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Biomedical subjects

G Novelli

Publications and source records attributed to G Novelli.

At least 37 records · Page 2Linked to original sources
PubMed2001

Cloning and characterization of the gene encoding human NPL4, a protein interacting with the ubiquitin fusion-degradation protein (UFD1L).

The ubiquitin fusion-degradation gene (UFD1L) encodes the human homologue of the yeast ubiquitin fusion-degradation 1 protein, an essential component of the ubiquitin-dependent proteolytic turnover and mRNA processing. Although the UFD1L gene has been mapped in the region commonly deleted in patients with DiGeorge syndrome (DGS)/velocardiofacial syndrome (VCFS), correlation between its haploinsufficiency and the phenotype has not yet been established. The only functional data available about mammalian Ufd1p is the ability to form a complex with the rat Npl4 protein, a component of the nuclear pore complex. In this paper we report the cloning and molecular characterization of the human NPL4 gene. This gene encodes for a protein 96% homologous to the rat Npl4, and 44 and 34% homologous to the C. elegans and S. cerevisiae Npl4 gene products, respectively. Fluorescence in situ hybridization experiments on human metaphases localized the NPL4 gene on the most telomeric region of chromosome 17q. Northern blots analysis on foetal and adult human tissues revealed a major approximately 4.5 kb transcript most abundant in heart, brain, kidney and skeletal muscle. In order to test a potential relationship between nuclear transport defects and some aspect of the DGS/VCFS phenotype, we also exclude the presence of mutations in the NPL4 coding sequence in a subset of patients with DGS/VCFS and no detectable 22q11 deletion or mutations at the UFD1L locus.

Abnormalities, Multiple↗
PubMed2001

Association study of a promoter polymorphism of UFD1L gene with schizophrenia.

Schizophrenia or schizoaffective disorders are often found in patients affected by DiGeorge/velo-cardio-facial syndrome (DGS/VCFS) as a result of hemizygosity of chromosome 22q11.2. We evaluated the UFD1L gene, mapping within the DGS/VCFS region, as a potential candidate for schizophrenia susceptibility. UFD1L encodes for the ubiquitin fusion degradation 1 protein, which is expressed in the medial telencephalon during mouse development. Using case control, simplex families (trios), and functional studies, we provided evidence for association between schizophrenia and a single nucleotide functional polymorphism, -277A/G, located within the noncoding region upstream the first exon of the UFD1L gene. The results are supportive of UFD1L involvement in the neurodevelopmental origin of schizophrenia and contribute in delineating etiological and pathogenetic mechanism of the schizophrenia subtype related to 22q11.2 deletion syndrome.

Adaptor Proteins, Vesicular Transport↗
PubMed2001

Isolation and characterization of a novel gene from the DiGeorge chromosomal region that encodes for a mediator subunit.

Hemizygous deletions on chromosome 22q11.2 result in developmental disorders referred to as DiGeorge syndrome (DGS)/velocardiofacial syndrome (VCFS). We report the isolation of a novel gene, PCQAP (PC2 glutamine/Q-rich-associated protein), that maps to the DiGeorge typically deleted region and encodes a protein identified as a subunit of the large multiprotein complex PC2. PC2 belongs to the family of the human Mediator complexes, which exhibit coactivator function in RNA polymerase II transcription. Furthermore, we cloned the homologous mouse Pcqap cDNA. There is 83% amino acid identity between the human and the mouse predicted protein sequences, with 96% similarity at the amino- and carboxy-terminal ends. To assess the potential involvement of PCQAP in DGS/VCFS, its developmental expression pattern was analyzed. In situ hybridization of mouse embryos at different developmental stages revealed that Pcqap is ubiquitously expressed. However, higher expression was detected in the frontonasal region, pharyngeal arches, and limb buds. Moreover, analysis of subjects carrying a typical 22q11 deletion revealed that the human PCQAP gene was deleted in all patients. Many of the structures affected in DGS/VCFS evolve from Pcqap-expressing cells. Together with the observed haploinsufficiency of PCQAP in DGS/VCFS patients, this finding is consistent with a possible role for this novel Mediator subunit in the development of some of the structures affected in DGS/VCFS.

Amino Acid Sequence↗
PubMed2001

The mutation spectrum of the EDA gene in X-linked anhidrotic ectodermal dysplasia.

