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Lynch syndrome (LS) is an autosomal dominant disorder caused by a defect in one of the DNA mismatch repair genes: MLH1, MSH2, MSH6 and PMS2. In the last 15 years, an increasing number of patients have been described with biallelic mismatch repair gene mutations causing a syndrome referred to as 'constitutional mismatch repair-deficiency' (CMMR-D). The spectrum of cancers observed in this syndrome differs from that found in LS, as about half develop brain tumours, around half develop digestive tract cancers and a third develop haematological malignancies. Brain tumours and haematological malignancies are mainly diagnosed in the first decade of life, and colorectal cancer (CRC) and small bowel cancer in the second and third decades of life. Surveillance for CRC in patients with LS is very effective. Therefore, an important question is whether surveillance for the most common CMMR-D-associated cancers will also be effective. Recently, a new European consortium was established with the aim of improving care for patients with CMMR-D. At a workshop of this group held in Paris in June 2013, one of the issues addressed was the development of surveillance guidelines. In 1968, criteria were proposed by WHO that should be met prior to the implementation of screening programmes. These criteria were used to assess surveillance in CMMR-D. The evaluation showed that surveillance for CRC is the only part of the programme that largely complies with the WHO criteria. The values of all other suggested screening protocols are unknown. In particular, it is questionable whether surveillance for haematological malignancies improves the already favourable outcome for patients with these tumours. Based on the available knowledge and the discussions at the workshop, the European consortium proposed a surveillance protocol. Prospective collection of all results of the surveillance is needed to evaluate the effectiveness of the programme. [ABSTRACT FROM AUTHOR]

Birt-Hogg-Dubé (BHD) syndrome is a cancer disorder caused by a pathogenic FLCN mutation characterized by fibrofolliculomas, lung cysts, pneumothorax, benign renal cyst, and renal cell carcinoma (RCC). In this case we describe a patient with bilateral renal tumour and a positive familial history for pneumothorax and renal cancer. Based on this clinical presentation, the patient was suspected for BHD syndrome, which was confirmed after molecular testing. We discuss the importance of recognizing this autosomal dominant cancer disorder when a patient is presented at the urologist with a positive family history of chromophobe renal cell cancer or a positive familial history for renal cell cancer and pneumothorax. [ABSTRACT FROM AUTHOR]

Background: Birt-Hogg-Dubé (BHD) syndrome is an autosomal dominant condition caused by germline FLCN mutations, and characterised by fibrofolliculomas, pneumothorax and renal cancer. The renal cancer risk, cancer phenotype and pneumothorax risk of BHD have not yet been fully clarified. The main focus of this study was to assess the risk of renal cancer, the histological subtypes of renal tumours and the pneumothorax risk in BHD.Methods: In this study we present the clinical data of 115 FLCN mutation carriers from 35 BHD families.Results: Among 14 FLCN mutation carriers who developed renal cancer 7 were <50 years at onset and/or had multifocal/bilateral tumours. Five symptomatic patients developed metastatic disease. Two early-stage cases were diagnosed by surveillance. The majority of tumours showed characteristics of both eosinophilic variants of clear cell and chromophobe carcinoma. The estimated penetrance for renal cancer and pneumothorax was 16% (95% minimal confidence interval: 6-26%) and 29% (95% minimal confidence interval: 9-49%) at 70 years of age, respectively. The most frequent diagnosis in families without identified FLCN mutations was familial multiple discoid fibromas.Conclusion: We confirmed a high yield of FLCN mutations in clinically defined BHD families, we found a substantially increased lifetime risk of renal cancer of 16% for FLCN mutation carriers. The tumours were metastatic in 5 out of 14 patients and tumour histology was not specific for BHD. We found a pneumothorax risk of 29%. We discuss the implications of our findings for diagnosis and management of BHD. [ABSTRACT FROM AUTHOR]

Johannesma PC, van der Klift HM, van Grieken NCT, Troost D, te Riele H, Jacobs MAJM, Postma TJ, Heideman DAM, Tops CMJ, Wijnen JT, Menko FH. Childhood brain tumours due to germline bi-allelic mismatch repair gene mutations. Childhood brain tumours may be due to germline bi-allelic mismatch repair (MMR) gene mutations in MLH1, MSH2, MSH6 or PMS2. These mutations can also lead to colorectal neoplasia and haematological malignancies. Here, we review this syndrome and present siblings with early-onset rectal adenoma and papillary glioneural brain tumour, respectively, due to novel germline bi-allelic PMS2 mutations. Identification of MMR protein defects can lead to early diagnosis of this condition. In addition, assays for these defects may help to classify brain tumours for research protocols aimed at targeted therapies. [ABSTRACT FROM AUTHOR]

