t(11;14)(q23;q32) involving IGH and DDX6 in nodal marginal zone lymphoma.

Nodal marginal zone lymphoma (NMZL) is a primary nodal B-cell lymphoma that shares morphological and immunophenotypic characteristics with extranodal and splenic marginal zone lymphoma. Data on altered genes and signaling pathways are scarce in this rare tumor entity. To gain further insights into the genetic background of NMZL, seven cases were investigated by microarray analysis, G-banding, and FISH. Chromosomal imbalances were observed in 3/7 cases (43%) with gains of chromosome arms 1q, 8q, and 12q being the most frequent findings. Furthermore, we identified a translocation t(11;14)(q23;q32) involving IGH and DDX6. Chromosomal walking, expression analysis, siRNA-mediated gene knockdown and a yeast two hybrid screen were performed for further characterization of the translocation in vitro. In siRNA experiments, DDX6 appeared not to be involved in NF-κB activation as frequently observed for genes promoting lymphomagenesis but was found to interfere with the expression of BCL6 and BCL2 in an NF-κB independent manner. In conclusion, we identified several unbalanced aberrations and a t(11;14) involving IGH and DDX6 providing evidence for a contribution of DDX6 to lymphomagenesis by deregulation of BCL6 in NMZL.

Neonatal screening for lysosomal storage disorders: feasibility and incidence from a nationwide study in Austria.

BACKGROUND: The interest in neonatal screening for lysosomal storage disorders has increased substantially because of newly developed enzyme replacement therapies, the need for early diagnosis, and technical advances. We tested for Gaucher's disease, Pompe's disease, Fabry's disease, and Niemann-Pick disease types A and B in an anonymous prospective nationwide screening study that included genetic mutation analysis to assess the practicality and appropriateness of including these disorders in neonatal screening panels. METHODS: Specimens from dried blood spots of 34,736 newborn babies were collected consecutively from January, 2010 to July, 2010, as part of the national routine Austrian newborn screening programme. Anonymised samples were analysed for enzyme activities of acid ß-glucocerebrosidase, α-galactosidase, α-glucosidase, and acid sphingomyelinase by electrospray ionisation tandem mass spectrometry. Genetic mutation analyses were done in samples with suspected enzyme deficiency. FINDINGS: All 34,736 samples were analysed successfully by the multiplex screening assay. Low enzyme activities were detected in 38 babies. Mutation analysis confirmed lysosomal storage disorders in 15 of them. The most frequent mutations were found for Fabry's disease (1 per 3859 births), followed by Pompe's disease (1 per 8684), and Gaucher's disease (1 per 17,368). The positive predictive values were 32% (95% CI 16-52), 80% (28-99), and 50% (7-93), respectively. Mutational analysis detected predominantly missense mutations associated with a late-onset phenotype. INTERPRETATION: The combined overall proportion of infants carrying a mutation for lysosomal storage disorders was higher than expected. Neonatal screening for lysosomal storage disorders is likely to raise challenges for primary health-care providers. Furthermore, the high frequency of late-onset mutations makes lysosomal storage disorders a broad health problem beyond childhood. FUNDING: Austrian Ministry of Health, Family, and Women.

Prenatal genetic diagnosis using microarray analysis in fetuses with congenital heart defects.

OBJECTIVE: To evaluate the use of microarray analysis as a tool for the detection of submicroscopic chromosomal aberrations in prenatal diagnosis. METHODS: Twelve consecutive singleton fetuses with congenital heart defects but normal karyotype and normal fluorescence in situ hybridization results for the DiGeorge region were examined for chromosomal aberrations by genomic microarray analysis. Results were confirmed by fluorescence in situ hybridization and quantitative real time-polymerase chain reaction. RESULTS: At 1 Mb resolution, potentially causal copy number variations were identified in 3 out of 12 fetuses (25%) comprising a 9 Mb q terminal deletion on chromosome 15, a 3.5 Mb duplication in the critical region for the Potocki-Lupski syndrome on chromosome 17 and a mosaic trisomy 7. At higher resolution, aberrations with uncertain significance were identified in a further three cases (25%). CONCLUSION: In our study, the application of microarray analysis in prenatal testing proved to be a valuable tool for the identification of submicroscopic chromosomal aberrations where conventional cytogenetic methods failed. Selection of appropriate resolution was found to be critical to obtain reliable, diagnostically conclusive data.

Autoimmune lymphoproliferative syndrome (ALPS) caused by Fas (CD95) mutation mimicking sarcoidosis.

