Partial monosomy14q involving FOXG1 and NOVA1 in an infant with microcephaly, seizures and severe developmental delay.

BACKGROUND: FOXG1 gene mutations have been associated with the congenital variant of Rett syndrome (RTT) since the initial description of two patients in 2008. The on-going accumulation of clinical data suggests that the FOXG1-variant of RTT forms a distinguishable phenotype, consisting mainly of postnatal microcephaly, seizures, hypotonia, developmental delay and corpus callosum agenesis. CASE PRESENTATION: We report a 6-month-old female infant, born at 38 weeks of gestation after in vitro fertilization, who presented with feeding difficulties, irritability and developmental delay from the first months of life. Microcephaly with bitemporal narrowing, dyspraxia, poor eye contact and strabismus were also noted. At 10 months, the proband exhibited focal seizures and required valproic acid treatment. Array-Comparative Genomic Hybridization revealed a 4.09 Mb deletion in 14q12 region, encompassing the FOXG1 and NOVA1 genes. The proband presented similar feature with patients with 14q12 deletions except for dysgenesis of corpus callosum. Disruption of the NOVA1 gene which promotes the motor neurons apoptosis has not yet been linked to any human phenotypes and it is uncertain if it affects our patient's phenotype. CONCLUSIONS: Since our patient is the first reported case with deletion of both genes (FOXG1-NOVA1), thorough clinical follow up would further delineate the Congenital Rett-Variant phenotypes.

Two high throughput technologies to detect segmental aneuploidies identify new Williams-Beuren syndrome patients with atypical deletions.

OBJECTIVE: To develop and compare two new technologies for diagnosing a contiguous gene syndrome, the Williams-Beuren syndrome (WBS). METHODS: The first proposed method, named paralogous sequence quantification (PSQ), is based on the use of paralogous sequences located on different chromosomes and quantification of specific mismatches present at these loci using pyrosequencing technology. The second exploits quantitative real time polymerase chain reaction (QPCR) to assess the relative quantity of an analysed locus. RESULTS: A correct and unambiguous diagnosis was obtained for 100% of the analysed samples with either technique (n = 165 and n = 155, respectively). These methods allowed the identification of two patients with atypical deletions in a cohort of 182 WBS patients. Both patients presented with mild facial anomalies, mild mental retardation with impaired visuospatial cognition, supravalvar aortic stenosis, and normal growth indices. These observations are consistent with the involvement of GTF2IRD1 or GTF2I in some of the WBS facial features. CONCLUSIONS: Both PSQ and QPCR are robust, easy to interpret, and simple to set up. They represent a competitive alternative for the diagnosis of segmental aneuploidies in clinical laboratories. They have advantages over fluorescence in situ hybridisation or microsatellites/SNP genotyping for detecting short segmental aneuploidies as the former is costly and labour intensive while the latter depends on the informativeness of the polymorphisms.

[Identification of an experimental model of partial portocaval shunt]. / Identificazione di un modello sperimentale di derivazione porto-cava parziale.

Portacaval shunt with interposition of 6 mm H-graft of PTFE is a real partial shunt. In this experimental study, the operation has been well tolerated and has been compared with 8 mm H-graft and direct "vein to vein" portacaval shunt. Intraoperative data show that 6 mm is the ideal diameter for a portacaval shunt to prompt an experimental model based on partial decompression of portal bed in animals in this size.

Bradykinin and its metabolite, Arg-Pro-Pro-Gly-Phe, are selective inhibitors of alpha-thrombin-induced platelet activation.

BACKGROUND: Plasma kininogens are selective inhibitors of alpha-thrombin activation of platelets and endothelial cells. In the present study, we localized the alpha-thrombin inhibitory sequence of kininogens and describe its mechanism of action. METHODS AND RESULTS: Bradykinin and an analogue, MKRPPGFSPFRSSRIG, inhibited alpha-thrombin-induced platelet aggregation and secretion with an IC50 of 0.25 and 1 mmol/L and of 0.23 and 0.5 mmol/L, respectively. The minimal inhibitory peptide was RPPGF. Bradykinin and its analogues did not inhibit ADP-, collagen-, U46619-, or SFLLRN-induced platelet activation or the ability of alpha-thrombin to cleave chromogenic substrates, clot fibrinogen, or block alpha-thrombin binding to platelets. Bradykinin, MKRPPGFSPFRSSRIG, and RPPGF abolished alpha-thrombin-induced (1 nmol/L) calcium mobilization. On flow cytometry, bradykinin and MKRPPGFSPFRSSRIG blocked alpha-thrombin from removing the epitope of its cleavage site on the cloned thrombin receptor. Furthermore, peptide RPPGF or high-molecular-weight kininogen prevented alpha-thrombin from cleaving the thrombin receptor peptide, NATLDPRSFLLR, between arginine and serine. CONCLUSIONS: These results indicate that bradykinin and its metabolites are selective antithrombins by preventing alpha-thrombin cleavage of the cloned thrombin receptor between arginine-41 and serine-42. These newly recognized antithrombin peptides, which are termed thrombostatins, contribute to the cardioprotective nature of kinins.