Under conditions of reduced tissue oxygenation, hypoxia-inducible factor (HIF) controls many processes, including angiogenesis and cellular metabolism, and also influences cell proliferation and survival decisions. HIF is centrally involved in tumour growth in inherited diseases that give rise to renal cell carcinoma (RCC), such as Von Hippel-Lindau syndrome and tuberous sclerosis complex. In this study, we examined whether HIF is involved in tumour formation of RCC in Birt-Hogg-Dubé syndrome. For this, we analysed a Birt-Hogg-Dubé patient-derived renal tumour cell line (UOK257) that is devoid of the Birt-Hogg-Dubé protein (BHD) and observed high levels of HIF activity. Knockdown of BHD expression also caused a threefold activation of HIF, which was not as a consequence of more HIF1α or HIF2α protein. Transcription of HIF target genes VEGF, BNIP3 and CCND1 was also increased. We found nuclear localization of HIF1α and increased expression of VEGF, BNIP3 and GLUT1 in a chromophobe carcinoma from a Birt-Hogg-Dubé patient. Our data also reveal that UOK257 cells have high lactate dehydrogenase, pyruvate kinase and 3-hydroxyacyl-CoA dehydrogenase activity. We observed increased expression of pyruvate dehydrogenase kinase 1 (a HIF gene target), which in turn leads to increased phosphorylation and inhibition of pyruvate dehydrogenase. Together with increased protein levels of GLUT1, our data reveal that UOK257 cells favour glycolytic rather than lipid metabolism (a cancer phenomenon termed the 'Warburg effect'). UOK257 cells also possessed a higher expression level of the L-lactate influx monocarboxylate transporter 1 and consequently utilized L-lactate as a metabolic fuel. As a result of their higher dependency on glycolysis, we were able to selectively inhibit the growth of these UOK257 cells by treatment with 2-deoxyglucose. This work suggests that targeting glycolytic metabolism may be used therapeutically to treat Birt-Hogg-Dubé-associated renal lesions. [ABSTRACT FROM AUTHOR]

Vos J, Oosterwijk JC, Gómez-García E, Menko FH, Jansen AM, Stoel RD, van Asperen CJ, Tibben A, Stiggelbout AM. Perceiving cancer-risks and heredity-likelihood in genetic-counseling: how counselees recall and interpret BRCA 1/2-test results. Previous studies on the counsellees' perception of DNA test results did not clarify whether counsellees were asked about their recollections or interpretations, and focused only on patients' own risks and not on the likelihood that cancer is heritable in the family. We tested differences and correlations of four perception aspects: recollections and interpretations of both cancer risks and heredity likelihood. In a retrospective study, women tested for BRCA1/2 on average, 5 years ago, completed questionnaires about their perception. Participants had received an unclassified variant ( n = 76), uninformative ( n = 76) or pathogenic mutation ( n = 51) result in BRCA1/2. Analyses included t-tests, correlations and structural equation modelling. The counsellees' perception showed to consist of four distinctive phenomena: recollections and interpretations of cancer risks and of heredity likelihood. This distinctiveness was suggested by significant differences between these perception variables. Moderate to strong correlations were found between these variables, suggesting that these differences between variables were consistent. The relationships between these variables were not influenced by actually communicated DNA test results, sociodemographics, medical and pedigree information, or framing of cancer risk questions. The largest differences between recollections and interpretations were found in the unclassified variant group and the smallest in uninformatives. Cancer risks and heredity likelihood correlated least in the pathogenic mutation group. Communication of ambiguous genetic information enlarged the differences. To understand the counsellees' perception of genetic counselling, researchers should study recollections and interpretations of cancer risks and heredity likelihood. Genetic counsellors should explicitly address the counsellees' recollections and interpretations, and be aware of possible inaccuracies. [ABSTRACT FROM AUTHOR]

