syndrome with a high risk of thyroid and breast cancers. Its susceptibility gene has been mapped to chromosome 10q22-23. Because a newly found tumor suppressor gene, PTEN/MMAC1, often mutated in glioblastoma and in prostatic and breast cancers, has been mapped to the same chromosomal locus, it is suspected that it may be the gene responsible for Cowden disease. germline mutations of the gene have been reported in 4 of 5 families with Cowden disease. We performed a genetic analysis of the PTEN/MMAC1 gene in a sporadically found patient with the disease who had no apparent family history of the disease. We found a germline heterozygous mutation of the PTEN/MMAC1 gene in a patient with Cowden disease. The mutation, a C to T substitution of a single base at codon 130, leads to a formation of stop codon, generating a truncated protein lacking both protein phosphatase signature motif and tensin-like domain. Our finding supports the hypothesis of the PTEN/MMAC1 gene as being responsible for Cowden disease even in a sporadic case.

Adult↗

PubMed2003

Germline mutations in fumarate hydratase (FH) do not predispose to prostate cancer.

Inherited susceptibility to prostate cancer has been linked to a number of chromosomal regions, however no genes have been unequivocally shown to underlie reported linkages. The putative gene localised to chromosome 1q42-q43, has been designated PCaP. We have recently shown that germline mutations in the fumarate hydratase (FH) gene located on 1q43 cause smooth muscle tumours and renal cell carcinoma. It is conceivable that germline FH mutations might confer an increased risk of prostate cancer and underlie linkage of prostate cancer to PCaP. To examine this proposition we have analysed the entire coding region of FH in 160 prostate cancer cases in 77 multiple case families. No pathogenic mutations in FH were identified in any of the cases. This data makes it highly unlikely that mutations in FH confer susceptibility to prostate cancer.

Aged↗

PubMed1993

Germline mutations of the p53 tumor-suppressor gene in cancer-prone families: a review.

Li-Fraumeni syndrome (LFS) is an autosomal dominant disorder that predisposes individuals to multiple forms of cancer including breast carcinoma, soft tissue sarcoma, osteosarcoma, leukemia and adrenocortical carcinoma. These diverse tumor types develop at unusually early ages. Analysis of the tumor suppressor gene p53 in family members with LFS have demonstrated that germline mutations in the p53 gene were present in most of the LFS family tested so far. Furthermore, germline p53 mutations were also found in cancer-prone individuals which were not indicative of the LFS.

Genes, p53↗

PubMed2003

Novel germline mutation of the PTEN gene in a Japanese family with Cowden disease.

We report a novel germline mutation of the PTEN gene in a Japanese family with Cowden disease. A 46-year-old Japanese man and his mother were diagnosed as having Cowden disease. Their physical examinations revealed multiple facial trichilemmoma, oral mucosal papillomatosis, palmoplantar keratosis, and gastrointestinal polyposis. The single-strand conformation polymorphism (SSCP) analysis showed an abnormal band on exon 7 of their PTEN gene. Direct sequence analysis of exon 7 detected a TAAA insertion to codon 221, producing a stop codon (c.663ins TAAA).

Adult↗

PubMed2004

Six novel heterozygous MLH1, MSH2, and MSH6 and one homozygous MLH1 germline mutations in hereditary nonpolyposis colorectal cancer.

Most hereditary nonpolyposis colorectal cancer (HNPCC) cases are caused by germline mutations of mismatch repair (MMR) genes (i.e., MLH1, MSH2, or MSH6). Here we describe six novel mutations in patients referred for genetic assessment. All of these mutations lead to premature translation termination. Five single base pair deletions lead to frameshift (MLH1: g.38-39insCCCA, g.1971del.T; MSH2: g.163del.C, g.746del.A; MSH6: g.3320del.A) and one nonsense mutation in MSH2 g.1030C>T leads to a stop codon: p.Q344X. In one patient, the previously described MLH1 nonsense mutation g.806C>G was found in a homozygous state. In this patient, the familial histories of both the mother and father suggested HNPCC syndrome. This patient developed colon cancer at 22 years of age, suggesting a more aggressive phenotype. The results of our study provide further insight into the mutational spectrum of MMR genes in HNPCC families.

Adaptor Proteins, Signal Transducing↗