Biomedical subjects

Marion Gauthier-Villars

Publications and source records attributed to Marion Gauthier-Villars.

13 recordsLinked to original sources

PubMed2025

A functional assay to classify RB1 variants of uncertain significance.

PURPOSE: The RB1 gene encodes the retinoblastoma protein (pRB) playing a major role in cell cycle control, particularly by its interaction with E2F transcription factors. Familial forms of retinoblastoma are caused by germline pathogenic variants in the RB1 gene predisposing to retinoblastoma and other tumors. By analyzing the RB1 gene in patients with retinoblastoma, we found that missense variants often remain variants of uncertain significance (VUS). METHODS: To classify RB1 VUS, we developed a functional assay evaluating their impact on the ability of pRB to inhibit the activity of the E2F1 promoter, with a luciferase reporter gene. A set of 14 pathogenic/likely pathogenic and benign/likely benign RB1 variants was used for validation. RESULTS: We tested 16 VUS detected in patients with retinoblastoma and found that 9 VUS reduced the ability of pRB to inhibit E2F1 promoter. Among them, the (RB1) c.2263T>G p.(Phe755Val) variant showed a reduced level of pRB on Western blot, suggesting a defect in pRB stability. By applying the criterion PS3_moderate of the American College of Medical Genetics and Genomics/Association for Molecular Pathology classification to this functional assay, 5 of the 9 VUS with functional impact could be classified as likely pathogenic. CONCLUSION: This functional assay can improve the molecular diagnosis of retinoblastoma predisposition by a better determination of pathogenic/likely pathogenic RB1 variants.

Humans↗

PubMed2025

Uveal Melanoma and the Lynch Syndrome Tumor Spectrum.

IMPORTANCE: To date, no environmental factors and few therapeutic options are known for uveal melanoma (UM), the most common malignant intraocular primary tumor in adults. Identification of new predisposition factors could lead to better monitoring and possibly improved treatments of patients with UM. OBJECTIVE: To identify new genetic alterations predisposing for UM. DESIGN, SETTING, AND PARTICIPANTS: This was a prospective cohort study conducted at Institut Curie in Paris, France, among 381 consecutive patients diagnosed with UM between July 2021 and February 2023. UM was diagnosed clinically by ophthalmologists, and a senior pathologist confirmed the diagnosis when tumor or biopsy was available. All participants received genetic counseling and consented to extended genetic testing. A panel of 122 genes predisposing to cancer were analyzed by targeted sequencing on germline DNA from these patients. MAIN OUTCOMES AND MEASURES: Frequency of pathogenic variants (PVs) in genes from a targeted panel, with classification of germline PVs done according to the American College of Medical Genetics and Genomics guidelines and the French Unicancer Genetics Group. RESULTS: A total of 79 PVs were identified in 70 participants (41 female and 29 male; mean [SD] age, 60.6 [15.3] years). Among them, 21 were found in clinically relevant genes, with an enrichment in the mismatch repair (MMR) genes, involved in Lynch syndrome, a frequent predisposition to colon and endometrial cancers. This finding suggested MMR germline PVs could also predispose to UM. One tumor was available from a participant carrying a MLH1 germline PV. The tumor exhibited a monosomy 3 with loss of the wild-type allele of MLH1, located on chromosome 3. Loss of expression of MLH1 was observed by immunohistochemistry, and MMR variant signatures SBS6, ID1, and ID2 were identified from the whole-genome sequencing of this tumor, supporting the possibility that MLH1 contributes to the oncogenesis of this UM. CONCLUSIONS AND RELEVANCE: This prospective germline study on patients with UM provided evidence supporting the notion that MMR germline alterations are enriched among patients with UM and may contribute to oncogenesis of UM, and that UM may therefore be a rare tumor manifestation of Lynch syndrome.

Humans↗

PubMed2007

Genotype-phenotype correlations in hereditary familial retinoblastoma.