Smit DL, Mensenkamp AR, Badeloe S, Breuning MH, Simon MEH, van Spaendonck KY, Aalfs CM, Post JG, Shanley S, Krapels IPC, Hoefsloot LH, van Moorselaar RJA, Starink TM, Bayley J-P, Frank J, van Steensel MAM, Menko FH. Hereditary leiomyomatosis and renal cell cancer in families referred for fumarate hydratase germline mutation analysis. Heterozygous fumarate hydratase ( FH) germline mutations cause hereditary leiomyomatosis and renal cell cancer (HLRCC), an autosomal dominant syndrome characterized by multiple cutaneous piloleiomyomas, uterine leiomyomas and papillary type 2 renal cancer. The main objective of our study was to evaluate clinical and genetic data from families suspected of HLRCC on a nationwide level. All families referred for FH mutation analysis in the Netherlands were assessed. We performed FH sequence analysis and multiplex ligation-dependent probe amplification. Families with similar FH mutations were examined for haplotype sharing. In 14 out of 33 families, we identified 11 different pathogenic FH germline mutations, including 4 novel mutations and 1 whole-gene deletion. Clinical data were available for 35 FH mutation carriers. Cutaneous leiomyomas were present in all FH mutation carriers older than 40 years of age. Eleven out of 21 female FH mutation carriers underwent surgical treatment for symptomatic uterine leiomyomas at an average of 35 years. Two FH mutation carriers had papillary type 2 renal cancer and Wilms' tumour, respectively. We evaluated the relevance of our findings for clinical practice and have proposed clinical diagnostic criteria, indications for FH mutation analysis and recommendations for management. [ABSTRACT FROM AUTHOR]

AIMS: Ductal carcinoma in situ (DCIS) is an established late precursor of sporadic invasive breast cancer and to a large extent parallels its invasive counterpart with respect to molecular changes and immunophenotype. Invasive breast cancers in germline BRCA1 and BRCA2 mutation carriers have a distinct "basal" and "luminal" immunophenotype, respectively, but the immunophenotype of their precursor lesions has hardly been studied, and this was the aim of this study. METHODS: DCIS lesions of 25 proven BRCA1 and 9 proven BRCA2 germline mutation carriers and their 22 and 6, respectively, accompanying invasive lesions were stained by immunohistochemistry for oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor (HER)2/neu, cytokeratin (CK)5/6, CK14, epidermal growth factor receptor (EGFR) and Ki67. RESULTS: DCIS lesions in BRCA1 mutation carriers were mostly of the basal molecular type with low ER/PR/HER2 expression, while they frequently expressed CK5/6, CK14 and EGFR, and were mostly grade 3 and highly proliferative. DCIS lesions in BRCA2 mutation carriers were mostly of luminal molecular type with frequent expression of ER/PR, and infrequent expression of CK5/6, CK14 and EGFR, and they were mostly grade 3 and showed low proliferation. In BRCA1 and BRCA2 mutation carriers there was a high concordance between DCIS lesions and their concomitant invasive counterpart with regard to expression of individual markers as well as "molecular" subtype. CONCLUSIONS: Although the number of cases studied was low, DCIS lesions in BRCA1 and BRCA2 mutations carriers are usually of the basal and luminal molecular type, respectively, similar to their accompanying invasive cancers, thereby providing evidence that DCIS is a direct precursor lesion in these hereditary predisposed patients. This also suggests that crucial carcinogenetic events leading to these phenotypes in hereditary predisposed patients occur before the stage of invasion. [ABSTRACT FROM AUTHOR]

Infantile juvenile polyposis is a rare disease with severe gastrointestinal symptoms and a grave clinical course. Recently, 10q23 microdeletions involving the PTEN and BMPR1A genes were found in four patients with infantile juvenile polyposis. It was hypothesized that a combined and synergistic effect of the deletion of both genes would explain the condition. Subsequently, however, a patient with a larger 10q23 deletion including the same genes but with a mild clinical phenotype was identified. Here, we present four additional patients with 10q23 microdeletions involving the PTEN and BMPR1A genes. The sizes of the deletions were analyzed using single nucleotide polymorphism array analysis. All patients had macrocephaly, dysmorphic features, retardation and congenital abnormalities. One patient developed colorectal cancer. However, only one case had disease onset before 2 years of age and severe symptoms requiring colectomy. No clear correlation was found between ages at onset or severity of gastrointestinal symptoms and the sizes of the deletions. We conclude that patients with 10q23 microdeletions involving the PTEN and BMPR1A genes have variable clinical phenotypes, which cannot be explained merely by the deletion sizes. The phenotypes are not restricted to severe infantile juvenile polyposis but include childhood-onset cases with macrocephaly, retardation, mild gastrointestinal symptoms and possibly early-onset colorectal cancer. [ABSTRACT FROM AUTHOR]

