Two-photon induced polarization spectroscopy of xenon 7p[1/2]0

A novel experimental setup for two-photon induced polarization spectroscopy of xenon using a single dye laser is demonstrated. The experimental setup for probing this two-photon xenon transition using this technique has been developed in the High Enthalpy Flow Diagnostics Group of the Institute of Space Systems. The characterization of the setup is achieved through a polarization lineshape modelling approach accounting for absorption, dispersion, and imperfections in the alignment of the analyzing polarizer for asymmetrical polarization profiles. It is demonstrated that the lineshape modelling approach yields consistent results for measurements with pronounced asymmetrical lineshape properties as well as for those with symmetrical lineshapes. For the first time, data on pressure broadening and pressure dependent redshift of the absorption center wavelength of xenon 7p[1/2]₀ is presented. The results show a pressure broadening of 1.475 pm/bar full width at half maximum and a redshift of 0.8425 pm/bar.

Somatic copy number changes in DPYD are associated with lower risk of recurrence in triple-negative breast cancers

BACKGROUND

Genomic rearrangements at the fragile site FRA1E may disrupt the dihydropyrimidine dehydrogenase gene (DPYD) which is involved in 5-fluorouracil (5-FU) catabolism. In triple-negative breast cancer (TNBC), a subtype of breast cancer frequently deficient in DNA repair, we have investigated the susceptibility to acquire copy number variations (CNVs) in DPYD and evaluated their impact on standard adjuvant treatment.

METHODS

DPYD CNVs were analysed in 106 TNBC tumour specimens using multiplex ligation-dependent probe amplification (MLPA) analysis. Dihydropyrimidine dehydrogenase (DPD) expression was determined by immunohistochemistry in 146 tumour tissues.

RESULTS

In TNBC, we detected 43 (41%) tumour specimens with genomic deletions and/or duplications within DPYD which were associated with higher histological grade (P=0.006) and with rearrangements in the DNA repair gene BRCA1 (P=0.007). Immunohistochemical analysis revealed low, moderate and high DPD expression in 64%, 29% and 7% of all TNBCs, and in 40%, 53% and 7% of TNBCs with DPYD CNVs, respectively. Irrespective of DPD protein levels, the presence of CNVs was significantly related to longer time to progression in patients who had received 5-FU- and/or anthracycline-based polychemotherapy (hazard ratio=0.26 (95% CI: 0.07-0.91), log-rank P=0.023; adjusted for tumour stage: P=0.037).

CONCLUSION

Genomic rearrangements in DPYD, rather than aberrant DPD protein levels, reflect a distinct tumour profile associated with prolonged time to progression upon first-line chemotherapy in TNBC.

Klinik und Genetik des familiären Brust- und Eierstockkrebses

Während mit der Entdeckung der Hochrisikogene „breast cancer 1“ (BRCA1) und „breast cancer 2“ (BRCA2) in den Jahren 1994/1995 die Erforschung des hereditären Mamma- und Ovarialkarzinoms zunächst beendet schien, belegen neuere Ergebnisse, dass das hereditäre Mamma- und Ovarialkarzinom eine extreme genetische Heterogenität aufweist. Die genetisch definierten Subtypen zeigen außerdem eine unterschiedliche phänotypische Ausprägung hinsichtlich der histopathologischen Charakteristika, des Krankheitsverlaufs und des Therapieansprechens. Dies erfordert eine Einbettung der Gendiagnostik in ein strukturiertes und standardisiertes Betreuungskonzept, das es erlaubt prospektive Daten zur Tumorinzidenz und zum Verlauf zu erfassen sowie in prospektiven Studien die Wertigkeit der verschiedenen diagnostischen, präventiven und neuen therapeutischen Optionen zu validieren. Das deutsche Konsortium widmet sich dieser Aufgabenstellung, um den betreffenden Familien effiziente Präventions- und Interventionsstrategien anbieten zu können. Dabei kommt der Zusammenarbeit mit der Selbsthilfe (http://www.BRCA-Netzwerk.de) mittlerweile eine große Bedeutung zu, die uns immer wieder vor Augen hält, wie wichtig es ist, den in diesem Artikel aufgeworfenen Fragestellungen nachzugehen.

Association of PHB 1630 C>T and MTHFR 677 C>T polymorphisms with breast and ovarian cancer risk in BRCA1/2 mutation carriers: results from a multicenter study

BACKGROUND

The variable penetrance of breast cancer in BRCA1/2 mutation carriers suggests that other genetic or environmental factors modify breast cancer risk. Two genes of special interest are prohibitin (PHB) and methylene-tetrahydrofolate reductase (MTHFR), both of which are important either directly or indirectly in maintaining genomic integrity.

METHODS

To evaluate the potential role of genetic variants within PHB and MTHFR in breast and ovarian cancer risk, 4102 BRCA1 and 2093 BRCA2 mutation carriers, and 6211 BRCA1 and 2902 BRCA2 carriers from the Consortium of Investigators of Modifiers of BRCA1 and BRCA2 (CIMBA) were genotyped for the PHB 1630 C>T (rs6917) polymorphism and the MTHFR 677 C>T (rs1801133) polymorphism, respectively.