Mutations in ectodysplasin, the protein product of the EDA or ED1 gene, cause X-linked anhidrotic ectodermal dysplasia. From sixteen families we have identified thirteen mutations, of which nine were novel: a deletion of the entire exon 1, altered splicing site in intron 7 (IVS-2A-->G) and in intron 9 (IVS9+8 C-->G), deletion of 8 bp (1967-1974 nt), four missense mutations (G255C, G255D, W274G, C332Y) and nonsense mutation W274X. Previously identified and the novel mutations form four clusters: 1) at the junction of the transmembrane and extracellular domains, 2) at a putative protease recognition site, possibly affecting cleavage of ectodysplasin, 3) at the trimerizing collagen-like domain, and 4) at regions of high homology to tumor necrosis factor domains. Truncating and splice site mutations occur within the proximal two-thirds of the protein. Our data suggest the functional importance of specific ectodysplasin domains. Hum Mutat 17:349, 2001.

Alternative Splicing↗
PubMed2001

Targeted correction of a defective selectable marker gene in human epithelial cells by small DNA fragments.

A novel gene targeting strategy, small fragment homologous replacement (SFHR), has been used to correct specific genomic lesions in human epithelial cells. The frequency of targeting was estimated to be 1-10%. However, given the genomic target, the cystic fibrosis transmembrane conductance regulator (CFTR) gene, it is difficult to accurately quantify targeting frequency. As an alternative to targeting CFTR, targeted correction of a mutant selectable marker or reporter gene would be more amenable to accurate and rapid quantification of gene targeting efficiency. The present study evaluates the conditions that modulate SFHR-mediated correction of a defective Zeocin antibiotic resistance (Zeo(r)) gene that has been inactivated by a 4-bp insertion. The conditions include delivery systems, plasmid-to-fragment ratio, fragment length, and fragment strandedness (single- or double-stranded DNA). Targeting fragments comprise the wild-type Zeo(r) gene sequence and were either 410 (Zeo1) or 458 bp (Zeo3). Expression vectors containing the corrected Zeo(r) gene were isolated as episomal plasmids or were allowed to stably integrate into cultured human airway epithelial cells. Correction of the Zeo(r) gene was phenotypically defined as restoration of resistance to Zeocin in either bacteria or epithelial cell clones. Extrachromosomal gene correction was assayed using polymerase chain reaction amplification, restriction enzyme digestion, DNA sequencing, and Southern blot hybridization analysis of DNA from isolated prokaryotic and eukaryotic clones. Neither random sequence alteration in the target episomal gene nor random integration of the small fragments was detected. Targeted correction efficiencies of up to 4% were attained. These studies provide insight into parameters that can be modulated for the optimization of SFHR-mediated targeting.

Base Sequence↗
PubMed2001

Dopamine D4 receptor (DRD4) polymorphism and adaptability trait during infancy: a longitudinal study in 1- to 5-month-old neonates.

We have examined the relationship between the common dopamine D4 receptor (DRD4) exon III repeat polymorphism and infants' behavior measured with the Italian version of the Early and Revised Infancy Temperament Questionnaires (EITQ/RITQ) in 122 Italian neonates at 1 and 5 months of life, when the genetic contribution to the behavior can be more clearly assessed. Two-way (genotype x age) analysis of variance revealed a significant correlation with the temperamental subscale of adaptability [F(1, 120) = 5.26, P < 0.02]. At 1 month of life (early assessment), infants with long (L) DRD4 alleles presented significantly low scores (L 2.61 +/- 0.073; S 2.84 + 0.79; Newman-Keuls P = 0.03) in comparison with the high scores of infants with short (S) alleles (L 2.4 +/- 0.059; S 2.25 +/- 0.57). These differences were not detected at 5 months of life (late assessment), denoting a strong environmental effect at this age on the genetic background. These results confirm and extend the genetic influence of the DRD4 gene in human temperament at birth.

Adaptation, Psychological↗
PubMed2001

Three novel mutations causing a truncated protein within the RP2 gene in Italian families with X-linked retinitis pigmentosa.

X-linked retinitis pigmentosa (XLRP) results from mutations in a number of loci, including RP2 at Xp11.3, and RP3 at Xp21.1. RP2 and RP3 genes have been identified by positional cloning. RP2 mutations are found in about 10% of XLRP patients. We performed a mutational screening of RP2 gene inpatients belonging to seven unrelated families in linkage with the RP2 locus. SSCP analysis detected three conformation variants, within exon 2 and 3. Direct sequencing of exon 2, disclosed a G-->A transition at nucleotide 449 (W150X), and a G-->T transversion in position 547 (E183X). Sequence analysis of exon 3 variant revealed an insertion (853/854insG), leading to a frameshift. In this patient, we detected an additional sequence alteration (A-->G at nucleotide 848, E283G). Each mutation was co-segregating with the disease in the affected family members available for the study. These mutations are expected to introduce a stop codon within the RP2 coding sequence probably resulting in a truncated or unstable protein.

