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ObjectiveTo evaluate the role of different specific types of germline breast cancer susceptibilityBRCAmutations on the age of onset of high grade serous ovarian cancer.MethodsThis was a multicenter, international, retrospective cohort of 474 patients diagnosed with recurrent or newly diagnosed high grade serous ovarian cancer, with known germline mutations inBRCA1/2genes, treated between January 2011 and December 2020 in three academic centers in Europe. Patients were classified into four groups related to the type ofBRCA1/2genes mutation: frameshift, missense, nonsense, and splicing. Data from patients with splicing mutations were removed from the analysis because of the small numbers. The other three groups were compared.ResultsExcluding the 29 patients with a splicing mutation, 474 patients were enrolled: 309 (65.2%) with frameshift mutations, 102 (21.5%) with nonsense mutations, and 63 (13.3%) with missense mutations. TheBRCA1gene was affected in 324 (68.4%) cases, whileBRCA2was involved in 150 (31.6%) women (p=0.06). We found a difference of more than 5 years in the age of onset of high grade serous ovarian cancer betweenBRCA1andBRCA2patients (mean 53.3 years vs 58.4 years; p=0.001), with a mean age of 55.1 years. Patients with nonsense germline mutations had the youngest age of onset, while women with frameshift mutations had the oldest age of onset of high grade serous ovarian cancer (mean 52.2 years vs mean 55.9 years), both in theBRCA1andBRCA2subgroups. There was no statistically significant difference in age of onset between early and advanced groups (mean 55.8 years vs 55.0 years; p=0.55).ConclusionDifferent types of germlineBRCAmutations could determine different ages for onset of high grade serous ovarian cancer. If confirmed in larger series, this finding might have a clinical impact, potentially leading to a more tailored approach for risk reducing surgery for the prevention of high grade serous ovarian cancer.

DNA mismatch repair (MMR) is essential for correction of DNA replication errors. Germline mutations of the human MMR gene MLH1 are the major cause of Lynch syndrome, a heritable cancer predisposition. In the MLH1 protein, a non-conserved, intrinsically disordered region connects two conserved, catalytically active structured domains of MLH1. This region has as yet been regarded as a flexible spacer, and missense alterations in this region have been considered non-pathogenic. However, we have identified and investigated a small motif (ConMot) in this linker which is conserved in eukaryotes. Deletion of the ConMot or scrambling of the motif abolished mismatch repair activity. A mutation from a cancer family within the motif (p.Arg385Pro) also inactivated MMR, suggesting that ConMot alterations can be causative for Lynch syndrome. Intriguingly, the mismatch repair defect of the ConMot variants could be restored by addition of a ConMot peptide containing the deleted sequence. This is the first instance of a DNA mismatch repair defect conferred by a mutation that can be overcome by addition of a small molecule. Based on the experimental data and AlphaFold2 predictions, we suggest that the ConMot may bind close to the C-terminal MLH1-PMS2 endonuclease and modulate its activation during the MMR process.

IntroductionLynch Syndrome (LS) represents the hereditary condition that is most frequently associated with endometrial cancer (EC). The aim of this study is to assess the presence of Lynch Syndrome (LS) in young women with mismatch repair (MMR)-deficient atypical endometrial hyperplasia (AEH) and non-myoinvasive FIGO G1 endometrioid EC and its possible impact on the outcome of conservative treatment.MethodsSix MMR-deficient cases identified from a previous cohort of 69 conservatively treated patients were selected to be screened for germline mutations in MMR genes. In each patient, the outcomes of conservative treatment for AEH and EEC, including response, relapse, progression, and pregnancy, were assessed.ResultsFive out of 6 patients underwent genetic test for LS. Three out of these 5 patients showed a positive genetic test. Patient 1 showed the c.942 + 2 T>A heterozygous variant of MSH2 mutation; after 12 months of complete response, she had relapse and progression of disease. Patient 4 showed the c.2459-1G>C variant of MSH2 mutation; after complete response, she failed to achieve pregnancy; she had relapse after 24 months and underwent hysterectomy. Patient 6 showed the c.803 + 1 heterozygous variant of PMS2 mutation; she had relapse of disease after 18 months from the first complete response and then underwent hysterectomy.ConclusionsIn this series, 3 out of 6 women with MMR-deficiency had LS. None of the patients achieved pregnancy, and those who responded to treatment had subsequent relapse of disease. Patients undergoing fertility-sparing treatment for atypical endometrial hyperplasia and endometrial cancer should perform MMR immunohistochemical analysis in order to screen LS.

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant disorder caused, in more than 80% of cases, by mutations of either the endoglin (

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant disorder caused, in more than 80% of cases, by mutations of either the endoglin (ENG) or the activin A receptor-like type 1 (ACVRL1) gene. Several hundred variants have been identified in these HHT-causing genes, including deletions, missense and nonsense mutations, splice defects, duplications, and insertions. In this study, we have analyzed retrospectively collected images of magnetic resonance angiographies (MRA) of the brain of HHT patients, followed at the HHT Center of our University Hospital, and looked for the distribution of cerebrovascular phenotypes according to specific gene variants. We found that cerebrovascular malformations were heterogeneous among HHT patients, with phenotypes that ranged from classical arteriovenous malformations (AVM) to intracranial aneurysms (IA), developmental venous anomalies (DVA), and cavernous angiomas (CA). There was also wide heterogeneity among the variants of the ENG and ACVRL1 genes, which included known pathogenic variants, variants of unknown significance, variants pending classification, and variants which had not been previously reported. The percentage of patients with cerebrovascular malformations was significantly higher among subjects with ENG variants than ACVRL1 variants (25.0% vs. 13.1%, p < 0.05). The prevalence of neurovascular anomalies was different among subjects with different gene variants, with an incidence that ranged from 3.3% among subjects with the c.1231C > T, c.200G > A, or c.1120C > T missense mutations of the ACVRL1 gene, to 75.0% among subjects with the c.1435C > T missense mutation of the ACVRL1 gene. Further studies and larger sample sizes are required to confirm these findings.