RESULTS

There was no evidence of association between the PHB 1630 C>T and MTHFR 677 C>T polymorphisms with either disease for BRCA1 or BRCA2 mutation carriers when breast and ovarian cancer associations were evaluated separately. Analysis that evaluated associations for breast and ovarian cancer simultaneously showed some evidence that BRCA1 mutation carriers who had the rare homozygote genotype (TT) of the PHB 1630 C>T polymorphism were at increased risk of both breast and ovarian cancer (HR 1.50, 95%CI 1.10-2.04 and HR 2.16, 95%CI 1.24-3.76, respectively). However, there was no evidence of association under a multiplicative model for the effect of each minor allele.

CONCLUSION

The PHB 1630TT genotype may modify breast and ovarian cancer risks in BRCA1 mutation carriers. This association need to be evaluated in larger series of BRCA1 mutation carriers.

Prevalence Rates of Pathogenic Mutations in the BRCA1 and BRCA2 Genes in Families with Different Disease Histories: Results from the German Consortium for Hereditary Breast and Ovarian Cancer

Introduction: In the German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC), a large number of families with different histories of breast and ovarian cancers was screened for pathogenic mutations in the tumor-suppressor genes BRCA1/2. We here aimed to analyse the prevalence rates of pathogenic mutations for various familial disease histories.Methods: From 1997-2009 more than 6,000 families were screened for pathogenic mutations in BRCA1/2. Mutation analysis was performed by DHPLC (denaturing high-performance liquid chromatography) pre-screening, direct sequencing of suspect fragments and MLPA (multiplex ligation-dependant probe amplification) in at least one index case of these families. Complete pedigree information over three generations was used for the analysis. All lineages within a pedigree were traced and checked for the presence of several predefined disease histories.Results: Detailed mutation prevalence rates have been determined for a variety of familial risk situations. The highest mutation prevalence rate (78%, 95%CI 67-87%) was seen in families with at least two relatives affected by pre-menopausal breast cancer and at least two affected by ovarian cancer at any age. Importantly, the presence of a single woman affected by breast and ovarian cancer or bilateral breast cancer with first breast cancer under the age of 41 was associated with a BRCA1/2 mutation prevalence of 53% (95%CI 48-59%) and 34% (95%CI 23-47%) respectively. Interestingly, low mutation prevalence rates of <10% were found in families with only one case of male breast cancer (9%, 95%CI 4-19%), and in families with three or more cases of postmenopausal breast cancer (7%, 95%CI 4-14%), the former being only BRCA2 mutations. Overall, the mutation prevalence was 27% (95% CI 26-29%) in the whole cohort.Conclusion: We provide comprehensive estimates for BRCA1/2 mutation prevalence rates that are based on a large number of families with comprehensive pedigree information. Such estimates can be used to develop cost effective screening strategies for public health care providers.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4073.

Evaluation of a candidate breast cancer associated SNP in ERCC4 as a risk modifier in BRCA1 and BRCA2 mutation carriers. Results from the Consortium of Investigators of Modifiers of BRCA1/BRCA2 (CIMBA)

Background:

In this study we aimed to evaluate the role of a SNP in intron 1 of the ERCC4 gene (rs744154), previously reported to be associated with a reduced risk of breast cancer in the general population, as a breast cancer risk modifier in BRCA1 and BRCA2 mutation carriers.

Methods:

We have genotyped rs744154 in 9408 BRCA1 and 5632 BRCA2 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and assessed its association with breast cancer risk using a retrospective weighted cohort approach.

Results:

We found no evidence of association with breast cancer risk for BRCA1 (per-allele HR: 0.98, 95% CI: 0.93–1.04, P=0.5) or BRCA2 (per-allele HR: 0.97, 95% CI: 0.89–1.06, P=0.5) mutation carriers.

Conclusion:

This SNP is not a significant modifier of breast cancer risk for mutation carriers, though weak associations cannot be ruled out.

The TP53 Arg72Pro and MDM2 309G>T polymorphisms are not associated with breast cancer risk in BRCA1 and BRCA2 mutation carriers

Background:

The TP53 pathway, in which TP53 and its negative regulator MDM2 are the central elements, has an important role in carcinogenesis, particularly in BRCA1- and BRCA2-mediated carcinogenesis. A single nucleotide polymorphism (SNP) in the promoter region of MDM2 (309T>G, rs2279744) and a coding SNP of TP53 (Arg72Pro, rs1042522) have been shown to be of functional significance.

Methods:

To investigate whether these SNPs modify breast cancer risk for BRCA1 and BRCA2 mutation carriers, we pooled genotype data on the TP53 Arg72Pro SNP in 7011 mutation carriers and on the MDM2 309T>G SNP in 2222 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Data were analysed using a Cox proportional hazards model within a retrospective likelihood framework.

Results:

No association was found between these SNPs and breast cancer risk for BRCA1 (TP53: per-allele hazard ratio (HR)=1.01, 95% confidence interval (CI): 0.93–1.10, P_trend=0.77; MDM2: HR=0.96, 95%CI: 0.84–1.09, P_trend=0.54) or for BRCA2 mutation carriers (TP53: HR=0.99, 95%CI: 0.87–1.12, P_trend=0.83; MDM2: HR=0.98, 95%CI: 0.80–1.21, P_trend=0.88). We also evaluated the potential combined effects of both SNPs on breast cancer risk, however, none of their combined genotypes showed any evidence of association.

Conclusion:

There was no evidence that TP53 Arg72Pro or MDM2 309T>G, either singly or in combination, influence breast cancer risk in BRCA1 or BRCA2 mutation carriers.