We studied 50 unrelated pedigrees with a family history of retinoblastoma (Rb) (165 carriers of a RB1 mutation) to delineate the spectrum of RB1 germline mutations in familial Rb and to identify genotype-phenotype correlations as well as putative modifiers. Patients were followed at Institut Curie and they were examined by an ophthalmologist, a pediatrician, and a geneticist. All cases of familial Rb were determined via genetic counseling. Clinical features included disease status, laterality, age at diagnosis, mutation type, follow-up, and disease-eye ratio (DER). To eliminate mosaic cases, first-generation carriers displaying low-penetrance (LP) Rb were excluded from the analysis. Complete penetrance was the rule for nonsense and frameshift mutations (25 families) and high penetrance was observed for large rearrangements (eight families). Promoter (two families) and missense (two families) mutations displayed heterogeneous phenotypes and LP. Variable penetrance was observed for splice abnormalities (13 families) and was explained by in/out of frame mutations or respect of functional domains. Surprisingly, two families with the LP g.45867G>T/IVS6+1G>T mutation presented data that conflicted with the data reported in previous publications, as unaffected carriers had paternally inherited mutant alleles. Moreover, RNA analyses suggested that the lack of penetrance in unaffected carriers could be explained by an increase in expression levels of the wild-type allele. This observation prompted us to define a new class "3" of LP alleles. We believe this is the first large-scale study of familial Rb with a high level of homogeneity in the clinical and genetic analysis of patients and their relatives, thereby allowing for reliable intrafamilial genotype-phenotype correlations. Our analysis suggests in some cases the influence of modifier factors probably involved in mRNA level regulation and/or pRB pathway regulation.

Child, Preschool↗

PubMed2006

Retinoblastoma.

Retinoblastoma is a rare eye tumor of childhood that arises in the retina. It is the most common intraocular malignancy of infancy and childhood; with an incidence of 1/15,000-20,000 live births. The two most frequent symptoms revealing retinoblastoma are leukocoria and strabismus. Iris rubeosis, hypopyon, hyphema, buphthalmia, orbital cellulites and exophthalmia may also be observed. Sixty per cent of retinoblastomas are unilateral and most of these forms are not hereditary (median age at diagnosis two years). Retinoblastoma is bilateral in 40% of cases (median age at diagnosis one year). All bilateral and multifocal unilateral forms are hereditary. Hereditary retinoblastoma constitutes a cancer predisposition syndrome: a subject constitutionally carrying an RB1 gene mutation has a greater than 90% risk of developing retinoblastoma but is also at increased risk of developing other types of cancers. Diagnosis is made by fundoscopy. Ultrasound, magnetic resonance imaging (MRI) and computed tomography (CT) scans may contribute to diagnosis. Management of patients with retinoblastoma must take into account the various aspects of the disease: the visual risk, the possibly hereditary nature of the disease, the life-threatening risk. Enucleation is still often necessary in unilateral disease; the decision for adjuvant treatment is taken according to the histological risk factors. Conservative treatment for at least one eye is possible in most of the bilateral cases. It includes laser alone or combined with chemotherapy, cryotherapy and brachytherapy. The indication for external beam radiotherapy should be restricted to large ocular tumors and diffuse vitreous seeding because of the risk of late effects, including secondary sarcoma. Vital prognosis, related to retinoblastoma alone, is now excellent in patients with unilateral or bilateral forms of retinoblastoma. Long term follow-up and early counseling regarding the risk of second primary tumors and transmission should be offered to retinoblastoma patients.

Child, Preschool↗

PubMed2006

Patients' characteristics and rate of Internet use to obtain cancer information.

The aim of this study was to present baseline data on the access to Internet by French breast cancer patients attending genetic clinics and to examine factors affecting Internet health-related use. Twenty-four percent of participants used Internet to obtain information about the disease. This rate was higher among patients with health occupations [adjusted odds ratio (adjOR) 2.6; 95% confidence interval (CI) 1.3-5.1], the most highly educated (adjOR 2.1; 95% CI 1.1-4.0) and those under 41 years of age (adjOR 7.3; 95% CI 2.1-26.2). Almost one of every three women was dissatisfied of this source of information.

Adult↗

PubMed2006

Pregnancies, breast-feeding, and breast cancer risk in the International BRCA1/2 Carrier Cohort Study (IBCCS).

