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M Frontali

Publications and source records attributed to M Frontali.

At least 55 records · Page 3Linked to original sources
PubMed1992

DNA markers in diagnosis of adult dominant polycystic kidney disease.

We report the results of a biological and molecular study carried out on 11 Italian families, with a total of 111 individuals in which adult dominant polycystic kidney disease segregates. A restriction fragment length polymorphism analysis was performed. Two families have shown a genetic heterogeneity even if not phenotypically different from the other ones: they resulted unlinked to 16p markers. A prenatal diagnosis has been performed in a family of the linked type.

DNA↗
PubMed1992

Neurofibromatosis type 2 appears to be a genetically homogeneous disease.

Neurofibromatosis type 2 (NF2) is an autosomal dominant syndrome characterized by the development of vestibular schwannomas and other tumors of the nervous system, including cranial and spinal meningiomas, schwannomas, and ependymomas. The presence of bilateral vestibular schwannomas is sufficient for the diagnosis. Skin manifestations are less common than in neurofibromatosis type 1 (NF1; von Recklinghausen disease). The apparent clinical distinction between NF1 and NF2 has been confirmed at the level of the gene locus by linkage studies; the gene for NF1 maps to chromosome 17, whereas the gene for NF2 has been assigned (in a single family) to chromosome 22. To increase the precision of the genetic mapping of NF2 and to determine whether additional susceptibility loci exist, we have performed linkage analysis on 12 families with NF2 by using four polymorphic markers from chromosome 22 and a marker at the NF1 locus on chromosome 17. Our results confirm the assignment of the gene for NF2 to chromosome 22 and do not support the hypothesis of genetic heterogeneity. We believe that chromosome 22 markers can now be used for presymptomatic diagnosis in selected families. The NF2 gene is tightly linked to the D22S32 locus (maximum lod score 4.12; recombination fraction 0). A CA-repeat polymorphism at the CRYB2 locus was the most informative marker in our families (lod score 5.99), but because the observed recombination fraction between NF2 and CRYB2 was 10 cM, predictions using this marker will need to be interpreted with caution.

Chromosomes, Human, Pair 17↗
PubMed1991

Non-random association between DNA markers and Huntington disease locus in the Italian population.

A group of Huntington disease (HD) families of Italian ancestry was analyzed for 11 RFLPs from genetic loci mapped in 4p16 and genetically linked to the HD gene. We found a statistically significant difference of allele distributions in HD vs normal chromosomes for loci D4S10, D4S127, and D4S43. This observation increases the number of loci in linkage disequilibrium with HD. However, the amount of disequilibrium does not allow either a finer localization of the HD gene or a substantial improvement in risk calculations.

Alleles↗
PubMed1991

Spinocerebellar ataxia (SCA1) in two large Italian kindreds: evidence in favour of a locus position distal to GLO1 and the HLA cluster.

Two large Italian pedigrees with HLA-linked spinocerebellar ataxia (SCA1) were typed for HLA-A, -B and -DR as well as for markers either distal (F13A, D6S8) or proximal (D6S29, GLO1) to HLA. Pairwise linkage analyses of SCA1 vs. HLA-A, -B, and -DR showed peak lodscores of 5.3, 5.6 and 3.3 respectively at 7% recombination. Negative lodscores significantly excluded linkage with F13A at less than 5% and with GLO1 at less than 10%. The lodscores with D6S8 and D6S29 had only low peaks. Recombination events in the two pedigrees and the estimated genetic distances of SCA1 from GLO1 and HLA favour the hypothesis of a SCA1 location distal to both of them. An order cen-GLO1-HLA-SCA1-tel appears therefore most likely with present data. These results are discussed in relation to previous reports placing SCA1 distal to HLA in two families and

Adult↗
PubMed1990

Epidemiological and linkage studies on Huntington's disease in Italy.

The results of an epidemiological survey on Huntington's disease in the Lazio Region, Central Italy, and of linkage studies in a subset of families are reported. From a total of 99 ascertained families and 491 patients, a prevalence of 25.6 X 10(-6) was obtained, with distributions of age at onset and age at death similar to those described in the literature. No relationship with the sex of the transmitting parent was observed. Analysis of 10 chromosome 4 restriction fragment length polymorphisms in 11 families showed consistent linkage between the genetic loci D4S10, D4S43 and D4S95, and the disease. A recombination rate of 0.08 for D4S10 markers was obtained in this sample. Allelic frequencies of DNA markers in the general population are also reported.

Adolescent↗
PubMed1990

On the estimation of the age at onset distribution in Huntington's chorea using the EM algorithm.

Huntington's chorea is a late onset disease of the nervous system whose mode of inheritance conforms to the autosomal dominant model. The present paper shows how the problem of estimating the distribution of age at onset of the disease can be dealt with as an incomplete data problem via the EM algorithm, both in the parametric and non-parametric setting. In this way it is possible to take into account not only the heterozygotes in the population under study who are manifestly affected, but also those who are apparently unaffected. The estimation of the distribution of age at onset of the disease is required for estimating the posterior probability of heterozygosity of the individual at risk using Bayes' theorem. The proposed approach was applied to data derived from a survey carried out on the population of Latium, Italy.

Adolescent↗
PubMed1989

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↗
PubMed1989

Multifactorial inheritance and recurrence risks of multiple sclerosis in Italian patients.

This study is based on 166 patients with definite multiple sclerosis (MS) residing in different Italian regions and on 332 parents and 326 siblings. Seven patients had a first-degree relative with a definite diagnosis. The comparison with a population age-matched for specific frequency of MS showed an increase of the disease among relatives. The increase in MS frequency among sibs is compared with that expected under an autosomal dominant, autosomal recessive or multifactorial model. The multifactorial hypothesis appears to better fit the data. The heritability index is calculated for each combination of relative and affected patient sex and compared with estimates of other European and American countries. The recurrence risk rates for male and female relatives have been computed for the more frequent family situations. Our results support the hypothesis of a multifactorial model of inheritance and provide risk figures to be used in genetic counseling.

Adult↗
PubMed1985

Osteoporosis-pseudoglioma syndrome: report of three affected sibs and an overview.

We report on a sibship with one brother and two MZ twin sisters affected with osteoporosis-pseudoglioma syndrome. An analysis of the present and literature data showed that vitreoretinal dysplasia or phthisis bulbi and X-ray evidence of osteoporosis must be considered minimal diagnostic criteria. Mental retardation, ligamentous laxity, and other reported anomalies are highly variable manifestations in the syndrome. Segregation analysis confirmed autosomal recessive transmission. The geographic origin of reported families suggests a higher gene frequency in Mediterranean countries.

Adult↗
PubMed1983

Mating between two balanced translocation carriers in two unrelated families.

Partial trisomy 9p and a 13/14 translocation occurred in the daughter of a t(5;9)(p15;p12) mother and a t(13;14)(p11;q11) father. Two additional offspring displayed a normal karyotype and a translocation trisomy 13 respectively. Two first cousins, selected for chromosome analysis because of a spontaneous abortion, were found to have an identical translocation t(14;21)(p11;q11). Their second pregnancy was monitored by midtrimester amniocentesis and disclosed a balanced fetus. The different zygotic chromosome constitutions and the counselling problems in the marriages between two balanced translocation carriers are discussed.

Adult↗