This review provides a comprehensive update on recent evidence regarding gynecologic tumors associated with Lynch Syndrome (LS). Endometrial cancer (EC) and ovarian cancer (OC) are the first and second most common gynecologic malignancies in developed countries, respectively, and LS is estimated to be the hereditary cause in 3% of both EC and OC. Despite the increasing evidence on LS-related tumors, few studies have analyzed the outcomes of LS-related EC and OC stratified by mutational variant. This review aims to provide a comprehensive overview of the literature and comparison between updated international guidelines, to help outline a shared pathway for the diagnosis, prevention, and management of LS. Through the widespread adoption of the immunohistochemistry-based Universal Screening, LS diagnosis and identification of mutational variants could be standardized and recognized by international guidelines as a feasible, reproducible, and cost-effective method. Furthermore, the development of a better understanding of LS and its mutational variants will support our ability to better tailor EC and OC management in terms of prophylactic surgery and systemic treatment in the light of the promising results shown by immunotherapy.

INTRODUCTION Surgical management of breast cancer patients carrying pathogenic variants (PV) on breast cancer genes (BRCA) 1 and 2 has changed throughout the last decade due to growing availability of genetic testing, and has shifted towards the diffusion of bilateral mastectomy. Today's scenario however is in further evolution because of emerging data that suggest a personalized modulation of treatment. In this work we aimed to gather recent evidence supporting a prophylactic or conservative surgical approach in order to define the state of the art in today's treatment of BRCA carriers with breast cancer. EVIDENCE ACQUISITION We reviewed the literature to identify studies providing evidence on surgical treatment in breast cancer patients with BRCA 1 and 2 PVs. We included articles comparing outcomes between patients undergoing breast conserving surgery (BCS) and mastectomy, and articles investigating contralateral risk-reducing mastectomy (CRRM), with a particular focus on recent literature. International guidelines were also reviewed. EVIDENCE SYNTHESIS Optimal surgical management of BRCA PV carriers with breast cancer remains controversial. While the introduction of routine genetic testing has initially led surgeons to favor more radical treatments, recent literature provides evidence that a conservative approach is safe and feasible in selected cases. Guidelines are heterogeneous and provide guidance without constraining the surgeon. CONCLUSIONS Patients should undergo adequate genetic and surgical counseling in order to receive the best tailored surgical treatment. Because guidelines vary in different countries and provide no definite protocol, they highlight the importance of accurate surgical planning. Clinical, familial and psychosocial factors should be taken into account when approaching a BRCA PV carrier with breast cancer, in order to guarantee the best evidence-based patient care in an era of personalized treatment.

An expert consensus panel convened by the Italian Association for Inherited and Familial Gastrointestinal Tumors (Associazione Italiana per lo Studio della Familiarita ed Ereditarieta dei Tumori Gastrointestinali, AIFEG) reviewed the literature and agreed on a number of position statements regarding the definition and management of polyposis coli without an identified pathogenic mutation on the APC or MUTYH genes, defined in the document as NAMP (non-APC/MUTYH polyposis).

Genomic testing expansion is accompanied by an increasing need for genetic counselling and intrafamilial communication. Genetic counselling can play an important role in facilitating intrafamilial communication and relationships. We conducted a cross-sectional, multicenter study including 252 Italian women, using a questionnaire divided in two sections, the first one to be filled after the pre-test counselling and the second after receiving BRCA test results. We assessed the factors influencing intrafamilial disclosure of genetic information for hereditary breast and ovarian cancer, family members with whom probands are more prone to share genetic information, and the perceived understanding of information received by counselees during genetic counselling. Women were accompanied to the counselling more often by their husband/partner. Among those with a positive BRCA test result, 49% intended to communicate it to their offspring and 27% to their husband/partner. Younger women, those living with their husband/partner, and those who described family communication as open/profound and spontaneous/sincere had a higher probability of being accompanied during genetic counselling and discuss about it with relatives. Spontaneous/sincere or open/profound family communication and joyful/happy familial relationships were associated with the decision to undergo genetic testing as a responsibility towards relatives. Women had a good understanding of counselling contents (mean score 9.27 in a scale 1–10). Genetic counselling providers should consider that genetic information disclosure does not depend only on the clarity of the information provided, but also on pre-existing intrafamilial communication and relationships, family structure and marital status, indicating the need for a personalised approach accounting for these factors.

One of the main factors influencing the clinical utility of genetic tests for cancer predisposition is the ability to provide actionable classifications (ie pathogenic or benign). However, a large fraction of the variants identified in cancer predisposing genes (CPGs) are of uncertain significance (VUS), and cannot be used for clinical purposes either to identify individuals at risk or to drive treatment. Here we analyze the current status of VUS identification in a subset of 24 CPGs included by the American College of Medical Genetics/Association for Molecular Pathology in the list of genes that should be considered for the return of incidental findings. To this purpose we retrieved published literature using different search strings according to the frequency of the condition and we extracted corresponding data from ClinVar. The total number of VUS has not decreased with time, due to widespread multigene panel testing, and the relative yield of VUS compared to pathogenic variants is higher in more recent studies, which tend to involve series not selected for the presence of specific high risk criteria. In addition, only few studies adopt gene specific interpretation criteria when these are available. Despite the large yield of VUS associated with multigene testing, the data obtained from such studies can be very useful for variant classification, especially for those variants that are more likely to be benign, since these are expected to be detected more frequently in a population that does not show gene specific manifestations. In addition, wider use of gene specific interpretation criteria should be promoted in order to optimize the interpretation process.

8-Oxoguanine, a common mutagenic DNA lesion, generates G:C > T:A transversions via mispairing with adenine during DNA replication. When operating normally, the MUTYH DNA glycosylase prevents 8-oxoguanine-related mutagenesis by excising the incorporated adenine. Biallelic MUTYH mutations impair this enzymatic function and are associated with colorectal cancer (CRC) in MUTYH-Associated Polyposis (MAP) syndrome. Here, we perform whole-exome sequencing that reveals a modest mutator phenotype in MAP CRCs compared to sporadic CRC stem cell lines or bulk tumours. The excess G:C > T:A transversion mutations in MAP CRCs exhibits a novel mutational signature, termed Signature 36, with a strong sequence dependence. The MUTYH mutational signature reflecting persistent 8-oxoG:A mismatches occurs frequently in the APC, KRAS, PIK3CA, FAT4, TP53, FAT1, AMER1, KDM6A, SMAD4 and SMAD2 genes that are associated with CRC. The occurrence of Signature 36 in other types of human cancer indicates that DNA 8-oxoguanine-related mutations might contribute to the development of cancer in other organs., Graphical Abstract Image 1, Highlights • A modest mutator phenotype in MUTYH-defective colorectal cancer • Novel mutational signature of G>T mutations from persisting 8-oxoguanine:A mispair • This mutational signature is present in oncogenes/tumor suppressor associated with colorectal cancer • The mutational signature allows identifying a role for 8-oxoguanine-related mutations in other types of human cancer. Viel et al. identifies by exome-sequencing a mutational signature in colorectal cancer defective in the MUTYH DNA glycosylase, a DNA repair gene preventing 8-oxoguanine-related mutagenesis. A strong sequence dependence of G > T transversions characterizes this mutational fingerprint and unveils the contribution of persistent 8-oxoG:A mismatches in human cancer.