BACKGROUND: Multiparity, young age at first childbirth, and breast-feeding are associated with a reduced risk of breast cancer in the general population. The breast cancer predisposition gene, BRCA1, regulates normal cell differentiation. Because mammary gland cells divide and differentiate during pregnancy, reproductive factors may influence breast cancer risk in BRCA1/2 mutation carriers differently than they do in noncarriers. METHODS: We performed a retrospective cohort study of 1601 women in the International BRCA1/2 Carrier Cohort Study cohort, all of whom carried a mutation in BRCA1 or BRCA2. Information on reproductive factors was obtained from a questionnaire. At the time of interview 853 subjects were classified with breast cancer. Data were analyzed by using a weighted cohort approach. All statistical tests were two-sided. RESULTS: There was no statistically significant difference in the risk of breast cancer between parous and nulliparous women. Among parous women, an increasing number of full-term pregnancies was associated with a statistically significant decrease in the risk of breast cancer (Ptrend = .008); risk was reduced by 14% (95% confidence interval [CI] = 6% to 22%) for each additional birth. This association was the same for carriers of mutations in either BRCA1 or BRCA2 and was restricted to women older than 40 years. In BRCA2 mutation carriers, first childbirth at later ages was associated with an increased risk of breast cancer compared with first childbirth before age 20 years (20-24 years, hazard ratio [HR] = 2.33 [95% CI = 0.93 to 5.83]; 25-29 years, HR = 2.68 [95% CI = 1.02 to 7.07]; > or = 30 years, HR = 1.97 [95% CI = 0.67 to 5.81]), whereas in BRCA1 mutation carriers, first childbirth at age 30 years or later was associated with a reduced risk of breast cancer compared with first childbirth before age 20 years (HR = 0.58 [95% CI = 0.36 to 0.94]). Neither history of interrupted pregnancies (induced abortions or miscarriage) nor history of breast-feeding was statistically significantly associated with the risk of breast cancer. CONCLUSIONS: BRCA1 and BRCA2 mutation carriers older than 40 years show a similar reduction in breast cancer risk with increasing parity as non-carriers.

Abortion, Induced↗

PubMed2006

Impact of an information booklet on satisfaction and decision-making about BRCA genetic testing.

The aim of this study was to assess the impact of a standardized patient information booklet on decisions women make about genetic testing. This French national multi-centre survey included all women with cancer to whom genetic testing for BRCA1/2 mutation had been proposed. The control group was surveyed before the booklet became available (n = 263), and the experimental group, after being given it personally (n = 297). After multivariate adjustment, the booklet had a positive impact on satisfaction with the information provided (Odds ratio (OR) = 2.9; 99% confidence interval (CI) = 1.7-5.0; P = 0.001), decreased the decisional conflicts due to lack of information (OR = 1.9; 99% CI = 1.1-3.3; P = 0.002), and had a marginal impact on knowledge (R2-gain = 3%; P = 0.001). The women in the experimental group decided more frequently to undergo testing (99% vs. 95%; P = 0.009). In addition to a consultation providing more tailored information, a standardized written document improved the decision-making process involved in giving informed consent to genetic testing.

Breast Neoplasms↗

PubMed2005

Cholestasis in children with portal vein obstruction.

We describe cholestasis as a result of bile duct abnormalities in 8 children with portal vein obstruction. In a clinical, biochemical and radiological investigation of 121 children with cavernous transformation of the portal vein seen between 1986 and 2000, 8 presented with jaundice, pruritus, and/or raised serum aminotransferases and/or gamma glutamyl transpeptidase (gamma GT) activities. Each displayed dilation and narrowing of intra- and/or extrahepatic bile ducts. Surgical decompression of the portal system (portal-systemic or Rex anastomosis) resulted in the regression of the signs of cholestasis in all children. We conclude that children with portal vein obstruction may exhibit clinically significant cholestasis as a result of external compression of the bile duct by the cavernoma.

Child↗

PubMed2004

[Genetic predisposition and ovarian cancer].

The genetic predisposition to epithelial ovarian cancer can be distinguished in two different forms: familial breast and/or ovarian cancer; familial colon, endometrium, ovarian cancer or HNPCC syndrome (hereditary non polyposis colorectal cancer). The BRCA1 and BRCA2 genes are involved in familial breast and (or) ovarian cancer. Mutations of these two genes could explain 5.5% (2-7%) of ovarian cancers. The hMLH1, hMSH2, and hMSH6 genes are involved in the HNPCC syndrome. The mutations of these genes could explain 1% to 2% of ovarian cancers. The clinical management of women at ovarian cancer risk is variable and dependent on the predisposition going from regular examination until prophylactic oophorectomy in the presence of BRCA mutations.

Breast Neoplasms↗

PubMed2003

Characterisation of a 161 kb deletion extending from the NBR1 to the BRCA1 genes in a French breast-ovarian cancer family.

A large germline deletion removing exons 1 to 22 of the BRCA1 gene has been previously detected using quantitative PCR based methods (QMPSF and real time PCR gene dosage assay) in a woman affected with breast and ovarian cancer. Here, we report its characterisation by using colour bar code on combed DNA of the BRCA1 region. The 5' boundary is located in a Alu Y sequence in NBR1 intron 18 whereas the 3' boundary is located in a Alu Sc sequence in BRCA1 intron 22. This 161 kb deletion encompassing the NBR1, PsiBRCA1, NBR2 and BRCA1 genes is the largest BRCA1 deletion reported so far. No specific phenotype was associated with the hemizygosity of these four genes.