Codon, Terminator↗
PubMed2001

Mapping of a new autosomal dominant nonsyndromic hearing loss locus (DFNA30) to chromosome 15q25-26.

Hearing impairment is the most common inherited human sensory defect. Nonsyndromic Hearing Impairment (NSHI) is the most genetically heterogeneous trait known. Over 70 loci have been mapped and a total of 19 genes have been identified. We report here a novel locus (DFNA 30) for autosomal dominant NSHI that we mapped to chromosome 15q25-26 in an Italian four-generation family. The haplotype analysis has identified a critical interval of 18 cM between markers D15S151 and D15S130. This region does not overlap with DFNB16 locus but partially coincides with the otosclerosis (OTS) locus. Localisation of the locus DFNA30 is a first step towards the identification of the gene.

Chromosome Mapping↗
PubMed2001

Expression of DeltaF508 CFTR in normal mouse lung after site-specific modification of CFTR sequences by SFHR.

The development of gene targeting strategies for specific modification of genomic DNA in human somatic cells has provided a potential gene therapy for the treatment of inherited diseases. One approach, small fragment homologous replacement (SFHR), directly targets and modifies specific genomic sequences with small fragments of exogenous DNA (400-800 bp) that are homologous to genomic sequences except for the desired modification. This approach has been effective for the in vitro modification of exon 10 in the cystic fibrosis transmembrane conductance regulator (CFTR) gene in human airway epithelial cells. As another step in the development of SFHR for gene therapy, studies were carried out to target and modify specific genomic sequences in exon 10 of the mouse CFTR (mCFTR) in vivo. Small DNA fragments (783 bp), homologous to mCFTR except for a 3-bp deletion (DeltaF508) and a silent mutation which introduces a unique restriction site (KpnI), were instilled into the lungs of normal mice using four different DNA vehicles (AVE, LipofectAMINE, DDAB, SuperFect). Successful modification was determined by PCR amplification of DNA or mRNA-derived cDNA followed by KpnI digestion. The results of these studies showed that SFHR can be used as a gene therapy to introduce specific modifications into the cells of clinically affected organs and that the cells will express the new sequence.

Animals↗
PubMed2001

Fine mapping of the PSORS4 psoriasis susceptibility region on chromosome 1q21.

Psoriasis is a chronic skin disorder affecting approximately 2% of the Caucasian population. Family clustering of the disease is well established and nonparametric linkage analyzes have mapped disease susceptibility loci on chromosomes 6p (PSORS1) and 17q (PSORS2). Nonconfirmed evidence for linkage is also available for chromosomes 2q 3q, 4q (PSORS3), 8q, 16q, and 20p. We mapped an additional susceptibility locus on chromosome 1q21 (PSORS4). In this study, we have carried out a linkage disequilibrium analysis, in order to achieve a finer localization. We recruited 79 triads from continental Italy and typed them at five loci spanning the 1.6 Mb region generating the highest multipoint LOD scores in our previous linkage study. We observed significant evidence for association with D1S2346 marker (p = 0.004). Results consistent with this data were obtained by typing an independent sample that included 28 patients and 56 controls, originating from Sardinia. In fact, p values of 0.02 were observed with both D1S2346 and D1S2715 markers. We sought further confirmation of our results by typing both samples with two novel markers (140J1C and 140J1D) flanking D1S2346. Marker 140J1D generated a p value of 0.003 in the continental Italy sample where a D1S2346/140J1D haplotype was found with a higher frequency among patients' chromosomes. Altogether our data indicate that the 1q21 susceptibility gene may be localized in the genomic interval spanned by D1S2346 and 140J1D. This report provides evidence supporting the refinement of a non-HLA psoriasis susceptibility locus.

Chromosome Mapping↗
PubMed2001

A single strand conformation polymorphism-based carrier test for spinal muscular atrophy.

Spinal muscular atrophy (SMA) is an autosomal recessive disorder with a newborn prevalence of 1 in 10,000, and a carrier frequency of 1 in 40-60 individuals. The SMA locus has been mapped to chromosome 5q11.2-13. The disease is caused by a deletion of the SMN gene, often encompassing other genes and microsatellite markers. The SMN gene is present in two highly homologous copies, SMN1 and SMN2, differing at five nucleotide positions. Only homozygous SMN1 mutations cause the disease. The sequence similarity between the SMN1 and SMN2 genes can make molecular diagnosis and carrier identification difficult. We developed a sensitive and reliable molecular test for SMN1 carrier identification, by setting up a nonradioactive single strand conformation polymorphism (SSCP)-based method, which allows for the quantification of the amount of the SMN1 gene product with respect to a control gene. The assay was validated in 56 obligate (ascertained) carriers and 20 (ascertained) noncarriers. The sensitivity of the test is 96.4%, and its specificity, 98%. In addition, 6 of 7 SMA patients without homozygous deletions presented with a heterozygous deletion, suggesting a concomitant undetected point mutation on the nondeleted SMN1 allele. Therefore, the present test is effective for detecting compound hemizygote patients, for testing carriers in SMA families, and for screening for SMA heterozygotes in the general population.