Muir–Torre syndrome (MTS) is clinically characterized by the occurrence of skin, usually sebaceous, and visceral tumors in the same individual. The most common underlying mechanism is a constitutional defect of the mismatch repair (MMR) genes that cause Lynch syndrome (LS). Herewithin we report on a 76 years-old male patient heterozygous for a pathogenic MSH2 missense substitution who presented with a striking cutaneous phenotype in the absence of typical LS visceral tumors. The patient developed 20 skin tumors, including sebaceous adenomas/carcinomas and keratoacanthomas. Two skin tumors showed immunohistochemical loss of MSH2 and MSH6 expression. There was no apparent family history of neoplasia. Based on the variable involvement of the skin and internal organs, we suggest that the definition of tumor associations that are often observed as variants of inherited tumor syndromes, such as MTS, should be guided by the underlying molecular bases. In addition, the presence of multiple sebaceous tumors, especially if showing MMR deficiency, appears to be a very strong indicator of a constitutional MMR gene defect. The reasons underlying the high phenotypic variability of cutaneous phenotypes associated with constitutional MMR defects are yet to be determined.

Phelan-McDermid syndrome (PMS) is a rare neurodevelopmental disorder caused by rearrangements on chromosome 22q13.3 or sequence variants in SHANK3. Individuals with PMS caused by a 22q terminal deletion and a ring chromosome are at increased risk for Neurofibromatosis type 2 (NF2). However, the prevalence of NF2 in individuals with PMS and a r (22) is unknown. Individuals with PMS and a r (22) chromosome evaluated at the Greenwood Genetic Center (GGC) or by international collaborators, or identified through the PMS International Registry (PMSIR) were contacted and participated in a clinical questionnaire. Forty-four families completed the questionnaire and consented for the study. Of the individuals with a r (22), 7 (16%) carried a diagnosis of NF2. The average age of diagnosis of r (22) was 18 years old in individuals with NF2 and three years old in individuals without NF2 (p-value

Genomic testing expansion is accompanied by an increasing need for genetic counselling and intrafamilial communication. Genetic counselling can play an important role in facilitating intrafamilial communication and relationships. We conducted a cross-sectional, multicenter study including 252 Italian women, using a questionnaire divided in two sections, the first one to be filled after the pre-test counselling and the second after receiving BRCA test results. We assessed the factors influencing intrafamilial disclosure of genetic information for hereditary breast and ovarian cancer, family members with whom probands are more prone to share genetic information, and the perceived understanding of information received by counselees during genetic counselling. Women were accompanied to the counselling more often by their husband/partner. Among those with a positive BRCA test result, 49% intended to communicate it to their offspring and 27% to their husband/partner. Younger women, those living with their husband/partner, and those who described family communication as open/profound and spontaneous/sincere had a higher probability of being accompanied during genetic counselling and discuss about it with relatives. Spontaneous/sincere or open/profound family communication and joyful/happy familial relationships were associated with the decision to undergo genetic testing as a responsibility towards relatives. Women had a good understanding of counselling contents (mean score 9.27 in a scale 1-10). Genetic counselling providers should consider that genetic information disclosure does not depend only on the clarity of the information provided, but also on pre-existing intrafamilial communication and relationships, family structure and marital status, indicating the need for a personalised approach accounting for these factors.

The multifactorial likelihood analysis method has demonstrated utility for quantitative assessment of variant pathogenicity for multiple cancer syndrome genes. Independent data types currently incorporated in the model for assessing BRCA1 and BRCA2 variants include clinically calibrated prior probability of pathogenicity based on variant location and bioinformatic prediction of variant effect, co-segregation, family cancer history profile, co-occurrence with a pathogenic variant in the same gene, breast tumor pathology, and case-control information. Research and clinical data for multifactorial likelihood analysis were collated for 1,395 BRCA1/2 predominantly intronic and missense variants, enabling classification based on posterior probability of pathogenicity for 734 variants: 447 variants were classified as (likely) benign, and 94 as (likely) pathogenic; and 248 classifications were new or considerably altered relative to ClinVar submissions. Classifications were compared with information not yet included in the likelihood model, and evidence strengths aligned to those recommended for ACMG/AMP classification codes. Altered mRNA splicing or function relative to known nonpathogenic variant controls were moderately to strongly predictive of variant pathogenicity. Variant absence in population datasets provided supporting evidence for variant pathogenicity. These findings have direct relevance for BRCA1 and BRCA2 variant evaluation, and justify the need for gene-specific calibration of evidence types used for variant classification., Ohio State University Comprehensive Cancer Center Barretos Cancer Hospital. Grant Number: FINEP ‐ CT‐INFRA (02/2010) Breast Cancer Foundation of New Zealand Canadian Institutes of Health Research. Grant Number: PSR‐SIIRI‐701 Cancer Research UK. Grant Numbers: C8197/A16565, C5047/A8384, C1281/A12014, C12292/A11174, C1287/A10710, C1287/A10118, C1287/A16563, C5047/A10692, C5047/A15007 Department of Defence, USA. Grant Number: W81XWH‐10‐1‐0341 Helsinki University Hospital Research fund Scientific Foundation Asociación Española Contra el Cáncer Leiden University Medical Centre. Grant Number: Grant 30.925 Generalitat de Catalunya. Grant Numbers: PERIS_MedPerCan, URDCat, 2017SGR1282, 2017SGR496 Royal Society of New Zealand Cancer Council Victoria Netherlands Organization for Scientific Research (NWO). Grant Number: Grant 017.008.022 Breast Cancer Research Foundation Cancer Foundation of Western Australia EU H2020. Grant Number: 634935 Fundación Mutua Madrileña Seventh Framework Programme. Grant Numbers: 634935, 223175, 633784 Cancer Council South Australia Government of Galicia. Grant Number: Consolidation and structuring program: IN607B Cancer Council Tasmania Italian Association of Cancer Research. Grant Number: 15547 Queensland Cancer Fund AstraZeneca National Institute of Health (USA). Grant Numbers: 1U19 CA148065‐01, CA128978, CA192393, 1U19 CA148537, P50 CA1162091, CA116167, 1U19 CA148112 Newcastle University Dutch Cancer Society KWF. Grant Numbers: KWF/Pink Ribbon‐11704, UL2012‐5649 National Institute for Health Research. Grant Number: Manchester Biomedical Research centre (IS‐BRC‐1215 National Council of Technological and Scientific Development (CNPq) Instituto de Salud Carlos III. Grant Numbers: FIS PI15/00355, FIS PI13/01711, CIBERONC, FIS PI16/01218, PI16/00563 French National Institute of Cancer National Breast Cancer Foundation National Health and Medical Research Council. Grant Numbers: ID1061778, ID1104808 Carlos III National Health Centro de Investigación Biomédica en Red de Enferemdades Raras. Grant Number: ACCI 2016: ER17P1AC7112/2018 Cancer Council NSW Deutsche Krebshilfe. Grant Numbers: (#110837, #70111850 Fondazione Pisa. Grant Number: Grant “Clinical characterization of BRCA 1/2 Mis