LKB1/STK11 germline inactivations are identified in the majority (66–94%) of Peutz–Jeghers syndrome (PJS) patients. Therefore, defects in other genes or so far unidentified ways of LKB1 inactivation may cause PJS. The genes encoding the MARK proteins, homologues of the Par1 polarity protein that associates with Par4/Lkb1, were analyzed in this study because of their link to LKB1 and cell polarity. The genetic defect underlying PJS was determined through analysis of both LKB1 and all four MARK genes. LKB1 point mutations and small deletions were identified in 18 of 23 PJS families using direct sequencing and multiplex ligation-dependent probe amplification analysis identified exon deletions in 3 of 23 families. In total, 91% of the studied families showed LKB1 inactivation. Furthermore, a MARK1, MARK2, MARK3 and MARK4 mutation analysis and an MARK4 quantitative multiplex polymerase chain reaction analysis to identify exon deletions on another eight PJS families without identified LKB1 germline mutation did not identify mutations in the MARK genes. LKB1 defects are the major cause of PJS and genes of the MARK family do not represent alternative PJS genes. Other mechanisms of inactivation of LKB1 may cause PJS in the remaining families. [ABSTRACT FROM AUTHOR]

Background: Small bowel cancer (SBC) is one of the tumours associated with Lynch syndrome (LS). To advise on screening for this tumour it is paramount to be informed about the lifetime risk. The aim of this study was to calculate the lifetime risk of SBC in LS and to identify possible risk factors. Methods: Clinical and pathological data were collected on 1496 proven or putative carriers of a mismatch repair gene mutation from 189 families. Kaplan-Meier survival analysis was used to calculate the lifetime risk and to assess potential risk factors. Results: 28 (1.9%) of the 1496 (putative) mutation carriers were identified with SBC. The median age at diagnosis was 52 years (range 23-69 years). The lifetime risk of developing SBC was 4.2%. There was no difference in risk between males and females (log rank: p = 0.2470), or between MLH1 and MSH2 mutation carriers (log rank: p = 0.2754). SBC was not observed in MSH6 mutation carriers (n = 203). The previous occurrence of colorectal cancer and a family history of SBC did not increase the risk significantly. Conclusions: Approximately, one out of 25 mutation carriers will develop SBC during life. No specific risk factors were identified. The risk appeared to be too low to advise screening by means of an invasive burdensome procedure like double balloon enteroscopy. However, screening by a non-invasive procedure (videocapsule endoscopy) might be considered if future studies will show its cost effectiveness. In patients with unexplained abdominal complaints and/or unexplained iron deficiency anaemia SBC should be considered. [ABSTRACT FROM AUTHOR]

Background: About 5% of all breast cancer cases are attributable to germline mutations in BRCA1 or BRCA2 genes. BRCA mutations in suspected carriers, however, may be missed, which hampers genetic counselling. Materials and methods: Different clinicopathological features were compared between 22 breast cancers from carriers of proved BRCA1 mutations and 604 cancers from sporadic controls. In addition, 5 BRCA2- related breast cancers and 66 breast cancers of untested patients at intermediate risk and 19 breast cancers of untested patients at high risk of hereditary disease on the basis of family history were evaluated. Results: A ‘probably sporadic’ class (age ⩾54 years and epidermal growth factor receptor (EGFR) negative; 68% of cases) with a 0% chance of BRCA1-related breast cancer containing 79% of the sporadic cases was yielded by using a decision tree with age, Ki67 and EGFR. A 75% chance of BRCA1-related breast cancer was shown by the ‘probably BRCA1-related’ class (age <54 years and Ki67 ⩾25%; 8% of cases) with 82% of the BRCA1-related cases but only 1 .4% of the sporadic cases. Most cases at intermediate or high risk of hereditary disease on the basis of family history could be classified with high probability as either probably BRCA1 related or probably sporadic. Conclusion: Breast carcinomas can be classified with a high level of certainty as sporadic or related to BRCA1 germline mutations by using a decision tree with age, Ki67 and EGFR. This can be clinically useful in mutation analysis in families with a borderline risk of hereditary disease. [ABSTRACT FROM AUTHOR]