Autoimmune lymphoproliferative syndrome (ALPS) is an inherited disorder associated with defects in apoptosis, characterized by childhood onset of lymphadenopathy, splenomegaly, hyperimmunoglobulinemia, and autoimmune disease. ALPS is most frequently associated with a mutation in the cell death receptor Fas (CD95). Very rarely a mutation in caspase 10 is present. An increase of CD4/CD8 double negative T cells in the peripheral blood and lymph nodes is a feature characteristic of ALPS. Additionally, histiocytic proliferations resembling sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) were reported recently in patients with ALPS. In the rare cases with a caspase 10 mutation an accumulation of dendritic cells in lymphoid organs was noted. We describe a different, sarcoidosislike, histiocytic infiltration of lymph nodes that persisted for years in a girl, that was initially supposed to suffer from sarcoidosis, but was eventually diagnosed as ALPS, associated with a missense mutation in the intracellular death domain of Fas. This sarcoidosislike histologic picture extends the spectrum of histiocytic lymph node alterations observed in ALPS and alerts of a potential diagnostic pitfall.

Global and single gene DNA methylation in umbilical cord blood cells after elective caesarean: a pilot study.

OBJECTIVE: To evaluate global and single gene methylation patterns as a sign for epigenetic modulation of the immune system in infants born by elective cesarean section (CS) and vaginal delivery (VD). STUDY DESIGN: For this prospective pilot study a two step approach was chosen. Initially 41 newborn infants comprising 23 delivered by VD and 18 delivered by elective CS were included. Global DNA methylation of umbilical cord blood was determined. In a second step, methylation status of 96 single genes linked to T cell activation, cytokine production, inflammatory response, and stem cell transcription was evaluated in 48 newborn infants, 20 delivered by VD and 28 delivered by CS. RESULTS: Global methylation did not differ significantly between CS and VD (p=0.732). The methylation status was low (threshold: ≤3%) for the majority of single genes (n=92) in both groups. FOXP3, CD7, ELA2, and IRF1 showed hypermethylation in both groups. In the CS group, ELA2 (p<0.001) and IRF1(p =0.017) showed significantly higher methylation compared to the VD group. CONCLUSION: We found no difference in global methylation between newborn infants in the VD group compared to the elective CS group. Methylation of single genes was significantly higher in newborn infants delivered by elective CS. Further research is needed to determine the significance of theses findings.

A novel homozygous mutation in the parathyroid hormone gene (PTH) in a girl with isolated hypoparathyroidism.

CASE REPORT: A female patient with consanguineous parents presented with severe symptomatic hypocalcemia (1.62mmol/l) at the age of 4 months. Treatment with oral 1,25-(OH)2-vitamin D and calcium carbonate was started and serum calcium concentrations were stabilized at the lower end of the normal range. Subsequently she developed normally and had no evidence for additional abnormalities. Over the next 6 years of observation, serum levels of PTH were always low but detectable (5.3-2.5pg/ml; normal: 15-65pg/ml) resulting in the diagnosis of isolated hypoparathyroidism. Disturbances in the vitamin-D metabolism, autoimmune polyendocrine syndrome (APS), chromosomal anomalies or mutations in the calcium-sensing receptor gene (CaSR) were excluded. Nucleotide sequence analysis of PTH revealed the presence of a homozygous point mutation (c.68C>A) in exon 2 that introduces a premature termination codon (p.Ser23X in the Pre- sequence of PTH) resulting in a non-functional PTH-precursor. CONCLUSION: A novel, homozygous PTH mutations was identified, which is obviously a very rare cause of isolated hypoparathyroidism (IHP). Although activating CaSR mutations are the most common cause of hypoparathyroidism, analysis of the PTH gene should be considered in those IHP patients in whom a CaSR has been excluded, particularly if the parents are likely to be consanguineous.

Interleukin-1 beta gene polymorphisms and preterm birth.

OBJECTIVE: To investigate the association between two genetic variations in the Interleukin-1 beta (IL1B) gene and preterm birth. STUDY DESIGN: In this case-control study we tested the allelic distribution of two of its common polymorphisms (IL1B +3953C>T [rs1143634], IL1B -511C>T [rs16944]) in one hundred women with preterm birth and one hundred healthy women with at least one uncomplicated full term pregnancy and no history of preterm birth. RESULTS: A significant association was found between the presence of the IL1B +3953C>T polymorphism and preterm birth (p=0.049, OR 0.6 [0.3-1.0]). No significant association was found between the IL1B -511C>T polymorphism and preterm birth (p=0.471, OR 1.3 [0.7-2.3]). CONCLUSION: Our findings suggest that the IL1B +3953C>T polymorphism is associated with a risk reduction for preterm birth in Caucasian women, possibly by altering the inflammatory response during pregnancy.

MAPKAP kinase 2 overexpression influences prognosis in gastrointestinal stromal tumors and associates with copy number variations on chromosome 1 and expression of p38 MAP kinase and ETV1.