Purpose. Desmoid-type fibromatosis is a benign fibrous neoplasia originating from connective tissue, fascial planes, and musculoaponeurotic structures of the muscles. Currently, there is no evidence-based treatment approach available for desmoid fibromatosis. In this article, a case of a patient in the pediatric age affected by desmoid fibromatosis localized in the orbit is presented. The aim of the article is to describe this unusual and rare location for the desmoid fibromatosis and outline the principle phases in the decision-making process and the therapeutic alternatives for a patient affected by desmoid fibromatosis. Methods. The protocol of this review included study objectives, search strategy, and selection criteria. The primary end point of this study was to analyze the head and neck desmoid fibromatosis. The secondary end point was to identify the available therapies and assess their specific indications. Results. The mean age of patients was 18.9 years ranging from 0 to 66, and 52% were female. A bimodal age distribution was observed, and two age peaks were identified: 0–14 years (57%) and 28–42 years (18%). The most common involved areas were the mandible (25%) followed by the neck (21%). In 86% of the cases, the treatment was the surgical resection of the disease, and only in 5% of the cases, the surgical resection was followed by adjuvant radiotherapy. Conclusion. The orbital location is extremely rare, especially in the pediatric population. The management of desmoid fibromatosis is based on the function preservation and the maintenance of a good quality of life, but in case of symptomatic patients or aggressive course of the disease or risk of functional damages, the surgical approach may be considered. Therapeutic alternatives to surgical resection are radiotherapy and systemic therapy.

The DNA glycosylase gene MBD4 safeguards genomic stability at CpG sites and is frequently mutated at coding poly-A tracks in mismatch repair (MMR)-defective colorectal tumors (CRC). Mbd4 biallelic inactivation in mice provided conflicting results as to its role in tumorigenesis. Thus, it is unclear whether MBD4 alterations are only secondary to MMR defects without functional consequences or can contribute to the mutator phenotype. We investigated MBD4 variants in a large series of hereditary/familial and sporadic CRC cases. Whereas MBD4 frameshifts were only detected in tumors, missense variants were found in both normal and tumor DNA. In CRC with double-MBD4/MMR and single-MBD4 variants, transition mutation frequency was increased, indicating that MBD4 defects may affect the mutational landscape independently of MMR defect. Mbd4-deficient mice showed reduced survival when combined with Mlh1-/- genotype. Taken together, these data suggest that MBD4 inactivation may contribute to tumorigenesis, acting as a modifier of MMR-deficient cancer phenotype.

Familial adenomatous polyposis has been the first form of inherited intestinal polyposis to be recognized. For a long time it has been considered the main polyposis syndrome, associated with an easily recognizable phenotype, with a marginal role attributed to a few very rare hamartomatous conditions. More recently, it has been gradually demonstrated that the intestinal polyposes encompass a range of conditions within a wide spectrum of disease severity, polyp histology, and extraintestinal manifestations. A growing number of genes and phenotypes has been identified, and heterogeneity of somatic molecular pathways underlying epithelial transformation in different syndromes and associated tumors has been documented. Increasing knowledge on the molecular bases and more widespread use of genetic tests has shown phenotypic overlaps between conditions that were previously considered distinct, highlighting diagnostic difficulties. With the advent of next generation sequencing, the diagnosis and the classification of these syndromes will be progressively based more on genetic testing results. However, the phenotypic variability documented among patients with mutations in the same genes cannot be fully explained by different expressivity, indicating a role for as yet unknown modifying factors. Until the latter will be identified, the management of patients with polyposis syndromes should be guided by both clinical and genetic findings.

Anterior pituitary aplasia (APA) is a very rare cause of congenital-onset multiple pituitary hormone deficiency (CO-MPHD). We report on molecular analysis and clinical follow-up of three previously reported cases of APA [Scommegna et al., 2004], who share a characteristic physical and neuropsychological profile. Mutation analysis of genes encoding transcription factors involved in pituitary development (PROP1, POUF1, HESX1, LHX3, and LHX4) did not demonstrate a any mutation. In order to identify the genetic cause underlying the phenotypes we performed an array-based comparative genomic hybridization (array-CGH), which showed a cryptic interstitial deletion of 9p (200 kb), including the TEK and MOBKL2B, in one patient. Although an apparently identical deletion was carried by the clinically normal father, we assumed that the patient's phenotype might be due to a recessive mutation in the other allele. However, sequence analysis of exons and splice junctions of these genes did not detect pathogenic or predisposing variants in the three patients. We suggest that the constellation of clinical signs in these patients constitutes a previously undescribed syndrome, whose genetic cause has yet to be identified.