ARDS as presenting symptom in an infant with CD40L deficiency (Hyper-IgM syndrome Type 1)

We report on a 4 month old male infant with respiratory syncytial virus (RSV) infection leading to acute respiratory distress syndrome (ARDS). A diagnostic algorithm including extended infectiological and immunological work-up revealed absence of CD40-ligand. ARDS was treated successfully with a complex respiratory therapy plus intravenous immunoglobulin substitution. Molecular analysis detected mutations in the CD40L gene (Hyper-IgM syndrome Type 1). The case underlines the importance of an extended diagnostic work-up in an uncommonly severe course of respiratory infection in early infancy.

Counseling and care: A Breast Cancer Awareness Training to improve participation and adherence to screening recommendations in women with a family history of breast cancer

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Background: BRCA1 or BRCA2 mutation carriers are at an increased lifetime risk to develop breast and ovarian cancer. In a substantial number of families with affected members the known susceptibility genes cannot be identified. According to the recommendations of the German Consortium for Hereditary Breast and Ovarian Cancer, women with a hereditary predisposition for breast cancer should participate at an intensified surveillance program (ISP) including genetic counseling, risk estimation, BSE, CBE, BreastUS, MX, and MRI. Nonadherence might be influenced by cancer worryness, anxiety, health beliefs, and a lack of information about screening benefits.The aim of this investigation was to evaluate the impact of an indivualized Breast Cancer Awareness Training to improve the participation and adherence towards an ISP. Methods: Since 2005, an at-risk sample of 46 non-participating women (mean age 29 y; range 19–43 y) got an intensive breast cancer awareness training, including structured BSE, specific information about regular follow-up, screening advice, and radiological diagnostic procedures. To establish invidualized counseling and training particular needs (e.g., reasons for non-adherence, health beliefs and behaviours), risk perception, anxiety, and sociodemographic factors were evaluated by interviews and self-report questionnaires. The control group consisted of 38 participants of the ISP. Results: Breast cancer worry, anxiety, and lack of information about the benefits of screening programs were the main reasons for non-adherence. Within 3 months after the base counseling participation rates in MX (>30J), BUS, MRI, and CBE reached 98%. The numbers remain consistent in a 2-year follow up. 80% of participants practice BSE monthly, and 46% reported changes in lifestyle regarding nutrition, obesity, and health beliefs. Conclusions: Our approach emphasizes importance of self confidence and awareness for participation at the ISP for women at high breast cancer risk. Individualized counseling, BSE, re-evaluation, and reinforcement sessions are correlated with changes in health beliefs and behaviours for enhancing participation and adherence in women with a family history of breast cancer.

No significant financial relationships to disclose.

An evaluation of the polymorphisms Ins16bp and Arg72Pro in p53 as breast cancer risk modifiers in BRCA1 and BRCA2 mutation carriers

The close functional relationship between p53 and the breast cancer susceptibility genes BRCA1 and BRCA2 has promoted the investigation of various polymorphisms in the p53 gene as possible risk modifiers in BRCA1/2 mutation carriers. Specifically, two polymorphisms in p53, c.97-147ins16bp and p.Arg72Pro have been analysed as putative breast cancer susceptibility variants, and it has been recently reported that a p53 haplotype combining the absence of the 16-bp insertion and the presence of proline at codon 72 (No Ins-72Pro) was associated with an earlier age at the onset of the first primary tumour in BRCA2 mutation carriers in the Spanish population. In this study, we have evaluated this association in a series of 2932 BRCA1/2 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1 and BRCA2.

Classification of Non-Bacterial Osteitis: Retrospective study of clinical, immunological and genetic aspects in 89 patients

OBJECTIVE

To define non-bacterial osteitis (NBO) as a clinical entity possibly associated with autoimmune manifestations. Patients with sterile osteitis were analysed to develop diagnostic criteria.

METHODS

A total of 89 patients with non-bacterial inflammatory bone lesions were observed for a median of 49 months. History, diagnostic imaging, laboratory and histological data were obtained. Mutation analysis in the genes PSTPIP1 and PSTPIP2 was performed.

RESULTS

Patients had an onset of disease at a median age of 10 yrs [interquartile range (IQR) 7.5-12] and suffered a median period of 21 (IQR 9-52) months with a median of three foci per patient. Twenty percent of all the patients demonstrated associated autoimmune disorders, particularly of the skin and bowel. The majority of bone lesions were located in the vertebrae and metaphyses. Slight-to-moderate elevation of inflammation values were found in all the patients and antinuclear antibodies were elevated in 30%. Non-steroidal anti-inflammatory drugs (NSAIDs) were effective in 85% of the patients. HLA-B27 and Human Leukocyte Antigen-DR (HLA-DR)-classification did not differ from the general population. Autoimmune diseases in 40% of all the families, multiply affected family members, linkage to 18q21 and mouse models strongly indicate a genetic basis for NBO. We observed three different courses of disease regarding the duration of complaints, rate of complications and associated autoimmune manifestations leading to a new classification of NBO.

CONCLUSIONS

Clinical analysis of our cohort leads us to define NBO as a distinct disease entity with three clinical presentations: acute NBO, chronic recurrent multifocal osteomyelitis or persistent chronic NBO. Diagnostic criteria were proposed to differentiate NBO from diseases with similar clinical presentation.

Golabi-Ito-Hall syndrome results from a missense mutation in the WW domain of the PQBP1 gene

BACKGROUND

Golabi, Ito, and Hall reported a family with X linked mental retardation (XLMR), microcephaly, postnatal growth deficiency, and other anomalies, including atrial septal defect, in 1984.

