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Biomedical subjects

G Novelli

Publications and source records attributed to G Novelli.

At least 181 records · Page 10Linked to original sources

Forensic applications of molecular genetic analysis: an Italian collaborative study on paternity testing by the determination of variable number of tandem repeat DNA polymorphisms.

Several variable number of tandem repeat (VNTR) DNA polymorphisms detecting different loci (YNH24/MspI or TaqI, CMM101/MspI or MLJ14/MspI, EFD64.2/RsaI or HinfI, YNZ22/TaqI, AW101/EcoRI, EKMDA2.1/PvuII and 3'-HVR/PvuII) were used in the analysis of 27 cases of disputed paternity in the Italian population. Fourteen exclusions and 17 attributions were performed. The results were compared with those obtained with immunohematologic analyses. Four exclusions and 2 attributions were made possible only by the combined use of several DNA polymorphisms, as the analyses of red-blood-cell antigens and isoenzymes, serum proteins and HLA group determinants were inconclusive. With the DNA test, 10 exclusions and 15 attributions were confirmed, with increased overall probability. In conclusion, VNTR polymorphisms were more informative, accurate and sensitive than the immunohematologic tests. Therefore, DNA analysis is the method of choice for testing genetic relationships.

Alleles↗

Autosomal dominant polycystic kidney disease: a linkage evaluation of heterogeneity in Italy. Italian Collaborative Group on Polycystic Kidney Disease.

A survey of 29 families with Adult Polycystic Kidney Disease (ADPKD) was performed to evaluate the genetic heterogeneity of the disease in Italy. The approach was through the linkage between the disease and 2 polymorphic DNA fragments as detected by the probes 3'HVR and 24.1. Linkage between the polymorphic markers and the disease was confirmed, with the following lod scores: between 3'HVR and ADPKD1 = 12.974 at theta = 0.02; between 24.1 and ADPKD = 1.716 at theta = 0.07; between 3'HVR and 24.1 = 2.738 at theta = 0.09. No evidence of significant genetic heterogeneity in the examined Italian regions was detected.

Genes, Dominant↗

Characterization of deletions in the dystrophin gene giving mild phenotypes.

We have characterized deletions of the dystrophin gene in patients suffering from relatively mild muscular dystrophy. Our data show that most of the Becker muscular dystrophy (BMD) patients have intragenic deletions which leave the protein reading frame in phase. Remarkably, large deletions of the region corresponding to the central triple helical repeats in the protein can result in an exceptionally mild phenotype. Three brothers suffering from BMD, glycerol kinase deficiency, and adrenal hypoplasia possess a deletion at the 3' end of the gene. They also display developmental delay. Thus the 3' processing of the gene must be necessary for the correct function of the dystrophin molecule.

Adrenal Glands↗

A 45,X male with molecular evidence of a translocation of Y euchromatin onto chromosome 1.

A 45,X complement was found in lymphocyte and fibroblast cultures of a male infant with severe growth and mental retardation and mild dysmorphism. Lymphocyte DNA from this patient was found to contain Yp chromosome sequences. In situ hybridization (ISH) with the 50f2 probe led to a clear assignment of euchromatic material on the short arm of chromosome 1. This observation and others from the literature argue in favour of the conclusion that all 45,X males are probably either the result of undetected mosaicism or are carriers of Y translocated material.

Child, Preschool↗

Polymorphic DNA haplotypes and delta F508 deletion in 212 Italian CF families.

Haplotype data based on the DNA markers closely linked to the cystic fibrosis (CF) gene have been used to correlate the presence of the 3 bp specific deletion (delta F508) in 424 CF chromosomes from 212 Italian CF families. The distribution and the frequency of the F508 deletion on CF chromosomes in our sample suggests the presence of at least a second mutation in the same ancestral haplotype.

Chromosome Deletion↗

The genotype of a new linked DNA marker, MP6d-9, is related to the clinical course of cystic fibrosis.

The clinical symptoms of a cohort of cystic fibrosis patients were related to their genotypes using RFLPs shown with MspI and the closely linked DNA marker MP6d-9. In the majority of CF chromosomes, the restriction site for MspI was present, and the genotype 2/2 was found most often in patients who were severely affected by the disease. The genotype 1/2 was significantly over-represented in patients with very mild clinical manifestations, including pancreatic sufficiency, absence of meconium ileus, and absence of Pseudomonas colonisation. When pancreatic dysfunction was present, the 1/2 genotype was associated with a mild form, while the 2/2 genotype was found in patients with severe insufficiency. None of our patients had the 1/1 genotype. These results indicate that the newly isolated MP6d-9 marker correlates with some important symptoms of cystic fibrosis.

Cystic Fibrosis↗

Regional distribution of cystic fibrosis linked DNA haplotypes in Italy, a collaborative study.