The Simpson-Golabi-Behmel syndrome (SGBS) is an overgrowth condition comprising "coarseness" of facial traits, supernumerary nipples, congenital heart defects, polydactyly and fingernail hypoplasia, and an increased risk of neonatal death and later neoplasia. Psychomotor development is usually normal. The syndrome is caused by mutation/deletion of the X-linked gene GPC3. We describe a new case of SGBS, that led to the discovery of an extended family segregating a GPC3 mutation and, ultimately, of an affected relative forgotten, but not lost, in an anatomical museum, where he was classified as a macrosomic newborn, who was born probably around 1940 and died neonatally of unknown cause. This baby boy becomes the oldest case of SGBS on record.

Rubinstein–Taybi syndrome (RSTS) is a rare malformation disorder caused by mutations in the closely related CREBBP and EP300 genes, accounting respectively for up to 60 and 3% of cases. About 10% of CREBBP mutations are whole gene deletions often extending into flanking regions. Using FISH and microsatellite analyses as a first step in the CREBBP mutation screening of 42 Italian RSTS patients, we identified six deletions, three of which were in a mosaic condition that has not been previously reported in RSTS. The use of region-specific BAC clones and small CREBBP probes allowed us to assess the extent of all of the deletions by mapping their endpoints to genomic intervals of 5–10 kb. Four of our five intragenic breakpoints cluster at the 5′ end of CREBBP, where there is a peak of breakpoints underlying rearrangements in RSTS patients and tumors. The search for genomic motifs did not reveal any low-copy repeats (LCRs) or any greater density of repetitive sequences. In contrast, the percentage of interspersed repetitive elements (mainly Alu and LINEs in the CREBBP exon 2 region) is significantly higher than that in the entire gene or the average in the genome, thus suggesting that this characteristic may be involved in the region’s vulnerability to breaking and nonhomologous pairing. The FISH analysis extended to the EP300 genomic region did not reveal any deletions. The clinical presentation was typical in all cases, but more severe in the three patients carrying constitutional deletions, raising a question about the possible underdiagnosis of a few cases of mild RSTS.

A unique mutation of the MLH1 gene was recently reported in six families living in a small area of Northern Italy. The mutation consists in the insertion of a T base between nucleotides 2269 and 2270 (2269-2270insT), causing the synthesis of an unstable polypeptide. The mutation was not reported by other investigators or outside this small geographic area, thus suggesting a possible founder effect. The main purpose of this investigation was to investigate whether patients (and families) with the 2260-2270insT mutation show relevant clinical differences when compared with individuals with other MLH1 or MSH2 gene alterations.We identified hereditary non-polyposis colorectal cancer (HNPCC) families through the specialized colorectal cancer registry following a previously described multistep approach. In all, 58 HNPCC families were identified; of these, 38 were detected through the registry, and 20 were referred from other areas in Italy.Small differences were found in the main clinical and pathologic features; however, tumour burden per family tended to be higher in kindred sharing the founder mutation; in addition, multiple primaries (four or five different tumours in some subjects) were significantly more frequent in patients with the 2269-2270insT than in individuals with MSH2, MLH1 gene mutations or sporadic colorectal neoplasms. No significant difference in prognosis was found between patients with the founder mutation and those with other MLH1 or MSH2 mutations. Regardless of the type of mutation, neoplasms of the colon-rectum, stomach and endometrium represented nearly 80% of the tumour burden in families with HNPCC.A proclivity to multiple tumours arising in the same subject and a higher tumour burden per family were the most relevant findings observed in affected patients with the founder mutation compared with other MLH1 or MSH2 mutations. In general, the results of the study underline the difficulty in discriminating between Lynch I and Lynch II syndromes on the basis of specific molecular changes.

Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal-dominant disorder characterized by predisposition to colorectal cancer and extracolonic malignancies, frequent multiple primary tumors in the same patient, and early age of cancer onset. A main clinical variant of Lynch syndrome, Muir-Torre syndrome (MTS) is characterized by the association between one or more visceral malignancies, with at least one sebaceous skin tumor or keratoacanthoma. In our study, we have screened a cohort of 538 HNPCC patients, related to 57 HNPCC families, to detect sebaceous skin tumors and keratoacanthomas and the role of mismatch repair (MMR) genes, MLH1, MSH2, and MSH6, in their pathogenesis. Among the 57 HNPCC families, we have identified four MTS families and one suspected MTS family, in which sebaceous carcinoma was found in one HNPCC mutation carrier subject who did not show visceral malignancy. In four of these families, linked to two MLH1 mutations and to two MSH2 mutations, biomolecular characterization showed concordance among immunohistochemistry analysis and gene mutations. The evidences of our investigations show that MLH1 and MSH2 gene mutations have an equivalent etiopathological role both for Lynch syndrome and for MTS; hence, we propose a broadened clinical criteria for definition of Lynch syndrome that will include sebaceous adenoma, carcinoma, and keratoacanthoma.

The International Registry of Werner syndrome (www.wernersyndrome.org) has been providing molecular diagnosis of the Werner syndrome (WS) for the past decade. The present communication summarizes, from among 99 WS subjects, the spectrum of 50 distinct mutations discovered by our group and by others since the WRN gene (also called RECQL2 or REQ3) was first cloned in 1996; 25 of these have not previously been published. All WRN mutations reported thus far have resulted in the elimination of the nuclear localization signal at the C-terminus of the protein, precluding functional interactions in the nucleus; thus, all could be classified as null mutations. We now report two new mutations in the N-terminus that result in instability of the WRN protein. Clinical data confirm that the most penetrant phenotype is bilateral ocular cataracts. Other cardinal signs were seen in more than 95% of the cases. The median age of death, previously reported to be in the range of 46–48 years, is 54 years. Lymphoblastoid cell lines (LCLs) have been cryopreserved from the majority of our index cases, including material from nuclear pedigrees. These, as well as inducible and complemented hTERT (catalytic subunit of human telomerase) immortalized skin fibroblast cell lines are available to qualified investigators. Published 2006 Wiley-Liss, Inc.†

Mutation-predicting models can be useful when deciding on the genetic testing of individuals at risk and in determining the cost effectiveness of screening strategies at the population level. The aim of this study was to evaluate the performance of a newly developed genetic model that incorporates tumor microsatellite instability (MSI) information, called the AIFEG model, and in predicting the presence of mutations in MSH2 and MLH1 in probands with suspected hereditary non-polyposis colorectal cancer. The AIFEG model is based on published estimates of mutation frequencies and cancer penetrances in carriers and non-carriers and employs the program MLINK of the FASTLINK package to calculate the proband's carrier probability. Model performance is evaluated in a series of 219 families screened for mutations in both MSH2 and MLH1, in which 68 disease-causing mutations were identified. Predictions are first obtained using family history only and then converted into posterior probabilities using information on MSI. This improves predictions substantially. Using a probability threshold of 10% for mutation analysis, the AIFEG model applied to our series has 100% sensitivity and 71% specificity.