METHODS

This family was restudied as part of our ongoing study of XLMR, but significant linkage to X chromosome markers could not be found. Extreme short stature and microcephaly as well as other new clinical findings were observed. Mutations in the polyglutamine tract binding protein 1 gene (PQBP1) have recently been reported in four XLMR disorders (Renpenning, Hamel cerebro-palato-cardiac, Sutherland-Haan, and Porteous syndromes) as well as in several other families. The clinical similarity of our family to these patients with mutations in PQBP1, particularly the presence of microcephaly, short stature, and atrial septal defect, prompted examination of this gene.

RESULTS

A missense mutation in PQBP1 was identified which changed the conserved tyrosine residue in the WW domain at position 65 to a cysteine (p.Y65C).

CONCLUSIONS

This is the first missense mutation identified in PQBP1 and the first mutation in the WW domain of the gene. The WW domain has been shown to play an important role in the regulation of transcription by interacting with the PPxY motif found in transcription factors. The p.Y65C mutation may affect the proper functioning of the PQBP1 protein as a transcriptional co-activator.

Strong evidence that the common variant S384F in BRCA2 has no pathogenic relevance in hereditary breast cancer

Introduction

Unclassified variants (UVs) of unknown clinical significance are frequently detected in the BRCA2 gene. In this study, we have investigated the potential pathogenic relevance of the recurrent UV S384F (BRCA2, exon 10).

Methods

For co-segregation, four women from a large kindred (BN326) suffering from breast cancer were analysed. Moreover, paraffin-embedded tumours from two patients were analysed for loss of heterozygosity. Co-occurrence of the variant with a deleterious mutation was further determined in a large data set of 43,029 index cases. Nature and position of the UV and conservation among species were evaluated.

Results

We identified the unclassified variant S384F in three of the four breast cancer patients (the three were diagnosed at 41, 43 and 57 years of age). One woman with bilateral breast cancer (diagnosed at ages 32 and 50) did not carry the variant. Both tumours were heterozygous for the S384F variant, so loss of the wild-type allele could be excluded. Ser384 is not located in a region of functional importance and cross-species sequence comparison revealed incomplete conservation in the human, dog, rodent and chicken BRCA2 homologues. Overall, the variant was detected in 116 patients, five of which co-occurred with different deleterious mutations. The combined likelihood ratio of co-occurrence, co-segregation and loss of heterozygosity revealed a value of 1.4 × 10^-8 in favour of neutrality of the variant.

Conclusion

Our data provide conclusive evidence that the S384F variant is not a disease causing mutation.

A splice site mutation in the methyltransferase gene FTSJ1 in Xp11.23 is associated with non-syndromic mental retardation in a large Belgian family (MRX9)

Mental retardation is the most frequent cause of serious handicap in children and young adults. The underlying causes of this heterogeneous condition are both acquired and genetically based. A recently performed refinement of the linkage interval in a large Belgian family with mild to severe non-syndromic X linked mental retardation, classified as MRX9, revealed a candidate region of 11.3 Mb between markers DXS228 and DXS1204 on the short arm of the X chromosome. In order to identify the underlying disease gene in the MRX9 family, we established a gene catalogue for the candidate region and performed comprehensive mutation analysis by direct sequencing. A human homologue of the bacterial 23S rRNA methyltransferase Fstj, the FTSJ1 gene, is located within this region and displayed a sequence alteration in the conserved acceptor splice site of intron 3 (IVS3-2A>G) in all tested patients and carrier females of this family. In contrast, it was absent in all unaffected male family members tested. The mutation results in skipping of exon 4 and introduces a premature stop codon in exon 5, probably leading to a severely truncated protein. Our finding indicates that a protein, possibly associated with ribosomal stability, can be linked to X linked mental retardation (XLMR).

Persistent hypogammaglobulinemia following mononucleosis in boys is highly suggestive of X-linked lymphoproliferative disease--report of three cases

Hypogammaglobulinemia is a common symptom in different immunodeficiencies. It is, however, not usually associated with Epstein-Barr virus (EBV) infections. The X-linked lymphoproliferative disease (XLP) on the other hand shows immunological changes in response to the EBV. Here we report three previously healthy boys, all of which developed persistent hypogammaglobulinemia following severe acute infectious mononucleosis. All three patients revealed T-cell abnormalities including inverted CD4/CD8 and increased CD8(+) T-cell numbers. The number of IFN-gamma-producing T cells were markedly increased in the two patients studied so far. In addition, patient 2 showed mainly T cells, instead of B cells, to be infected with the EBV. Apart from an uncle of patient 3, who died of malignant lymphoma, family history was unremarkable in all cases. All three patients exhibited mutations in the SH2D1A gene, establishing the diagnosis of XLP. Protein expression was found on immunoblot analysis in one patient with a missense mutation. Development of persistent hypogammaglobulinemia after severe primary EBV infection seems to be a specific diagnostic sign for XLP even in males with unremarkable family history.

[Counselling, genetic testing and prevention in women with hereditary breast- and ovarian cancer. Interdisciplinary recommendations of the consortium "Hereditary Breast- and Ovarian Cancer" of the German Cancer AiD]

Women with familial predisposition for breast and ovarian cancer represent a small group of patients with very high risk for developing breast and/ or ovarian cancer before the age of 50 years. The individual breast cancer risk can be assessed by genetic counselling and can be specified by genetic diagnostics. As part of the gynaecological consultation, adequate preventive measures are offered. Psycho-oncological counselling may help in decision making. For hereditary carcinomas, counselling is still not considered as a routine medical care, even though basic and routine preventive measures are insufficient for this group of high risk patients. Within the last years, 12 specialized centres in Germany have developed a patient care concept for women with a familial risk for breast and ovarian cancer. Establishment of these centres for familial breast and ovarian cancer and use of evidence-based medical care was initiated in a nationwide interdisciplinary joint research project and supported by the German Cancer AiD. These measures were integrated in a quality assurance concept for structure, process and result optimization. Thus, all requirements for introducing these services into routine patient management have been fulfilled.