BRCA1 Protein↗

PubMed2003

Familial uveal melanoma: a report on two families and a review of the literature.

PURPOSE: A total of 69 families affected by uveal melanoma have been reported in the literature. This report describes two additional families. In addition to presenting these cases, which constitute exceptions, the paper reviews the literature. MATERIAL AND METHODS: Two families, each with two affected members, were analysed in this retrospective study. The pedigree of each family has been pieced together. RESULTS: Considering the low incidence of familial uveal melanoma in the general population, it seems unlikely that inherited genetic factors are responsible for the condition; this question remains difficult to resolve. DISCUSSION: The characteristics of each family history are described and compared with the literature data. The mode of possible inheritance is discussed. Both the histopathology and anatomical location are studied, after which we discuss the body of evidence to establish whether there is an inherited cancer predisposition syndrome in patients with familial uveal melanoma. CONCLUSION: The statistical likelihood of such an uncommon tumour occurring independently in two or more family members leads us to believe that some cases of familial uveal melanoma may go unrecognized, and that reports on too few families have been published worldwide to prove the existence of a single mendelien gene. However, appropriate tissue samples, such as blood and tumour samples, should be obtained and conserved for present or future cytogenetic and molecular genetic studies.

Adult↗

PubMed2002

Oral contraceptives and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers.

BACKGROUND: Oral contraceptive use has been associated with an increase in the risk of breast cancer in young women. We examined whether this association is seen in women at high risk of breast cancer because they carry a mutation in one of two breast cancer susceptibility genes, BRCA1 and BRCA2. METHODS: We performed a matched case-control study on 1311 pairs of women with known deleterious BRCA1 and/or BRCA2 mutations recruited from 52 centers in 11 countries. Women who had been diagnosed with breast cancer were matched to control subjects by year of birth, country of residence, mutation (BRCA1 or BRCA2), and history of ovarian cancer. All study subjects completed a questionnaire about oral contraceptive use. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived by conditional logistic regression. All statistical tests were two-sided. RESULTS: Among BRCA2 mutation carriers, ever use of oral contraceptives was not associated with an increased risk of breast cancer (OR = 0.94, 95% CI = 0.72 to 1.24). For BRCA1 mutation carriers, ever use of oral contraceptives was associated with a modestly increased risk of breast cancer (OR = 1.20, 95% CI = 1.02 to 1.40). However, compared with BRCA1 mutation carriers who never used oral contraceptives, those who used oral contraceptives for at least 5 years had an increased risk of breast cancer (OR = 1.33, 95% CI = 1.11 to 1.60), as did those who used oral contraceptives before age 30 (OR = 1.29, 95% CI = 1.09 to 1.52), those who were diagnosed with breast cancer before age 40 (OR = 1.38, 95% CI = 1.11 to 1.72), and those who first used oral contraceptives before 1975 (OR = 1.42, 95% CI = 1.17 to 1.75). CONCLUSIONS: Among BRCA1 mutation carriers, women who first used oral contraceptives before 1975, who used them before age 30, or who used them for 5 or more years may have an increased risk of early-onset breast cancer. Oral contraceptives do not appear to be associated with risk of breast cancer in BRCA2 carriers, but data for BRCA2 carriers are limited.

Adolescent↗

PubMed2002

Significant contribution of large BRCA1 gene rearrangements in 120 French breast and ovarian cancer families.

Genetic linkage data have shown that alterations of the BRCA1 gene are responsible for the majority of hereditary breast-ovarian cancers. However, BRCA1 germline mutations are found much less frequently than expected, especially as standard PCR-based mutation detection approaches focus on point and small gene alterations. In order to estimate the contribution of large gene rearrangements to the BRCA1 mutation spectrum, we have extensively analysed a series of 120 French breast-ovarian cancer cases. Thirty-eight were previously found carrier of a BRCA1 point mutation, 14 of a BRCA2 point mutation and one case has previously been reported as carrier of a large BRCA1 deletion. The remaining 67 cases were studied using the BRCA1 bar code approach on combed DNA which allows a panoramic view of the BRCA1 region. Three additional rearrangements were detected: a recurrent 23.8 kb deletion of exons 8-13, a 17.2 kb duplication of exons 3-8 and a 8.6 kb duplication of exons 18-20. Thus, in our series, BRCA1 large rearrangements accounted for 3.3% (4/120) of breast-ovarian cancer cases and 9.5% (4/42) of the BRCA1 gene mutation spectrum, suggesting that their screening is an important step that should be now systematically included in genetic testing surveys.

Adult↗