BACKGROUND: Germline mutations in the STK11/LKB1 gene cause Peutz-Jeghers syndrome, an autosomal-dominantly inherited condition characterized by mucocutaneous pigmentation, hamartomatous gastrointestinal polyposis, and an increased risk for various malignancies. We here report the results of the first Italian collaborative study on Peutz-Jeghers syndrome. AIMS: To assess cancer risks in a large homogenous cohort of patients with Peutz-Jeghers syndrome, carrying, in large majority, an identified STK11/LKB1 mutation. METHODS: One-hundred and nineteen patients with Peutz-Jeghers syndrome, ascertained in sixteen different Italian centres, were enrolled in a retrospective cohort study. Relative and cumulative cancer risks and genotype-phenotype correlations were evaluated. RESULTS: 36 malignant tumours were found in 31/119 (29 STK11/LKB1 mutation carriers) patients. The mean age at first cancer diagnosis was 41 years. The relative overall cancer risk was 15.1 with a significantly higher risk (p

Constitutional chromosome deletions can predispose to the development of cancer with the phenotypic characteristics of inherited cancer syndromes, when the deleted region encompasses a tumour suppressor gene. Examples of such conditions are represented by the cytogenetic deletions associated with retinoblastoma, Wilms tumour and familial adenomatous polyposis. So far, no constitutional deletions involving the genes implicated in hereditary non-polyposis colorectal cancer (HNPCC) have been identified. This may be at least partially because of the lack of distinctive phenotypic manifestations in HNPCC. We describe the first case of a constitutional microdeletion associated with HNPCC. Suspicion of a microdeletion was prompted by the association of mental retardation, postnatal growth deficiency, minor congenital anomalies and early onset (37 years) sporadic colon cancer. The patient was found to harbour a microdeletion within chromosome 2p16-p21, including the MSH2 gene. Since there are very few reports of deletions of the 2p16-p21 region, our observation sets the grounds for the definition of a novel multiple congenital anomaly/mental retardation/cancer microdeletion syndrome.

Hereditary nonpolyposis colorectal cancer (HNPCC) is frequently associated with constitutional mutations in a class of genes involved in DNA mismatch repair. We identified 32 kindreds, with germline mutations in one of three genes hMSH2, hMLH1 or hMSH6. In this study, we purposed to evaluate how many high-risk individuals in each family underwent genetic testing: moreover, we assessed how many mutation-positive unaffected individuals accepted colonoscopic surveillance and the main findings of the recommended follow-up. Families were identified through a population-based registry, or referred from other centres. Members of the families were invited for an education session with two members of the staff. When a kindred was consistent with HNPCC, neoplastic tissues were examined for microsatellite instability (MSI) and immunohistochemical expression of MSH2, MLH1 and MSH6 proteins. Moreover, constitutional mutations were searched by SSCP or direct sequencing of the whole genomic region. Of the 164 subjects assessed by genetic testing, 89 were gene carriers (66 affected - that is, with HNPCC-related cancer diagnosis - and 23 unaffected) and 75 tested negative. Among the 23 unaffected gene carriers, 18 (78.3%) underwent colonoscopy and four declined. On a total of 292 first degree at risk of cancer, 194 (66.4%) did not undergo genetic testing. The main reasons for this were: (a) difficulty to reach family members at risk, (b) lack of collaboration, (c) lack of interest in preventive medicine or 'fatalistic' attitude towards cancer occurrence. The number of colorectal lesions detected at endoscopy in gene carriers was significantly (P0.01) higher than in controls (noncarriers). We conclude that a large fraction of high-risk individuals in mutation-positive HNPCC families does not undergo genetic testing, despite the benefits of molecular screening and endoscopic surveillance. This clearly indicates that there are still barriers to genetic testing in HNPCC, and that we are unable to provide adequate protection against cancer development in these families.

Hereditary nonpolyposis colorectal cancer (HNPCC) is a cancer-predisposing condition caused by inactivating mutations in at least four genes (MSH2, MLH1, MSH6, and PMS2) belonging to the mismatch repair system. At present, availability of the microsatellite instability (MSI) test allows screening of a relevant fraction of patients with a constellation of features suggestive of HNPCC. By analogy with several other genetic disorders, it is clearly emerging that the term HNPCC encompasses a wide spectrum of different clinical presentations, including Muir-Torre syndrome, Turcot syndrome, and the neurofibromatosis-hematological malignancy association. Notwithstanding the remarkable genetic and allelic heterogeneity, a few consistent phenotype-genotype associations can be recognized. Mutations in the MSH2 gene entail higher risks of developing cancer, including extraintestinal ones, than MLH1 alterations. MSH2 also accounts for most cases of Muir-Torre syndrome, which is characterized by the presence of sebaceous skin tumors. The few known PMS2 mutations show a striking association with the presence of gliomas, which are the hallmark of the Turcot variant of HNPCC. Homozygotes for mismatch repair gene mutations present with stigmata of neurofibromatosis 1 and usually die in childhood due to a variety of leukemias and lymphomas. While such correlations are being defined, the underlying reasons have only partially been elucidated, and may include heterogeneous gene functions and properties; types of mutation, some of which may exert dominant negative effects; and genetic and environmental modifiers.

Mutations of the mismatch repair (MMR) genes MLH1 and MSH2 are associated with hereditary nonpolyposis colorectal cancer (HNPCC), a highly penetrant autosomal dominant condition characterized by hypermutability of short tandemly repeated sequences in tumor DNA. Mutations of another MMR gene, MSH6, seem to be less common than MLH1 and MSH2 defects, and have been mostly observed in atypical HNPCC families, characterized by a weaker tumor family history, higher age at disease onset, and low degrees of microsatellite instability (MSI), predominantly involving mononucleotide runs. We have investigated the MSH6 gene sequence in the peripheral blood of 4 HNPCC and 20 atypical HNPCC probands. Two frameshift mutations within exon 4 were detected in 2 patients. One mutation was found in a proband from a typical HNPCC family, who had developed a colorectal cancer (CRC), a gastric cancer and a rectal adenoma. The CRC and the adenoma showed mild MSI limited to mononucleotide tracts, while the gastric carcinoma was microsatellite stable. The other mutation was detected in an atypical HNPCC proband, whose CRC showed widespread MSI involving both mono- and dinucleotide repeats. The phenotypic variability associated with MSH6 constitutional mutations represents a complicating factor for the optimization of strategies aimed at identifying candidates to MSH6 genetic testing.