Alleles↗
PubMed2001

Cloning and molecular characterization of three ubiquitin fusion degradation 1 (Ufd1) ortholog genes from Xenopus laevis, Gallus gallus and Drosophila melanogaster.

The yeast ubiquitin fusion degradation 1 (Ufd1) protein is involved in a degradation pathway for ubiquitin fused products. The human ortholog gene (UFD1-like, UFD1L) is deleted in patients affected by the DiGeorge/velocardiofacial syndromes. We report the cloning of UFD1L orthologs from Drosophila melanogaster (dufd1l), Xenopus laevis and Gallus gallus. The 1,125-bp Drosophila cDNA encodes a protein of 316 amino acids, showing 60% identity with the human and murine proteins. The identity to the G. gallus, X. laevis, C. elegans and S. cerevisiae proteins is 95%, 83%, 32%, and 36%, respectively. Northern expression data in Drosophila indicate that dufd1l is expressed through embryonic, larval and pupal development, as well as in the adult fly.

Adaptor Proteins, Vesicular Transport↗
PubMed2001

Pharmacogenetics of human androgens and prostatic diseases.

Prostate cancer (PCa) and benign prostatic hypertrophy (BPH) are two common and growing public health problems in the Western world. We review here the recent biochemical and pharmacogenetic literature related to these two prostatic disorders. We focus first on constitutional ('germline') single nucleotide polymorphism (SNPs) at the steroid 5 alpha-reductase (SRD5A2) locus, which encodes the human prostatic (or Type II) steroid 5 alpha-reductase enzyme. The investigations reviewed point to several uses of personalised medicine at the SRD5A2 locus. In addition, we report on recent identification of somatic pharmacogenetic alterations at the androgen receptor (AR) locus, which encodes the human androgen receptor, suggesting that this also may be a fruitful field of investigation, with important clinical applications. Pharmacogenomic investigation of constitutional and somatic DNA changes in human genes predisposing to cancer may lead to significant advances in chemoprevention, presymptomatic diagnosis and improved treatment of PCa.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2000

Mutations in the hepatocyte nuclear factor-1beta gene are associated with familial hypoplastic glomerulocystic kidney disease.

Familial glomerulocystic kidney disease (GCKD) is a dominantly inherited condition characterized by glomerular cysts and variable renal size and function; the molecular genetic etiology is unknown. Mutations in the gene encoding hepatocyte nuclear factor (HNF)-1beta have been associated with early-onset diabetes and nondiabetic renal disease-particularly renal cystic disease. We investigated a possible role for the HNF-1beta gene in four unrelated GCKD families and identified mutations in two families: a nonsense mutation in exon 1 (E101X) and a frameshift mutation in exon 2 (P159fsdelT). The family members with HNF-1beta gene mutations had hypoplastic GCKD and early-onset diabetes or impaired glucose tolerance. We conclude that there is genetic heterogeneity in familial GCKD and that the hypoplastic subtype is a part of the clinical spectrum of the renal cysts and diabetes syndrome that is associated with HNF-1beta mutations.

Adolescent↗
PubMed2000

Mapping a dominant form of multinodular goiter to chromosome Xp22.

Multinodular goiter (MNG) is a common disorder characterized by a nodular enlargement of the thyroid gland and occurring with a female&rcolon;male ratio of 5&rcolon;1. This article reports the analysis of an Italian three-generation pedigree MNG, including 10 affected females and 2 affected males. After linkage to candidate regions previously implicated in various forms of goiter was excluded, a novel MNG locus was searched. Because no male-to-male transmission was present in the study pedigree, an X-linked autosomal dominant pattern of inheritance was hypothesized. Therefore, 18 markers spaced at 10-cM intervals on the X chromosome were examined. A significant LOD score was observed in the Xp22 region, where marker DXS1226 generated a maximum LOD score of 4.73 at a recombination fraction of 0. Analysis of six flanking microsatellites confirmed these data, and haplotype inspection delimited a 9.6-cM interval lying between DXS1052 and DXS8039.

Chromosome Mapping↗