PURPOSE: ETV1 has been proposed to be activated by KIT mutations in gastrointestinal stromal tumors (GIST). The aim of the study was to evaluate the clinical role of ETV1 and associated proteins in GIST. EXPERIMENTAL DESIGN: Expressions of ETV1, MAPKAP kinase 2 (MAPKAPK2), phosphorylated p38 MAP kinase (pp38), phosphorylated MSK1 (pMSK1), phosphorylated RSK1, COP1, and KIT protein were determined immunohistochemically in 139 GISTs. Sequence analysis of KIT, PDGFRA, and MAPKAPK2 and FISHs of ETV1 as well as chromosomes 1 and 7 were done. RESULTS: Prominent ETV1 expression was seen in 50% of GISTs, but no correlation with clinical outcome was found. Correlation of ETV1 expression and KIT mutation was seen in 60% of cases. MAPKAPK2 overexpression (n = 62/44.6%) correlated with pp38 expression (P = 0.021, χ(2) test) and alterations of chromosome 1 (n = 17, P = 0.024, χ(2) test). In one of 20 sequenced cases with high MAKAPK2 expression, a putative damaging MAPKAPK2 gene mutation was found. All relapsing GISTs with very low/low risk according to Fletcher showed high MAPKAPK2 and KIT expression. MAPKAPK2 overexpression was an independent prognostic factor for disease-free survival (P = 0.006, Cox regression). CONCLUSION: ETV1 is not universally overexpressed in GIST and seems to also be induced by pathways other than KIT mutation. Nevertheless, its clinical relevance is low. Overexpression of ETV1 inhibitor MAPKAPK2 is associated with shorter survival in GIST, indicating a clinically relevant role of this gene not reported previously. Patients with low-risk GISTs showing MAPKAPK2 overexpression might profit from early adjuvant tyrosine kinase inhibitor therapy.

Value and limitations of immunohistochemistry and gene sequencing for detection of the IDH1-R132H mutation in diffuse glioma biopsy specimens.

To assess the value of anti-isocitrate dehydrogenase 1 (IDH1) immunohistochemistry for evaluating diffuse gliomas, we analyzed anti-IDH1-R132H immunohistochemistry using monoclonal antibodies DIA-H09 and IMab-1 and IDH1 gene sequencing in formalin-fixed and paraffin-embedded biopsy samples of 95 diffuse gliomas. We found concordant immunostaining results using the 2 antibodies in 94 (98.9%) of the 95 cases, but DIA-H09 generally showed a higher signal-to-background ratio than IMab-1 did. Fifty-five percent of cases showed anti-IDH1-R132H immunostaining of virtually all tumor cells and 15% of only a fraction of tumor cells. All cases with complete or partial immunostaining of the tumor tissue carried the IDH1-R132H mutation. In all cases with negative immunostaining results (approximately 30%), genetic analysis showed IDH1 wild-type or non-R132H-IDH1 mutations. In a single tiny biopsy, both anti-IDH1-R132H antibodies showed immunoreactivity, but genetic testing was inconclusive. Our data confirm anti-IDH1-R132H immunostaining as a reliable method for evaluation of IDH1 gene mutation status. They also suggest the following: (i) in some cases, nonspecific background staining or regional heterogeneity of IDH1-R132H protein expression may necessitate confirmatory genetic analysis; (ii) for individual cases, anti-IDH1-R132H immunostaining may not reliably identify infiltrating tumor cells admixed with preexisting or reactive glial cells; and (iii) in tiny biopsies, immunohistochemistry may be more sensitive for detection of IDH1-R132H mutation than genetic analysis.

PRT1 of Arabidopsis is a ubiquitin protein ligase of the plant N-end rule pathway with specificity for aromatic amino-terminal residues.

The gene PRT1 of Arabidopsis, encoding a 45-kD protein with two RING finger domains, is essential for the degradation of F-dihydrofolate reductase, a model substrate of the N-end rule pathway of protein degradation. We have determined the function of PRT1 by expression in yeast (Saccharomyces cerevisiae). PRT1 can act as a ubiquitin protein ligase in the heterologous host. The identified substrates of PRT1 have an aromatic residue at their amino-terminus, indicating that PRT1 mediates degradation of N-end rule substrates with aromatic termini but not of those with aliphatic or basic amino-termini. Expression of model substrates in mutant and wild-type plants confirmed this substrate specificity. A ligase activity exclusively devoted to aromatic amino-termini of the N-end rule pathway is apparently unique to plants. The results presented also imply that other known substrates of the plant N-end rule pathway are ubiquitylated by one or more different ubiquitin protein ligases.