A subset of genetic susceptibility variants for colorectal cancer also has prognostic value.

We investigated the possible influence of 86 single-nucleotide polymorphisms (SNPs), known to associate with the risk of colorectal cancer (CRC), on overall survival and time to recurrence (TTR) in 733 Italian CRC patients followed up for up to 84 months after surgery. In the Cox multivariate analysis, adjusted for gender, age, pathological stage and adjuvant chemotherapy (yes/no), the risk of death significantly increased by rare allele count (P<0.05) for rs1801133 (MTHFR), rs4939827 (SMAD7), rs2306283 (SLCO1B1) and rs12898159 (BMP4), whereas for rs736775 (GPX3) the opposite was observed. Two additional SNPs associated with TTR, namely rs16892766 (downstream of EIF3H) and rs10749971 (COLCA2). Our findings show that some genetic variants previously found to associate with CRC risk are also associated with survival after treatment. The identification of alleles defining subgroups of patients with worse clinical outcome may have application in developing pharmacogenetic strategies aimed at personalizing CRC treatment.

Mutation identification of Fabry disease in families with other lysosomal storage disorders.

Fabry disease (FD) is an X-linked lysosomal storage disorder (LSD) caused by the deficiency of the enzyme α-galactosidase. It exhibits a wide clinical spectrum that may lead to a delayed or even missed diagnosis and the real incidence can be underestimated. We report the cases of two unrelated Italian families in whom FD was incidentally diagnosed in two females. In both families, the risk for other lysosomal disorders was known from other members affected by fucosidosis or mucopolysaccharidosis I Hurler/Scheie. Some subjects were simultaneously heterozygous for Fabry and the other lysosomal deficiency. Our study shows that the risk for more than one LSDs can occur in a family pedigree. The diagnosis of Fabry in female probands represents a diagnostic challenge, as symptoms and signs can be variably present because of the random X-chromosome inactivation.

Novel mutations of the ferroportin gene (SLC40A1): analysis of 56 consecutive patients with unexplained iron overload.

The aim of this study was to search for SLC40A1 mutations in iron overloaded patients, which tested negative for HFE mutations and other iron-related genes. After a careful differential diagnosis, we selected 56 patients with unexplained iron overload whose phenotype could suggest the ferroportin disease. Iron overload was assessed by liver biopsy or by superconducting quantum interference device. SLC40A1 exons and intron-exon boundaries were amplified by polymerase chain reaction and sequenced. We also evaluated the presence of the insulin-resistance hepatic iron overload and of non-alcoholic fatty liver disease. Iron status was assessed in 44 families. We identified two novel mutations (D157N and V72F) at the heterozygous state in two probands. Phenotype heterogeneity was observed in both families, suggesting variable penetrance and expression. Including the two affected ones, 25 of the 44 families (57%) available for the iron study had one or more relatives with increased serum iron indices. Our findings not only suggest that the presence of major alterations of serum iron parameters in probands' relatives is a main criteria to improve the power of the genetic testing for ferroportin disease but also indicate that a number of patients exists in which the etiology of iron overload remains still undefined.

Hyperferritinaemia without iron overload: pathogenic and therapeutic implications.

It is not unusual to meet increased levels of ferritinaemia in patients apparently healthy. Among other causes of hyperferritinaemia, recently was described the Hereditary Hyperferritinemia Cataract Syndrome, a genetic condition characterized by increased serum ferritin values without iron overload and bilateral nuclear cataract, both of early onset. It has been demonstrated that single or double point mutations or deletions in the stem-loop structure of the iron regulatory element (I.R.E.) located in the 5 untranslated regions of the ferritin L-subunit gene (19q13.1) are responsible for the upregulation of ferritin. This overexpression only for the L-chain gives rise to typical piles in several tissues. When this altered ferritin accumulates in lens it causes bilateral nuclear cataracts, that is the peculiar sign of this syndrome. It is essential to differentiate true iron overload from Hereditary Hyperferritinaemia Cataract Syndrome (H.H.C.S.), because these patients rapidly develop iron deficient anaemia when venosectioned. Here we describe a case report about a 40 years old healthy female blood donor who presented isolated hyperferritinaemia without iron overload, in the absence of concomitant pathologies. Anamnestic, biochemical, instrumental and clinical investigations led us to diagnose H.H.C.S., a pathology first described in 1995. From 1995 to date about 40 cases concerning patients showing the characteristics of this syndrome from Europe, USA, and Australia were described. Biochemical, genetical and clinical investigations led finally to understand every matter of this pathology, providing conclusive and exhaustive explanations.

N-Terminal domain of HTLV-I integrase. Complexation and conformational studies of the zinc finger.

The HTLV-I integrase N-terminal domain [50-residue peptide (IN50)], and a 35-residue truncated peptide formed by residues 9-43 (IN35) have been synthesized by solid-phase peptide synthesis. Formation of the 50-residue zinc finger type structure through a HHCC motif has been proved by UV-visible absorption spectroscopy. Its stability was demonstrated by an original method using RP-HPLC. Similar experiments performed on the 35-residue peptide showed that the truncation does not prevent zinc complex formation but rather that it significantly influences its stability. As evidenced by CD spectroscopy, the 50-residue zinc finger is unordered in aqueous solution but adopts a partially helical conformation when trifluoroethanol is added. These results are in agreement with our secondary structure predictions and demonstrate that the HTLV-I integrase N-terminal domain is likely to be composed of an helical region (residues 28-42) and a beta-strand (residues 20-23), associated with a HHCC zinc-binding motif. Size-exclusion chromatography showed that the structured zinc finger dimerizes through the helical region.

Human T-lymphotrophic virus type I nucleocapsid protein NCp15: structural study and stability of the N-terminal zinc-finger.

An 18-residue peptide, corresponding to the minimum sequence of the N-terminal zinc-finger domain in the nucleocapsid of human T-lymphotrophic virus type I, was synthesized by a solid-phase method and fully characterized. Its ability to complex metal ions (Co(2+) and Zn(2+)) was clearly established by UV-visible spectroscopy and MS. The stability of these complexes was investigated by an original method with HPLC chromatography. Our results show that, even in the presence of air, the Zn(2+) complex is highly stable. In contrast, the Co(2+) complex undergoes a relatively fast degradation due to an intramolecular oxidation leading to the formation of a disulphide bridge between two cysteine residues. The (1)H-NMR analysis indicates that Zn(2+) binds to the Ndelta atom of the histidine residue rather than to the Nepsilon atom. Two-dimensional NMR techniques were used to determine the solution structure of the zinc-finger, illustrated by the existence of turns in the overall conformation.