Administration of gamma interferon in human subjects decreases plasminogen activation and fibrinolysis without influencing C1 inhibitor.

Recombinant gamma interferon (rHuIFN-gamma) has been recognized to increase mRNA and protein levels of C1 inhibitor (C1 INH) in various human cells. Further, when administered to patients with colon cancer, it increased plasma C1 INH levels. A prospective trial was initiated to determine whether rHuIFN-gamma could elevate plasma C1 INH levels in six normal volunteers and two patients with type I angioedema. After 1 month of observation of plasma C1 INH levels, rHuIFN-gamma was administered subcutaneously at 25 micrograms/M2 daily for 4 consecutive days. All healthy volunteers and patients experienced local erythema, headache, myalgias, and chills during the administration of rHuIFN-gamma. C1 INH, prekallikrein, high-molecular-weight kininogen, and factor XII levels in plasma were not influenced by the rHuIFN-gamma administration. One patient with hereditary angioedema (HAE) had an attack of angioedema 3 days after completion of rHuIFN-gamma therapy. During the attack, circulating cleaved high-molecular-weight kininogen, kallikrein-alpha 2-macroglobulin complexes, and an altered 50 kd form of kallikrein were detected in the patient's plasma. Additional studies showed that rHuIFN-gamma treatment resulted in decreased total fibrinolytic activity. It was found that immediately after rHuIFN-gamma treatment, tissue plasminogen activator activity and antigen levels were not significantly decreased in volunteers. Plasminogen activator inhibitor levels rose significantly, but this activity was not due to plasminogen activator inhibitor-1 antigen, whose value significantly fell. These data suggest that rHuIFN-gamma may stimulate the expression of another plasminogen activator inhibitor.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of platelet C1 inhibitor.

Human platelets contain a pool of C1 inhibitor (C1 INH) distinct from that in plasma. Twelve normal platelet samples washed by centrifugation had a mean platelet C1 INH antigen level of 19.3 +/- 2.8 ng (mean +/- SEM) per 10(8) platelets. These values contrast with the mean +/- SEM platelet C1 INH antigen level of 6.1 +/- 0.9 per 10(8) platelets from 12 C1 INH-deficient patients. The level of platelet C1 INH correlated (r = .7) with the level of plasma C1 INH in normal individuals and patients with classic hereditary angioedema. Platelet C1 INH, like plasma C1 INH, was a 105-Kd protein on immunoblots of solubilized platelets and in thrombin- or collagen-induced platelet releasates. On indirect immunofluorescence, morphologically and immunochemically identifiable elutriated human megakaryocytes had C1 INH antigen. Using nested primer polymerase chain reaction, C1 INH mRNA was detected in megakaryocytes. When activated, human platelets expressed a portion of their total pool of C1 INH antigen on their membrane. Using a competitive enzyme-linked immunosorbent assay for C1 INH as a quantitative, indirect antibody consumption assay, the surface of unstimulated platelets had 0.55 +/- 0.4 ng C1 INH/10(8) platelets (mean +/- SEM). When activated with thrombin, platelets secreted 7.37 +/- 2.2 ng C1 INH/10(8) platelets into the suspension buffer and simultaneously expressed 4.4 +/- 1.2 ng C1 INH/10(8) platelets on their external membrane. These studies showed that activated platelets secreted 38% of their C1 INH and externalized another 23% of the total platelet C1 INH on their membrane. Furthermore, in 125I-anti-C1 INH Fab' binding experiments to platelets, about 8 ng of the antibody fragment specifically bound to 10(8) activated platelets. These data suggest that level of platelet C1 INH packaged into platelet alpha-granules is modulated by the amount of protein produced in megakaryocytes. Platelet alpha-granule C1 INH can both be secreted from platelets and expressed on their activated membranes. The cell membrane expression of C1 INH may be important to modulate the activity of the proteases of the complement and contact systems of plasma proteolysis in the microenvironment of the inflammatory response.