A new genetic locus for X linked progressive cone-rod dystrophy

X linked progressive cone-rod dystrophy (COD) is a retinal disease primarily affecting the cone photoreceptors. The disease is genetically heterogeneous and two loci, COD1 (Xp21.1-11.4) and COD2 (Xq27.2-28), have been previously identified. COD1 was recently shown to be caused by mutations in RPGR exon ORF15 (Xp21.1), the gene that is also responsible for RP3 type retinitis pigmentosa. In this study, we performed a linkage study to map the disease gene in a large Finnish family with X linked cone-rod dystrophy, using a panel of 39 X chromosomal markers. Several recombinations between the disease gene and markers in the Xp21.1-p11.4 region have excluded COD1 as a candidate locus in this family. Consistent with the linkage results, no mutation was detected by direct PCR sequencing of the coding region of RPGR, including exon ORF15. The COD2 locus has been also excluded as the site of the gene on the basis of negative lod score values obtained for COD2 linked markers. The disease causing gene of the studied COD family has been localised between the markers DXS10042 and DXS8060 on Xp11.4-q13.1. Positive pairwise lod scores >3 were obtained for markers DXS993, MAOB, DXS1055, and DXS1194. Since this locus is distinct from the previously identified two loci, COD1 and COD2, our results establish a new third genetic locus for X linked progressive cone-rod dystrophy and further expands our knowledge about the genetic heterogeneity underlying this disease entity.

Familial ovarian dysgerminomas (Swyer syndrome) in females associated with 46 XY-karyotype

An asymptomatic woman (age 38 years) with a family history of ovarian malignancies was referred for presymptomatic genetic testing of mutations in the BRCA genes. A familial Swyer syndrome with the occurrence of dysgerminomas is the most likely diagnosis. However, in our case, all known causes of this heterogeneous disorder have been excluded pointing to the existence of another yet unknown genetic locus. The family history revealed three affected paternal aunts. Two of them developed ovarian malignancies at 13 and 15 years of age, and died at ages 19 and 20. The third aunt, 82 years old, was affected by this disease at the age of 35. She underwent hormonal treatment for 3 years starting at the age of 15 because of primary amenorrhea. Under this treatment she developed nearly complete secondary sexual characteristics. Karyotype analysis revealed a normal male karyotype (46 XY, QFQ). Pelvic ultrasound showed an uterus of normal size, incompatible with an androgen resistance syndrome or a defect in testosterone biosynthesis. We excluded a mutation in the sex-determining region on chromosome Y (SRY) by direct sequencing of the SRY gene. An involvement of the subtelomeric region of chromosome 9p (9p 24.3) recently reported to be involved in XY-sex reversal phenotypes was excluded by molecular testing for loss of heterozygosity as well as fluorescence in situ hybridization studies. Analyses of the DAX1 gene in the dosage sensitive sex reversal locus on chromosome Xp21 by Southern blot analysis showed no duplications.

Comprehensive analysis of 989 patients with breast or ovarian cancer provides BRCA1 and BRCA2 mutation profiles and frequencies for the German population

The main focus of this German-wide multi-center study was to establish a BRCA1/2 mutation profile and to determine family types with high frequencies of mutations in these genes. In a comprehensive study, the entire coding sequences of the breast cancer genes BRCA1 and BRCA2 were analyzed in 989 unrelated patients from German breast/ovarian cancer families. A total of 77 BRCA1 and 63 BRCA2 distinct deleterious mutations were found in 302 patients. More than (1/3) of these mutations are novel and might be specific for the German population. Eighteen common mutations were found in 68% of cases in BRCA1 and 13 recurrent mutations in 44% of cases in BRCA2, facilitating prescreening approaches. Haplotype analysis indicate that 14 out of 20 recurrent mutations are likely originating from a common founder. An additional 50 different rare sequence variants with unknown relevance for tumorigenesis were found in 72 families. Correlation of BRCA1/BRCA2 detection rates with family history identified families with both breast and ovarian cancer to be at highest risk for BRCA1/BRCA2 mutations (43% and 10%, respectively), followed by families with at least 2 premenopausal cases of breast cancer (24% BRCA1 and 13% BRCA2 mutations). These data provide strong evidence for further predisposing genes in the German population. In breast cancer families with 2 or 3 affected females but only a single or no premenopausal case, mutations were detected with low frequencies (about 10% or less for both genes). The decision for or against molecular diagnosis is now aided by considering the expected mutation detection rates that greatly depend on family history and structure.

