A novel germline mutation of the VHL gene in a Greek family with Von Hippel–Lindau disease

Von Hippel–Lindau disease (VHL) is an autosomal dominant disorder, caused by mutations of the VHL gene showing a strong genotype–phenotype correlation. The present report concerns a 16-year-old girl with VHL (retinal, spinal cord and cerebellar haemangioblastomas and pancreatic cysts), her father (retinal and spinal cord haemangioblastomas) and the phenotypically healthy mother and younger brother and sister. DNA extraction, PCR and direct sequencing of the VHL entire coding and intronic flanking sequences, were performed according to standard procedures. In the index patient and her father a novel heterozygous germline was identified; nonsense mutation (p.145X) in exon 2 of VHL, leading to a truncated VHL protein lacking the last 66 amino acids. This is the first report of a novel VHL mutation in patients with VHL associated with haemangioblastomas and pancreatic cysts but not renal cell carcinoma

Mutation Spectrum of the ABCA4 Gene in a Greek Cohort with Stargardt Disease: Identification of Novel Mutations and Evidence of Three Prevalent Mutated Alleles

Aim. To evaluate the frequency and pattern of disease-associated mutations of ABCA4 gene among Greek patients with presumed Stargardt disease (STGD1). Materials and Methods. A total of 59 patients were analyzed for ABCA4 mutations using the ABCR400 microarray and PCR-based sequencing of all coding exons and flanking intronic regions. MLPA analysis as well as sequencing of two regions in introns 30 and 36 reported earlier to harbor deep intronic disease-associated variants was used in 4 selected cases. Results. An overall detection rate of at least one mutant allele was achieved in 52 of the 59 patients (88.1%). Direct sequencing improved significantly the complete characterization rate, that is, identification of two mutations compared to the microarray analysis (93.1% versus 50%). In total, 40 distinct potentially disease-causing variants of the ABCA4 gene were detected, including six previously unreported potentially pathogenic variants. Among the disease-causing variants, in this cohort, the most frequent was c.5714+5G>A representing 16.1%, while p.Gly1961Glu and p.Leu541Pro represented 15.2% and 8.5%, respectively. Conclusions. By using a combination of methods, we completely molecularly diagnosed 48 of the 59 patients studied. In addition, we identified six previously unreported, potentially pathogenic ABCA4 mutations

Does somatostatin have a role in the regulation of cortisol secretion in primary pigmented nodular adrenocortical disease (PPNAD)? A clinical and in vitro investigation

Context: Somatostatin (SST) receptors (SSTRs) are expressed in a number of tissues, including the adrenal cortex, but their role in cortisol secretion has not been well characterized. Objectives: The objective of the study was to investigate the expression of SSTRs in the adrenal cortex and cultured adrenocortical cells from primary pigmented nodular adrenocortical disease (PPNAD) tissues and to test the effect of a single injection of 100 g of the SST analog octreotide on cortisol secretion in patients with PPNAD. Setting and Design: The study was conducted at an academic research laboratory and clinical research center. Expression of SSTRs was examined in 26 PPNAD tissues and the immortalized PPNAD cell line CAR47. Ten subjects with PPNAD underwent a randomized, single-blind, crossover study of their cortisol secretion every 30 minutes over 12 hours (6:00 PM to 6:00 AM) before and after the midnight administration of octreotide 100 μg sc. Methods: SSTRs expression was investigated by quantitative PCR and immunohistochemistry. The CAR47and primary cell lines were studied in vitro. The data of the 10 patients were analyzed before and after the administration of octreotide. Results: All SSTRs, especially SSTR1-3, were expressed in PPNAD at significantly higher levels than in normal adrenal. SST was found to differentially regulate expression of its own receptors in the CAR47 cell line. However, the administration of octreotide to patients with PPNAD did not significantly affect cortisol secretion. Conclusions: SSTRs are overexpressed in PPNAD tissues in comparison with normal adrenal cortex. Octreotide did not exert any significant effect on cortisol secretion in a short clinical pilot study in a small number of patients with PPNAD, but long-acting SST analogs targeting multiple SSTRs may be worth investigating in this condition