Background/Aims: LKB1 is a tumour suppressor gene that is associated with Peutz-Jeghers syndrome (PJS), a rare autosomal dominant cancer predisposition syndrome. However, germline mutations in the LKB1 gene are found in only about 60% of patients with PJS, suggesting the existence of a second PJS gene. The STRAD gene, encoding an LKB1 interacting protein that activates LKB1, which subsequently leads to polarisation of cells, is an interesting candidate for a second PJS gene and a potential tumour suppressor gene in sporadic carcinomas. Methods: The involvement of STRAD in 42 PJS associated tumours (sporadic lung, colon, gastric, and ovarian adenocarcinomas) was studied using loss of heterozygosity (LOH) analysis of eight microsatellite markers on chromosome 17, including TP53, BRCA1, and STRAD markers. Results: Loss of the marker near the STRAD locus was seen in 13 of 29 informative cases, including all gastric adenocarcinomas. Specific LOH of the STRAD marker was found in four of 29 informative cases. For these patients all exons and exon-intron boundaries of the STR4D gene were sequenced, but no somatic mutations were identified. Furthermore, no germline STRAD mutations were found in 10 patients with PJS and family members without LKB1 germline mutation. Conclusions: Despite the frequent occurrence of LOH in the STRAD region, these results indicate that inactivation of the STRAD gene is not essential in the sporadic adenocarcinomas studied, although it is possible that STRAD may be inactivated in different ways. In addition, no evidence was found for the hypothesis that STRAD is a second PJS susceptibility gene. [ABSTRACT FROM AUTHOR]

Background: In BRCA2 mutation carriers, increased risks have been reported for several cancer sites besides breast and ovary. As most of the families included in earlier reports were selected on the basis of multiple breast/ovarian cancer cases, it is possible that risk estimates may differ in mutation carriers with a less striking family history. Methods: In the Netherlands, 139 BRCA2 families with 66 different pathogenic mutations were included in a nationwide study. To avoid testing bias, we chose not to estimate risk in typed carriers, but rather in male and female family members with a 50% prior probability of being a carrier (n=1811). The relative risk (RR) for each cancer site with the exception of breast and ovarian cancer was determined by comparing observed numbers with those expected, based on Dutch cancer incidence rates. Results: We observed an excess risk for four cancer sites: pancreas (RR 5.9; 95% confidence interval (CI) 3.2 to 10.0), prostate (2.5; 1.6 to 3.8), bone (14.4; 2.9 to 42.1) and pharynx (7.3; 2.0 to 18.6). A small increase was observed far cancer of the digestive tract (1.5; 1.1 to 1.9). Histological verification was available for 46% of the tumours. Nearly all increased risks reached statistical significance for men only. Cancer risks tended to be higher far people before the age of 65 years. Moreover, families with mutations outside the previously defined ovarian cancer cluster region tended to have a higher cancer risk. Conclusions: We found that BRCA2 carriers are at increased risk far cancers of the prostate and pancreas, and possibly bone and pharynx. Larger databases with extended fallow up are needed to provide insight into mutation specific risks of selected carriers in BRCA2 families. [ABSTRACT FROM AUTHOR]