In view of the reported variations of cystic fibrosis (CF) associated haplotypes among populations, a detailed analysis of the distribution of two tightly linked DNA markers (Xv-2c and KM.19) in 18 Italian regions was performed. Haplotypes were determined for 405 CF chromosomes carrying the mutation, and showed significant heterogeneity between the North, Center, and South of Italy and the island of Sardinia. KM.19/PstI Restriction Fragment Length Polymorphism (RFLP) showed significant heterogeneity in these four areas, and was statistically correlated with the geographic distribution of the disease, while Xv-2c/TaqI polymorphism, like the haplotypes of normal chromosomes, was more uniformly distributed over the same four areas. Correlation coefficients between the markers and the mutation have been used to obtain additional indications on the physical distance between the markers and the fibrosis locus.

Cystic Fibrosis↗

Laron dwarfism and mutations of the growth hormone-receptor gene.

Laron dwarfism is associated with resistance to growth hormone (GH). To investigate its genetic basis, we used genetic linkage to test whether the disorder results from a defect in the gene for the human GH receptor. Denaturing gradient gel electrophoresis and sequencing of specific GH-receptor-gene fragments allowed us to characterize specific intragenic DNA markers in 35 control subjects of Mediterranean descent, for use in linkage studies. In two Mediterranean families in which the parents were consanguineous and some of the children had Laron dwarfism, the disease trait and DNA polymorphisms were inherited together. Moreover, an analysis of the GH-receptor-gene RNA transcripts in lymphocytes from one of these families allowed us to identify a thymidine-to-cytosine substitution that generated a serine in place of a phenylalanine at position 96 in the extracellular coding domain of the mature protein. This defect probably affects the receptor adversely and is probably responsible for the lack of plasma GH-binding activity in the patients. This mutation was not found in the GH-receptor genomic sequences of seven unrelated subjects with Laron dwarfism who belonged to different population groups. An analysis of the GH-receptor markers in these patients indicated that different gene frameworks (polymorphic sites within the single gene) were associated with the mutant alleles. We conclude that Laron dwarfism is due to abnormalities in the gene for GH receptor, which may differ from family to family.

Base Sequence↗

First-trimester prenatal diagnosis of cystic fibrosis using the polymerase chain reaction: report of eight cases.

Eight pregnancies at risk for cystic fibrosis have been monitored by first-trimester prenatal diagnosis with DNA amplification analysis. The polymerase chain reaction (PCR) was used in all cases to amplify the region detected by KM19. In two cases, the region detected by CS.7, another DNA probe tightly linked to the CF locus, was also examined. The results of the PCR determinations were confirmed using the Southern blotting procedure, by segregation analysis of restriction fragment length polymorphisms (RFLPs) relative to XV-2c, J3.11, metH, metD, and KM19 probes.

Blotting, Southern↗

Prenatal diagnosis of adult polycystic kidney disease with DNA markers on chromosome 16 and the genetic heterogeneity problem.

A prenatal diagnosis of adult polycystic kidney disease by DNA testing is reported. Evidence showing a linkage between the disease and the 3'HVR and 24.1 restriction fragment length polymorphisms (RFLPs) on chromosome 16 was obtained in the proband's family by linkage analysis of data and homogeneity testing with Italian families of the linked type. Fetal genotype prediction based on both flanking markers was confirmed by histological and ultrastructural findings in fetal kidneys.

Adult↗

Linkage disequilibrium for DNA haplotypes near the cystic fibrosis locus in two south European populations.

Three polymorphic DNA marker loci (INT1L1, D7S23 and D7S399) map to a chromosomal region that is very close to the cystic fibrosis (CF) locus in terms of genetic distance. These marker loci have been used to analyse the linkage disequilibrium in 137 CF families from two South European countries (Italy and Spain). The markers can be analysed for differences in linkage disequilibrium more easily in these populations than in North Europeans, in whom the disequilibrium between the allelic systems defined by the probes and CF is much greater and on a "plateau" through the genetic region. The different levels of disequilibrium found in the studied populations suggest that D7S399 and D7S23 are both closer to CF than INT1L1, and provide additional information on the origins and homogeneity of the CF defect.

Cystic Fibrosis↗

Identification of 4 ataxia telangiectasia cell lines hypersensitive to gamma-irradiation but not to hydrogen peroxide.

The effect of hydrogen peroxide on the rate of semi-conservative DNA synthesis in ataxia telangiectasia (AT) and normal human lymphoblastoid cells was investigated. The rate of DNA synthesis in AT cells was not depressed to a lesser extent than in normal cells, as might have been expected since H2O2 is a radiomimetic agent. On the contrary, 4 AT cell lines displayed a higher sensitivity to the inhibitory effect of H2O2 on DNA synthesis than 2 normal cell lines. Comparable levels of cytotoxicity were detected in cell viability studies. Furthermore, neither the level of DNA breakage produced by H2O2, nor the rate of repair of these lesions was significantly different in normal and AT cells. Together, these results indicate that the AT cell lines utilized in this study are not hypersensitive to the oxidant. It is suggested that H2O2 may not induce lethality via the direct action of the hydroxyl radical (OH.).

Ataxia Telangiectasia↗