PNET/ESFT of the cranial vault: a case report.

A case of peripheral PNET (PNET/ESFT) of the cranial vault is described. A 56-year-old woman showed a mass with a large cyst in the right temporal region, adherent to the meninges, which caused a left hemiparesis with headache and confusion. The mass was totally removed. The histological examination showed a dense proliferation of small elements, organized in lobules separated by reticulin septa. Many circumscribed necroses, vessels with a thick handcuff of reticulin, a diffuse mucous degeneration and abundant mitoses were present. The cells were positive for Vimentin and CD99. RT-PCR revealed the EWS/FLI1 fusion transcript of the t(11,22) (q24;q12) translocation. The patient presented is the oldest one of the rare cases of dura-based meningioma-mimicking pPNETs till now described. In line with the possible origin from peripheral nerves or roots of cauda equina of non-intracranial tumors, those of the vault may derive from peripheral sensory nerves of the dura. The differential diagnosis must be made with cPNETs which show a worse prognosis and both can benefit from a different chemotherapy.

A family-based study does not confirm the association of MYO9B with celiac disease in the Italian population.

Association between Myosin IXB (MYO9B) gene polymorphisms and celiac disease (CD) was recently detected by a case-control association study in the Dutch, but not confirmed in the British and Swedish/Norwegian populations. We tested the association between CD and the three most associated single nucleotide polymorphisms (SNPs) in the Dutch study by the transmission disequilibrium test in the Italian population. A total of 252 pediatric patients and 504 parents were genotyped. No transmission distortion was detected either for the single SNPs or for their haplotypic combinations. Control allele frequencies, calculated from untransmitted alleles, were significantly different from those of the Dutch control population. Conversely, allele frequencies were very similar in Italian, British, Swedish/Norwegian and Dutch patients. In conclusion, MYO9B is not involved in CD susceptibility in the Italian population. The difference with the Dutch result might be explained by an imperfect selection of the Dutch controls.

Association tests with systemic lupus erythematosus (SLE) of IL10 markers indicate a direct involvement of a CA repeat in the 5' regulatory region.

Many lines of evidence suggest that IL10 is a strong candidate gene for systemic lupus erythematosus (SLE) susceptibility. In our previously reported study an allele (IL10.G-140bp) of the microsatellite IL10.G located at position -1100 was significantly increased in Italian SLE patients in comparison with controls. Starting from this observation, we tested if sequence variations in the vicinity of IL10.G were more strongly associated with SLE. We performed a comprehensive association study including 26 SNPs (of which four were newly identified in the present study by DHPLC analysis) spanning 8.5 Kb of the 5' flanking and the transcribed region of the IL10 gene. The association study was performed by the DNA pool method on an extended panel of Italian patients (205) and controls (631). Haplotypic associations were studied by individual typing of seven selected markers surrounding IL10.G. Gene, genotype and haplotype frequencies were not significantly different in patients and controls. Thus the IL10.G microsatellite remains to date the only IL10 marker associated with SLE in our population. A meta-analysis of all published results indicates a possible direct role of the IL10.G repeat number in SLE susceptibility.

The IL12B gene does not confer susceptibility to coeliac disease.

Coeliac disease (CD) is a chronic inflammatory disorder where dietary gluten is not tolerated. In the lesion there are gluten reactive T cells predominantly secreting gamma-interferon. Both HLA and non-HLA genes contribute to CD susceptibility. Interleukin-12 (IL-12) regulates gamma-interferon production. The IL12B gene is located in a region (5q31.1-33.1) where there is evidence for linkage with CD. Allele 1 of an IL12B 3'UTR single-nucleotide polymorphism leads to increased expression of IL-12, and was recently implicated in susceptibility for type 1 diabetes (T1D). We found no evidence for association of allele 1 to CD by the transmission/disequilibrium test or case-control approach. No increased frequency was observed in patients belonging to families where the disease was linked to markers on chromosome 5q. Unlike T1D, allele 1 does not appear to confer susceptibility to CD.

Determination of SNP allele frequencies in pooled DNAs by primer extension genotyping and denaturing high-performance liquid chromatography.

By testing DNA pools rather than single samples the number of tests for a case-control association study can be decreased to only two for each marker: one on the patient and one on the control pool. A fundamental requirement is that each pool represents the frequency of the markers in the corresponding population beyond the influence of experimental errors. Consequently the latter must be carefully determined. To this aim, we prepared pools of different size (49-402 individuals) with accurately quantified DNAs, estimated the allelic frequencies in the pools of two SNPs by primer extension genotyping followed by DHPLC analysis and compared them with the real frequencies determined in the single samples. Our data show that (1) the method is highly reproducible: the standard deviation of repeated determinations was +/-0.014; (2) the experimental error (i.e., the discrepancy between the estimated and real frequencies) was +/-0.013 (95% C.I.: 0.0098-0.0165). The magnitude of this error was not correlated to the pool size or to the type of SNP. The effect of the observed experimental error on the power of the association test was evaluated. We conclude that this method constitutes an efficient tool for high-throughput association screenings provided that the experimental error is low. We therefore recommend that before a pool is used for extensive association studies, its quality, i.e., the experimental error, is verified by determining the difference between estimated and real frequencies for at least one marker.