Double pituitary adenomas represent up to 2.6 % of pituitary adenomas in large surgical series and up to 3.3 % of patients with Cushing’s disease have been found to have double or multiple pituitary adenomas. We report the case of a 60-year-old male patient whose medical history began in 2002 with erectile dysfunction; hyperprolactinemia was found and MRI showed a 6-mm area of delayed enhancement in the lateral portion of the right pituitary lobe. Treatment with cabergoline was started with normalization of prolactin levels; the following MRI, performed in 2005 and 2008, showed shrinkage of the pituitary lesion. In 2005, the patient began to manifest weight gain, hypertension, and facial plethora, but no further evaluations were done. In January 2010, the patient came to our attention and underwent multiple tests that suggested Cushing’s disease. A new MRI was negative. Bilateral inferior petrosal sinus sampling showed significant pituitary-to-peripheral ratio and, in May 2010, the patient underwent exploratory pituitary surgery with evidence of a 1–2-mm white-coloured midline area compatible with pituitary adenoma that was surgically removed. Post-operatively, the patient’s clinical conditions improved with onset of secondary hypoadrenalism. The histologic examination confirmed a pituitary adenoma (immunostaining was found to be positive for ACTH and negative for prolactin). We report the case of an ACTH-producing microadenoma metachronous to a prolactin secreting microadenoma although not confirmed histologically, shrunk by medical treatment. A review of data in the literature regarding double or multiple pituitary adenomas has also been done.

MUTYH-associated polyposis (MAP) is an autosomal recessive adenomatous polyposis caused by biallelic germline mutations of the base-excision-repair gene MUTYH. In MAP patients of European origin, the combined allele frequency of the mutations p.Tyr179Cys and p.Gly396Asp ranges between 50 and 82%, while these mutations have not been identified in Far Eastern Asian populations, supporting the hypothesis that a founder effect has occurred at some point in European history. To investigate the natural history of the two common European MUTYH alleles, we genotyped six gene-flanking microsatellite markers in 80 unrelated Italian and German MAP patients segregating one or both mutations and calculated their age in generations (g) by using DMLE+2.2 software. Three distinct common haplotypes, one for p.Tyr179Cys and two for p.Gly396Asp, were identified. Estimated mutation ages were 305 g (95% CS: 271–418) for p.Tyr179Cys and 350 g (95% CS: 313–435) for p.Gly396Asp. These results provide evidence for strong founder effects and suggest that the p.Tyr179Cys and p.Gly396Asp mutations derive from ancestors who lived between 5–8 thousand years and 6–9 thousand years B.C., respectively.

Head and neck paragangliomas (HNPGLs) are neural crest-derived tumors. In comparison with paragangliomas located in the abdomen and the chest, which are generally catecholamine secreting (sPGLs) and sympathetic in origin, HNPGLs are, in fact, parasympathetic in origin and are generally nonsecreting. Overall, 79 consecutive patients with HNPGL were examined for mutations in SDHA, SDHB, SDHC, SDHD, SDHAF2, VHL, MAX, and TMEM127 genes by PCR/sequencing. According to a detailed family history (FH) and clinical, laboratory (including metanephrines), and instrumental examinations, patients were divided into three groups: a) patients with a positive FH for HNPGL (index cases only), b) patients with a negative FH and multiple HNPGLs (synchronous or metachronous) or HNPGL associated with an sPGL, and c) patients with negative FH and single HNPGL. The ten patients in group a) proved to be SDHD mutation carriers. The 16 patients in group b) proved to be SDHD mutation carriers. Among the 53 patients in group c), ten presented with germ-line mutations (three SDHB, three SDHD, two VHL, and two SDHAF2). An sPGL was found at diagnosis or followed up in five patients (6.3%), all were SDHD mutation carriers. No SDHC, SDHA, MAX, and TMEM127 mutations were found. In SDHD mutation carriers, none of the patients affected by HNPGL associated with sPGL presented missense mutations. In conclusion, a positive FH or the presence of multiple HNPGLs is a strong predictor for germ-line mutations, which are also present in 18.8% of patients carefully classified as sporadic. The most frequently mutated gene so far is SDHD but others, including SDHB, SDHAF2, and VHL, may also be affected.

A large majority of constitutional mutations in hereditary non-polyposis colorectal cancer (HNPCC) are because of the MHL 1 or MSH 2 genes. In a lower fraction of cases, another gene of the mismatch repair (MMR) machinery, MSH6, may be responsible. Families with MSH6 mutations are difficult to recognize, as microsatellite instability (MSI) may not be detectable and immunohistochemistry (IHC) may give ambiguous results. In the present study, we proposed (i) to determine the frequency of MSH6 mutations in a selected population of colorectal cancer patients obtained from a tumor registry, (ii) to assess whether IHC is a suitable tool for selecting and identifying MSH6 mutation carriers. One hundred neoplasms of the large bowel from suspected HNPCC families were analyzed for MSI (BAT 25 and BAT 26 markers) and immunohistochemical expression of the MSH6 protein. We found on 12 tumors (from different families) showing instability or lack of MSH6 expression. Among these, four potentially pathogenic MSH6 mutations were detected (del A at 2984; del TT at 3119; del AGG cod 385; and del CGT cod 1242) by direct gene sequencing. These represented 12.9% of all families with constitutional mutations of the DNA MMR genes. Thus, some 5% of all HNPCC families are featured by constitutional mutation of the MSH6 gene. This appears, however, as a minimum estimate; routine use of IHC and the study of large numbers of individuals and families with little or no evidence of Lynch syndrome might reveal that mutation of this gene account for a large fraction of HNPCC.