Background: In view of the high risk of developing a new primary colorectal carcinoma (CRC), subtotal colectomy rather than segmental resection or hemicolectomy is the preferred treatment in hereditary non- polyposis colorectal cancer (HNPCC) patients. Subtotal colectomy however implies a substantial decrease in quality of life. To date, colonoscopic surveillance has been shown to reduce CRC occurrence. Aims: To compare the potential health effects in terms of life expectancy (LE) for patients undergoing subtotal colectomy or hemicolectomy for CRC. Methods: A decision analysis (Markov) model was created. Information on the 10 year risk of CRC after subtotal colectomy (4%) and hemicolectomy (16%) and stages of CRCs detected within a two year surveillance interval (32% Dukes' A, 54% Dukes' B, and 14% Dukes' C) were derived from two cohort studies. Five year survival rates used for the different Dukes stages (A, B, and C) were 98%, 80%, and 60%, respectively. Remaining LE values were calculated for hypothetical cohorts with an age at CRC diagnosis of 27, 47, and 67 years, respectively. Remaining LE values were also calculated for patients with CRC of Dukes' stage A. Results: The overall LE gain of subtotal colectomy compared with hemicolectomy at ages 27, 47, and 67 was 2.3, 1, and 0.3 years, respectively. Specifically for Dukes' stage A, this would be 3.4, 1 .5, and 0.4 years. Conclusions: Unless surveillance results improve, subtotal colectomy still seems the preferred treatment for CRC in HNPCC in view of the difference in LE. For older patients, hemicolectomy may be an option as there is no appreciable difference in LE. [ABSTRACT FROM AUTHOR]

Aims: To investigate the occurrence of preinvasive neoplastic lesions in ovarian surface epithelium and ovarian inclusion cyst epithelium of women with a hereditary predisposition to the development of female adnexal (ovarian and fallopian tube) carcinoma and to assess the expression of differentiation and proliferation related proteins within putative sites of origin of serous ovarian carcinoma, the ovarian surface epithelium and ovarian inclusion cyst epithelium. Methods: Twenty-one ovaries, prophylactically removed from 11 women predisposed to the development of female adnexal cancer (cases) were compared with 22 ovaries from 11 women without such predisposition (controls). Archival histological specimens were screened for hyperplastic and dysplastic epithelial lesions. In both the ovarian surface and inclusion cyst epithelia, the percentage of cells was determined that stained positively for Ki67, p21, p27, p53, cyclin A, cyclin D1, bcl-2 and the presence of HER-2/neu, oestrogen (ER-α) and progesterone receptors (PR). Results: No preinvasive neoplastic lesions were detected. However, hyperplastic areas were found in three cases and in four controls (NS). ER-α (P = 0.013), PR (P < 0.001), bcl-2 (P = 0.008), p21 (P = 0.046) and p27 (P = 0.008) were expressed in a significantly higher percentage of cells in inclusion cyst epithelium than in ovarian surface epithelium (both groups). The latter showed higher bcl-2 expression in cases (P = 0.05) compared with controls. The inclusion cyst epithelium of cases showed higher expression of bcl-2 (P = 0.006) and PR (P = 0.039) compared with controls. Proliferation was low in both cases and controls as reflected by low Ki67 expression. Over-expression of p53, cyclin D1 and HER-2/neu was not detected. Conclusions: Premalignant changes are not a common feature of ovaries removed prophylactically from women predisposed to the development of female adnexal carcinoma. Increased expression of p21, p27, and... [ABSTRACT FROM AUTHOR]

Hereditary non-polyposis colorectal cancer is an autosomal dominant condition due to germline mutations in DNA-mismatch-repair genes, in particular MLH1, MSH2 and MSH6. Here we describe the application of a novel technique for the detection of genomic deletions in MLH1 and MSH2. This method, called multiplex ligation-dependent probe amplification, is a quantitative multiplex PCR approach to determine the relative copy number of each MLH1 and MSH2 exon. Mutation screening of genes was performed in 126 colorectal cancer families selected on the basis of clinical criteria and in addition, for a subset of families, the presence of microsatellite instability (MSI-high) in tumours. Thirty-eight germline mutations were detected in 37 (29.4%) of these kindreds, 31 of which have a predicted pathogenic effect. Among families with MSI-high tumours 65.7% harboured germline gene defects. Genomic deletions accounted for 54.8% of the pathogenic mutations. A complete deletion of the MLH1 gene was detected in two families. The multiplex ligation-dependent probe amplification approach is a rapid method for the detection of genomic deletions in MLH1 and MSH2. In addition, it reveals alterations that might escape detection using conventional diagnostic techniques. Multiplex ligation-dependent probe amplification might be considered as an early step in the molecular diagnosis of hereditary non-polyposis colorectal cancer. [ABSTRACT FROM AUTHOR]