A novel gene, tendin, is strongly expressed in tendons and ligaments and shows high homology with chondromodulin-I

Chondromodulin-I (CHM1) was identified recently as an angiogenesis inhibitor in cartilage. It is highly expressed in the avascular zones of cartilage but is absent in the late hypertrophic region, which is invaded by blood vessels during enchondral ossification. Blast searches with the C-terminal part of CHM1 in available databases led to the identification of human and mouse cDNAs encoding a new protein, Tendin, that shares high homology with CHM1. Based on computer predictions, Tendin is a type II transmembrane protein containing a putative proteinase cleavage and two glycosylation sites. Northern assays with mouse RNAs demonstrated strong expression of a 1.5-kb tendin transcript in the diaphragm, skeletal muscle, and the eye and low levels of expression in all other tissues investigated. In 17.5-day-old mouse embryos, in situ hybridization revealed high levels of tendin transcript in tendons and ligaments. Additional signals were detected in brain and spinal cord, liver, lung, bowels, thymus, and eye. Cartilage, where CHM1 is found, revealed low levels of tendin m-RNA. In adult mice, tendin is expressed in neurons of all brain regions and the spinal cord. The tendin gene is localized in the human Xq22 region, to which several human diseases have been mapped.

Prevalence of Staphylococcus aureus and staphylococcal enterotoxins in raw pork and uncooked smoked ham--a comparison of classical culturing detection and RFLP-PCR

In many countries Staphylococcus aureus is considered to be the second or third most common pathogen causing outbreaks of food poisoning, only outnumbered by Salmonella spp. and in competition with Clostridium perfringens. Often the consumption of ham or meat containing staphylococcal enterotoxins (SE) is identified as cause of the illness. Thus, to gain an insight into the prevalence of S. aureus and its emetic enterotoxins in raw pork and uncooked smoked ham and to investigate how the prevalence of the pathogen is influenced during the fabrication process, a total of 135 samples of raw pork, salted meat and ready-for-sale uncooked smoked ham were examined for the prevalence of S. aureus and staphylococcal enterotoxins A to D (SEA-SED). To this means classical cultural methods were employed as well as molecular biological techniques (PCR) and the results were compared. In 25.9% of all samples S. aureus was detected by culture whereas 51.1% of the samples showed a positive result when PCR was used for the detection of the pathogen. Fresh meat was contaminated most often. By PCR, 62.2% were identified as being S. aureus positive compared to 57.7% positive samples using the cultural technique. The detection rate during the fabrication process declined significantly. The pathogen was cultivated from 8.9% of the salted meat samples. Here, 55.6% of the samples reacted positively in the PCR, and finally, in approximately a third of the ready-for-sale smoked hams, S. aureus genes were found. From 11.1% of these samples, the pathogen could be isolated by culture. From these results, we conclude that the PCR used in this study is more sensitive than the classical cultural method. By PCR, one or more staphylococcal enterotoxin genes were found in 24 of the 135 examined samples. This means that 34.8% of the staphylococcal strains identified using the PCR technique were enterotoxigenic. Using the SET-RPLA, a percentage of 28.6% enterotoxigenic isolates was ascertained. No staphylococcal enterotoxin formation was detected by the SET-RPLA in ready-for-sale ham, although SE-genes were found by PCR. The detection of SE-genes by PCR is faster and easier to perform than the SET-RPLA.

X-linked ocular albinism (Nettleship-Falls): a novel 29-bp deletion in exon 1. Carrier detection by ophthalmic examination and DNA analysis

BACKGROUND

Mutations in the OA1 gene on the short arm of the X chromosome are known to cause X-linked ocular albinism (x1OA) in males. A four-generation family with this disorder, including asymptomatic carrier females, was investigated by molecular analysis of the OA1 gene.

METHODS

DNA samples were available from 22 individuals of this family, including 6 affected males and 6 obligate carriers. The nine exons of the OA1 gene were amplified and further analyzed by SSCP and sequencing.

RESULTS

A detailed clinical examination of the index patient and two female carriers showed the typical signs of ocular albinism. Visual evoked potential responses showed markedly asymmetrical responses from the two hemispheres in the affected person as well as in the carriers, as a result of misrouting and decussation of optic nerve fibers. Molecular genetic analysis demonstrated a previously undescribed 29-bp deletion at position 225-253 in exon 1 of the OA1 gene, which segregated in the family.

CONCLUSION

Clinical examination combined with molecular genetic analysis enhances the potential for a precise diagnosis for persons at risk of x1OA and provide an accurate basis for genetic counseling.

Complete form of X-linked congenital stationary night blindness: refined mapping and evidence of genetic homogeneity

A number of distinct, partly non-overlapping genetic loci have been reported for the complete type of X-linked congenital stationary night blindness (CSNB1), suggesting genetic heterogeneity. In order to refine the localization of the CSNB1 gene and to demonstrate genetic homogeneity, linkage analysis was performed in two large CSNB1 families. Clinical features consistent with the diagnosis of CSNB1 were documented in five patients from a German seven-generation kindred by full ophthalmological examination including psychophysical and electroretinographical testing. Haplotype analysis in 30 members of the large German family was performed with 38 polymorphic markers predominantly covering the critical region. Linkage analyses defined a locus for CSNB1 with flanking markers DXS8042 and DXS228, refining the interval to 2.5 cM in Xp11.4. In addition, two-point linkage analysis was carried out using the MLINK computer program. In agreement with meiotic breakpoints, lod scores of 3.0 and greater were obtained for markers located to the proximal site of the former 5 cM CSNB consensus interval. A large Dutch CSNB1 family was re-evaluated with markers from the Xp11.4 region, and supports the CSNB1 minimal interval found in the German family. Together with previous results from three unrelated families from Sweden, Sardinia and Great Britain, our results provide evidence of genetic homogeneity in the disorder. Subsequent mutation analyses in CSNB1 patients revealed no pathogenic sequence alterations in DFFRX and CASK genes, but retain candidates for other diseases mapping to that region.

