This molecular fingerprint strongly argues against the clinical efficacy of BRAF-inhibitors, but could candidate primary sinonasal mucosal melanomas to therapeutic strategies targeting RAS and KIT mutations or inhibiting PI3K-Akt-mTOR pathway.
Absent/low-intensity GS expression pattern represents a valuable biomarker of both epilepsy and overall survival in GBM.
BackgroundAlpha-1 antitrypsin (AAT) is the most abundant circulating antiprotease and is a member of the serine protease inhibitor (SERPIN) superfamily. The gene encoding AAT is the highly polymorphic SERPINA1 gene, found at 14q32.1. Mutations in the SERPINA1 gene can lead to AAT deficiency (AATD) which is associated with a substantially increased risk of lung and liver disease. The most common pathogenic AAT variant is Z (Glu342Lys) which causes AAT to misfold and polymerise within hepatocytes and other AAT-producing cells. A group of rare mutations causing AATD, termed Null or Q0, are characterised by a complete absence of AAT in the plasma. While ultra rare, these mutations confer a particularly high risk of emphysema.MethodsWe performed the determination of AAT serum levels by a rate immune nephelometric method or by immune turbidimetry. The phenotype was determined by isoelectric focusing analysis on agarose gel with specific immunological detection. DNA was isolated from whole peripheral blood or dried blood spot (DBS) samples using a commercial extraction kit. The new mutations were identified by sequencing all coding exons (II-V) of the SERPINA1 gene.ResultsWe have found eight previously unidentified SERPINA1 Null mutations, named: Q0cork, Q0perugia, Q0brescia, Q0torino, Q0cosenza, Q0pordenone, Q0lampedusa, and Q0dublin . Analysis of clinical characteristics revealed evidence of the recurrence of lung symptoms (dyspnoea, cough) and lung diseases (emphysema, asthma, chronic bronchitis) in M/Null subjects, over 45 years-old, irrespective of smoking.ConclusionsWe have added eight more mutations to the list of SERPINA1 Null alleles. This study underlines that the laboratory diagnosis of AATD is not just a matter of degree, because the precise determination of the deficiency and Null alleles carried by an AATD individual may help to evaluate the risk for the lung disease.Electronic supplementary materialThe online version of this article (doi:10.1186/s13023-014-0172-y) contains supplementary material, which is available to authorized users.
The proposita suffered from liver cirrhosis and biopsy showed type 1 membrane-bound fiberglass inclusions. The hepatic inclusion bodies were weakly periodic acid-Schiff diastase-positive, and on immunoperoxidase staining reacted specifically with anti-fibrinogen antisera. Coagulation investigations revealed low functional and antigenic fibrinogen together with a prolonged thrombin time of 37 seconds (normal, 17 to 22 seconds) suggestive of a hypodysfibrinogenemia. DNA sequencing of all three fibrinogen genes showed a single heterozygous mutation of GGG (Gly)-->CGG (Arg) at codon 284 of the gamma-chain gene. However, examination of purified fibrinogen chains by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, reverse-phase high-performance liquid chromatography, ion-exchange high-performance liquid chromatography, and isoelectric focusing, failed to show any evidence of the mutant gamma(Br) chain in plasma fibrinogen. This finding was substantiated by electrospray ionization mass spectrometry, which showed only a normal gamma (and Bbeta) chain mass, but a large increase in the portion of their disialo isoforms. We speculate that misfolding of the variant protein causes hepatic retention and the subsequent hypofibrinogenemia, and that the functional defect (dysfibrinogenemia) results from hypersialylation of otherwise normal Bbeta and gamma chains consequent to the liver cirrhosis. These conclusions were supported by studies on six other family members with hypofibrinogenemia, and essentially normal clotting times, who were heterozygous for the gamma284 Gly-->Arg mutation.
Alpha1-antitrypsin (AAT) deficiency is a hereditary disorder associated with reduced AAT plasma levels, predisposing adults to pulmonary emphysema. The most common genetic AAT variants found in patients are the mildly deficient S and the severely deficient Z alleles, but several other pathogenic rare alleles have been reported. While the plasma AAT deficiency is a common trait of the disease, only a few AAT variants, including the prototypic Z AAT and some rare variants, form cytotoxic polymers in the endoplasmic reticulum of hepatocytes and predispose to liver disease. Here we report the identification of three new rare AAT variants associated to reduced plasma levels and characterize their molecular behaviour in cellular models. The variants, called Mpisa (Lys259Ile), Etaurisano (Lys368Glu) and Yorzinuovi (Pro391His), showed reduced secretion compared to control M AAT, and accumulated to different extents in the cells as ordered polymeric structures resembling those formed by the Z variant. Structural analysis of the mutations showed that they may facilitate polymerization both by loosening ‘latch’ interactions constraining the AAT reactive loop and through effects on core packing. In conclusion, the new AAT deficiency variants, besides increasing the risk of lung disease, may predispose to liver disease, particularly if associated with the common Z variant. The new mutations cluster structurally, thus defining a region of the AAT molecule critical for regulating its conformational state.
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