In two sibs antenatal ultrasonography revealed identical intracranial calcification, ventricular widening and microcephaly. The first pregnancy was artificially terminated at 19 weeks. Post-mortem examination of the brain revealed destructive calcification and extracerebral neuronal heterotopia. The second sib went to term but died 48 h after birth from irreversible lactic acidosis. Autopsy showed extensive encephalopathy with cavitation and calcification in the cerebral hemispheres, polymicrogyria, multiple neuronal heterotopia, partial callosal dysgenesis, and severe Leigh syndrome, together forming a continuum of early and late brain disruption. Mitochondrial respiratory chain abnormalities, mainly affecting complexes I and IV, and deficiency of pyruvate dehydrogenase complex were detected in skeletal muscle and in liver. A normal functioning of the respiratory chain was found in the fibroblasts. Analysis of mtDNA from muscle, liver and blood revealed normal amounts of intact mtDNA without any of the known point mutations associated with MELAS, MERRF or Leigh syndromes. The early fetal disruption and necrotic changes in the brains of sibs indicate a specific genetically determined disorder which affects neuronal migration, a finding not previously associated with respiratory chain disorders. The present disorder may mimic antenatal congenital infectious encephalopathy because of the combined finding of microcephaly and destructive intracerebral calcification. [ABSTRACT FROM AUTHOR]

The age at onset of non-polyposis colorectal cancer (CRC) was investigated in 49 families with at least three relatives affected in two successive generations. Forty one of these families satisfy the accepted minimum criteria for hereditary non-polyposis CRC. The remaining eight families were distinguished by a late age of disease onset and, hence, could not be included in the group. The condition in these latter families has been designated provisionally, as late onset familial CRC. The hereditary non-polyposis CRC families include 194 patients, 110 men and 84 women (mean age at diagnosis: 44 years; range: 16-74 years). Ninety two per cent of the patients were diagnosed by age 60. Colorectal cancer was diagnosed at progressively earlier ages in successive generations (p < 0.0005). The late onset CRC families comprised 30 patients, 20 men and 10 women (mean age at diagnosis: 62 years; range: 51-77 years). Fifty eight per cent of the CRCs in the patients belonging to the hereditary non-polyposis CRC families were located in the right colon compared with 13% in the late onset familial CRC group (p < 0.001). Multiple CRCs were found in 23% of the cases in the former but in only 3% in the latter families (p < 0.05). Adenomas associated with CRC were reported in 14.5% of the cases in the hereditary non-polyposis CRC families and in 30% of the cases in the late onset familial CRC group (p = NS). Extracolonic cancers, frequently encountered in hereditary non-polyposis CRC, were not found in the late onset CRC families. These findings indicate that there is a distinct clinical entity of non-polyposis CRC in which colorectal cancer develops at a more advanced age than in hereditary non-polyposis CRC. Future molecular genetic studies should confirm this hypothesis. In the meantime, recognition of these late onset familial CRC families, which will rest on clinical observations, is important because of the implications for the screening protocol. [ABSTRACT FROM PUBLISHER]

Background: Peutz-Jeghers syndrome (PJS) is caused by germline STK11 mutations and characterised by gastrointestinal polyposis. Although small bowel intussusception is a recognised complication of PJS, risk varies between patients. Objective: To analyse the time to onset of intussusception in a large series of PJS probands. Methods: STK11 mutation status was evaluated in 225 PJS probands and medical histories of the patients reviewed. Results: 135 (60%) of the probands possessed a germline STK11 mutation; 109 (48%) probands had a history of intussusception at a median age of 15.0 years but with wide variability (range 3.7 to 45.4 years). Median time to onset of intussusception was not significantly different between those with identified mutations and those with no mutation detected, at 14.7 years and 16.4 years, respectively (log-rank test of difference, x2 = 0.58, with 1df; p = 0.45). Similarly no differences were observed between patient groups on the basis of the type or site of STK11 mutation. Conclusions: The risk of intussusception in PJS is not influenced by STK11 mutation status. [ABSTRACT FROM AUTHOR]

The article discusses a study that analyzes a novel GATA2 mutation in a large family using Sanger sequencing of peripheral blood DNA. It reveals two novel mutations located within exon two in which one was caused by the deletion of a single pair resulting in a frameshift at amino acid 28 (G28fs) and second was a missence mutation (H26P). It indicates that the large family of highly illustrative for the clinical variability and difficulty in predicting outcome in GATA2 mutation carriership.