The der(17)t(X;17)(p11;q25) of human alveolar soft part sarcoma fuses the TFE3 transcription factor gene to ASPL, a novel gene at 17q25

Alveolar soft part sarcoma (ASPS) is an unusual tumor with highly characteristic histopathology and ultrastructure, controversial histogenesis, and enigmatic clinical behavior. Recent cytogenetic studies have identified a recurrent der(17) due to a non-reciprocal t(X;17)(p11.2;q25) in this sarcoma. To define the interval containing the Xp11.2 break, we first performed FISH on ASPS cases using YAC probes for OATL1 (Xp11.23) and OATL2 (Xp11.21), and cosmid probes from the intervening genomic region. This localized the breakpoint to a 160 kb interval. The prime candidate within this previously fully sequenced region was TFE3, a transcription factor gene known to be fused to translocation partners on 1 and X in some papillary renal cell carcinomas. Southern blotting using a TFE3 genomic probe identified non-germline bands in several ASPS cases, consistent with rearrangement and possible fusion of TFE3 with a gene on 17q25. Amplification of the 5' portion of cDNAs containing the 3' portion of TFE3 in two different ASPS cases identified a novel sequence, designated ASPL, fused in-frame to TFE3 exon 4 (type 1 fusion) or exon 3 (type 2 fusion). Reverse transcriptase PCR using a forward primer from ASPL and a TFE3 exon 4 reverse primer detected an ASPL-TFE3 fusion transcript in all ASPS cases (12/12: 9 type 1, 3 type 2), establishing the utility of this assay in the diagnosis of ASPS. Using appropriate primers, the reciprocal fusion transcript, TFE3-ASPL, was detected in only one of 12 cases, consistent with the non-reciprocal nature of the translocation in most cases, and supporting ASPL-TFE3 as its oncogenically significant fusion product. ASPL maps to chromosome 17, is ubiquitously expressed, and matches numerous ESTs (Unigene cluster Hs.84128) but no named genes. The ASPL cDNA open reading frame encodes a predicted protein of 476 amino acids that contains within its carboxy-terminal portion of a UBX-like domain that shows significant similarity to predicted proteins of unknown function in several model organisms. The ASPL-TFE3 fusion replaces the N-terminal portion of TFE3 by the fused ASPL sequences, while retaining the TFE3 DNA-binding domain, implicating transcriptional deregulation in the pathogenesis of this tumor, consistent with the biology of several other translocation-associated sarcomas. Oncogene (2001) 20, 48 - 57.

The complete form of X-linked congenital stationary night blindness is caused by mutations in a gene encoding a leucine-rich repeat protein

X-linked congenital stationary night blindness (XLCSNB) is characterized by impaired scotopic vision with associated ocular symptoms such as myopia, hyperopia, nystagmus and reduced visual acuity. Genetic mapping in families with XLCSNB revealed two different loci on the proximal short arm of the X chromosome. These two genetic subtypes can be distinguished on the basis of electroretinogram (ERG) responses and psychophysical testing as a complete (CSNB1) and an incomplete (CSNB2) form. The CSNB1 locus has been mapped to a 5-cM linkage interval in Xp11.4 (refs 2,5-7). Here we construct and analyse a contig between the markers DXS993 and DXS228, leading to the identification of a new gene mutated in CSNB1 patients. It is partially deleted in 3 families and mutation analysis in a further 21 families detected another 13 different mutations. This gene, designated NYX, encodes a protein of 481 amino acids (nyctalopin) and is expressed at low levels in tissues including retina, brain, testis and muscle. The predicted polypeptide is a glycosylphosphatidylinositol (GPI)-anchored extracellular protein with 11 typical and 2 cysteine-rich, leucine-rich repeats (LRRs). This motif is important for protein-protein interactions and members of the LRR superfamily are involved in cell adhesion and axon guidance. Future functional analysis of nyctalopin might therefore give insight into the fine-regulation of cell-cell contacts in the retina.

Mutational hot spot within a new RPGR exon in X-linked retinitis pigmentosa

The gene RPGR was previously identified in the RP3 region of Xp21.1 and shown to be mutated in 10-20% of patients with the progressive retinal degeneration X-linked retinitis pigmentosa (XLRP). The mutations predominantly affected a domain homologous to RCC1, a guanine nucleotide exchange factor for the small GTPase Ran, although they were present in fewer than the 70-75% of XLRP patients predicted from linkage studies. Mutations in the RP2 locus at Xp11.3 were found in a further 10-20% of XLRP patients, as predicted from linkage studies. Because the mutations in the remainder of the XLRP patients may reside in undiscovered exons of RPGR, we sequenced a 172-kb region containing the entire gene. Analysis of the sequence disclosed a new 3' terminal exon that was mutated in 60% of XLRP patients examined. This exon encodes 567 amino acids, with a repetitive domain rich in glutamic acid residues. The sequence is conserved in the mouse, bovine and Fugu rubripes genes. It is preferentially expressed in mouse and bovine retina, further supporting its importance for retinal function. Our results suggest that mutations in RPGR are the only cause of RP3 type XLRP and account for the disease in over 70% of XLRP patients and an estimated 11% of all retinitis pigmentosa patients.