The PTPN11 gene encodes SHP-2, a widely expressed cytoplasmic protein tyrosine phosphatase functioning as a signaling transducer. Germ-line PTPN11 mutations cause Noonan syndrome (NS), a developmental disorder characterized by an increased risk of malignancies. Recently, a novel class of activating mutations in PTPN11 has been documented as a somatic event in a heterogeneous group of leukemias. Because of the relatively higher prevalence of certain solid tumors in children with NS and the positive modulatory function of SHP-2 in RAS signaling, a wider role for activating PTPN11 mutations in cancer has been hypothesized. Here, we screened a number of solid tumors, including those documented in NS or in which deregulated RAS signaling occurs at significant frequency, for PTPN11 mutations. No disease-associated mutation was identified in rhabdomyosarcoma (n = 13), neuroblastoma (n = 32), melanoma (n = 50), thyroid (n = 85), and colon (n = 48) tumors; a novel missense change, promoting an increased basal phosphatase activity of SHP-2, was observed in one glioma specimen. Our data document that deregulated SHP-2 function does not represent a major molecular event in pediatric and adult tumors, further supporting our previous evidence indicating that the oncogenic role of PTPN11 mutations is cell-context specific.

We report the clinicopathological, genetic, and immunohistochemical characterization of an atypical Turcot syndrome (TS) family with small bowel cancer. The tumor family history of a patient with cafe-au-lait spots (CALS) and early onset adenomas, duodenal cancer, and glioblastoma was positive for colonic adenoma (mother), jejunal (maternal grandfather), lung (father), and colorectal (paternal uncle) cancers. PMS2 genetic testing identified the nonsense 1951C>T (Q643X) and the missense 161C>T (S46I) mutations. PMS2 expression was absent in the proband's duodenal cancer with high microsatellite instability. The normal cells also displayed no PMS2 expression and some degree of instability. Our findings point out the association between PMS2 and TS, and support the hypothesis that patients with a few polyps, small bowel tumors with a very early onset, glioblastoma, and CALS should be considered as a variant of hereditary nonpolyposis colorectal cancer. A recessive model of inheritance caused by compound heterozygous mutations was consistent with the observed severe clinical phenotype and has important implications for predicting cancer risk in both the proband and his relatives.

BACKGROUND The Muir–Torre syndrome (MTS) is an autosomal-dominant genodermatosis characterized by the presence of sebaceous gland tumors, with or without keratoacanthomas, associated with visceral malignancies. A subset of patients with MTS is considered a variant of the hereditary nonpolyposis colorectal carcinoma, which is caused by mutations in mismatch-repair genes. The objective of the current study was to evaluate whether a combined clinical, immunohistochemical, and biomolecular approach could be useful for the identification of Muir–Torre syndrome among patients with a diagnosis of sebaceous tumors and keratoacanthomas. METHODS The authors collected sebaceous skin lesions and keratoacanthomas recorded in the files of the Pathology Department of the University of Modena during the period 1986–2000. Through interviews and examination of clinical charts, family trees were drawn for 120 patients who were affected by these skin lesions. RESULTS Seven patients also were affected by gastrointestinal tumors, thus meeting the clinical criteria for the diagnosis of MTS. In the MTS families, a wide phenotypic variability was evident, both in the spectrum of visceral tumors and in the type of skin lesions. Microsatellite instability was found in five MTS patients: These patients showed concordance with immunohistochemical analysis; moreover, a constitutional mutation in the MSH2 gene was found in 1 patient. Lack of expression of MSH2/MSH6 or MLH1 proteins was evident in the skin lesions and in the associated internal malignancies of 3 patients and 2 patients with MTS, respectively. CONCLUSIONS The clinical, biomolecular, and immunohistochemical characterization of sebaceous skin lesions and keratoacanthomas may be used as screening for the identification of families at risk of MTS, a disease that is difficult to recognize and diagnose. Cancer 2005. © 2005 American Cancer Society.

Objective: Identification of clinical and molecular characteristics associated with constitutional MLH1 and MSH2 mutations and definition of a stepwise strategy for the selection of colorectal cancer (CRC) patients amenable to MLH1 and MSH2 genetic testing. Methods: 90 unrelated CRC patients were initially selected on the basis of either familial or early onset occurrence of CRC. They were screened for the presence of constitutional MLH1 and MSH2 mutations and for microsatellite instability (MSI). Results: 16 pathogenetic mutations (9 MLH1 and 7 MSH2) were identified in 41% of Amsterdam hereditary nonpolyposis colorectal cancer (HNPCC) families, 5% of suspected HNPCC families, and 14% of sporadic early-onset CRC patients. The presence of the mutations correlated with MSI, with early age of onset and proximal location of the tumor, and with the presence of some extracolonic tumors of the HNPCC spectrum and/or multiple tumors in the family. Conclusions: Evaluation of clinical and molecular characteristics is useful for the identification of candidates to MLH1 and MSH2 mutational analysis and allows the application of a rational approach to genetic testing.

In this study we examined a series of 52 patients belonging to hereditary nonpolyposis colorectal cancer (HNPCC) or HNPCC-related families, all who had previously tested negative for mismatch repair (MMR) gene point mutations. Southern blot mutational screening of MLH1 and MSH2 genes was carried out with the aim of detecting large genomic rearrangements and of identifying the molecular mechanisms underlying the inactivation of the MMR genes. Three patients had abnormal restriction patterns and were found to carry distinct MLH1 internal deletions. Long-range PCRs identified the loss of DNA tracts spanning exon 6 (about 2.4 kb in proband A-AV20 and 0.8 kb in proband A-PD5) and exon 3 (about 2.5 kb in proband R-RM2). In A-AV20 the breakpoints occurred into identical 33-bp regions in introns 5 and 6 and a mechanism of classical Alu-mediated homologous recombination was evident. Also, in patient A-PD5 the breakpoints were located in these introns, but without direct involvement of repetitive sequences. In patient R-RM2 the breakpoints were located within repetitive L1 elements with poor homology in intron 2 and 3 and the rearranged allele was characterized by a complex insertion deletion (delCCinsACATAGTA), giving rise to a palindromic CTTAACATAGTATGTTAAG sequence in proximity of the fusion site. This study confirms that genomic rearrangements are an important component of the spectrum of MMR mutations. Although Alu repeats are likely to be implicated in the majority of cases, different molecular mechanisms may also be responsible for the observed MLH1 intragenic deletions. In particular, HNPCC resulting from L1-mediated recombination has been identified as a novel mechanism for MMR inactivating mutation.