Physical mapping and exclusion of GPR34 as the causative gene for congenital stationary night blindness type 1

X-linked congenital stationary night blindness (CSNB) is a nonprogressive retinal disorder characterized by impaired night vision, variably involving high myopia, nystagmus, decreased visual acuity, and strabismus. Linkage studies have identified two distinct loci for X-linked CSNB1 and CSNB2 on the short arm of chromosome X. The gene mutated in families displaying the "incomplete phenotype" of CSNB (i.e., CSNB2) has recently been identified. To identify novel candidate genes for the "complete form" of CSNB (i.e., CSNB1) we screened the physically vast region Xp11.3-Xp11.4 for cDNA sequences. This led us to identify and map the G protein coupled receptor (GPCR) gene GPR34 to Xp11.4 within 650 kb of the marker DXS993. Deletion screening via Southern blotting and direct sequencing of GPR34 revealed no mutations in 19 unrelated men with CSNB1, excluding a causal role in the disease. However, because of its expression in retinal and neural tissue and the involvement of GPCRs in transmembrane signal transduction, GPR34 remains a putative candidate gene for a number of ocular diseases which also map to the Xp11.4 region.

[The Wiskott-Aldrich syndrome in adulthood]

HISTORY AND ADMISSION FINDINGS

A 24-year-old man with thrombocytopenia was referred for surgical resection of a bleeding polyp of the sigmoid. Examination showed a small haematoma and petechiae on both lower legs. The patient reported that several male family members also had a thrombocytopenic bleeding tendency.

INVESTIGATIONS

Laboratory tests revealed thrombocytopenia (4000 platelets/ml, with small platelets: mean platelet volume [MPV] 5.6 ml). Serum immunoglobulins were normal. A mutation in the Wiskott-Aldrich (W-A) protein gene (intron 7 + 5 G-->A) was demonstrated both in the patient and his 26-year-old brother.

DIAGNOSIS, TREATMENT AND COURSE

The diagnosis of W-A syndrome was made and, with perioperative administration of platelets, the polyp was resected without complication.

CONCLUSION

Most patients with the W-A syndrome die by the time they are aged 10 years, unless appropriate treatment is given. This patient and his brother had a mutation of the W-A protein gene that unusually was in an intron rather than in an exon. Structurally normal W-A proteins were still being formed. This may explain the mild course and late onset of the disease.

Recurrent B-cell non-Hodgkin's lymphoma in two brothers with X-linked lymphoproliferative disease without evidence for Epstein-Barr virus infection

We present two male siblings suffering from recurrent manifestations of B-cell non-Hodgkin's lymphoma (NHL) and recurrent infections of the lower respiratory tract associated with bronchiectasis. Immunodeficiency could not be demonstrated by any laboratory investigation. In both patients, lymphomas developed without evidence for Epstein-Barr virus (EBV) infection, i.e. no antibody response to EBV-specific antigens, negative EBV-PCR (polymerase chain reaction) in peripheral blood cells, and absence of latent membrane protein (LMP) and EBV-encoded RNA (EBER) in lymphoma cells. Molecular analysis of the SH2D1A, the gene for X-linked lymphoproliferative disease (XLP) led to the identification of a deletion in the first exon in both patients. Therefore, we postulate that the genetic defect and the following dysregulation of the B-/T-cell interaction rendered these patients susceptible to the early onset of B-cell NHL and that EBV infection is not an obligate prerequisite.

A new gene involved in X-linked mental retardation identified by analysis of an X;2 balanced translocation

X-linked forms of mental retardation (MR) affect approximately 1 in 600 males and are likely to be highly heterogeneous. They can be categorized into syndromic (MRXS) and nonspecific (MRX) forms. In MRX forms, affected patients have no distinctive clinical or biochemical features. At least five MRX genes have been identified by positional cloning, but each accounts for only 0.5%-1.0% of MRX cases. Here we show that the gene TM4SF2 at Xp11.4 is inactivated by the X breakpoint of an X;2 balanced translocation in a patient with MR. Further investigation led to identification of TM4SF2 mutations in 2 of 33 other MRX families. RNA in situ hybridization showed that TM4SF2 is highly expressed in the central nervous system, including the cerebral cortex and hippocampus. TM4SF2 encodes a member of the tetraspanin family of proteins, which are known to contribute in molecular complexes including beta-1 integrins. We speculate that through this interaction, TM4SF2 might have a role in the control of neurite outgrowth.

Epstein-Barr virus-negative boys with non-Hodgkin lymphoma are mutated in the SH2D1A gene, as are patients with X-linked lymphoproliferative disease (XLP)

X-linked lymphoproliferative disease (XLP) is a primary immunodeficiency, which most often manifests itself after Epstein-Barr virus (EBV) infection. The main clinical phenotypes include fulminant or fatal infectious mononucleosis, dysgammaglobulinaemia and malignant lymphoma. We have recently cloned the SH2D1A gene, which has been shown to be mutated in approximately 70% of XLP patients. Now we report five novel SH2D1A mutations in patients from five unrelated XLP families. No mutations were found in another three XLP families. In three boys with early onset non-Hodgkin lymphoma (NHL) from two unrelated families a deletion of SH2D1A exon 1 and a splice site mutation were found, respectively. These patients did not show any laboratory or clinical signs of a previous EBV infection. A fourth EBV-uninfected and unrelated boy with a stop mutation in the SH2D1A gene shows only signs of dysgammaglobulinaemia. Development of dysgamma-globulinaemia and lymphoma without evidence of prior EBV infection in four of our patients suggests that EBV is unrelated to these phenotypes, in contrast to fulminant or fatal infectious mononucleosis. The role of SH2D1A as a putative tumour suppressor gene remains to be investigated.