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Biomedical subjects

L Dalprà

Publications and source records attributed to L Dalprà.

At least 37 records · Page 2Linked to original sources
PubMed1999

SER252PHE and 776INS3 mutations in the CHRNA4 gene are rare in the Italian ADNFLE population.

41 patients (19 sporadic and 22 familial) affected by autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) were analyzed for the presence of two mutations (Ser252Phe, 776ins3) in the CHRNA4 gene, reported to be associated with this disease. Electroclinical findings of sporadic forms were indistinguishable from familial ones. In none of the patients, these mutations were found by dot blot analysis with allele specific oligonucleotides. These data, obtained on the largest group so far studied, suggest the rarity of the reported mutations.

Adolescent↗
PubMed1999

First cytogenetic study of a recurrent familial chordoma of the clivus.

Two recurrences of a familial clivus chordoma, arisen from a patient who developed the primary tumor at age of 8 years, were investigated by cytogenetic and the fluorescence in situ hybridization (FISH) approach. Of the patient's 3 daughters, 2 developed, respectively, a clivus chordoma and an astrocytoma in infancy, a familial aggregation highly suggestive of a genetic background. After a 31-year hiatus, 2 tumor recurrences, developed over 17 months, were removed surgically. Both were hypo- or nearly diploid, and had a pronounced karyotypic heterogeneity with clonal and non-clonal rearrangements affecting several chromosomes. The same rearrangement, a dic(1;9)(p36.1;p21), was shared in both tumor specimens and, in 90% of the cells, chromosome 1p appeared to be involved in unbalanced translocations with different chromosomes, leading to variable losses of 1p. Previous cytogenetic data concerning chordoma are limited to 10 sporadic tumors with an abnormal karyotype; although no tumor-specific rearrangements have been identified, chromosome 1p appears to be involved frequently.

Adolescent↗
PubMed1999

The idiopathic forms of premature menopause and early menopause show the same genetic pattern.

Genetic factors may influence the timing of menopause. Premature ovarian failure (POF) has recently been identified as a genetic entity, but no genetic data are available on early menopause (EM). We investigated 36 patients with EM (age of menopause between 40 and 45 years of age) using cytogenetic and pedigree analysis. In 30 patients of this study the EM was idiopathic and 15 subjects (50%) had a familial condition of EM or POF. Pedigree analysis revealed a dominant pattern of inheritance of EM through maternal or paternal relatives. Our data reveal that POF and EM patients show the same genetic features and we postulate that these conditions may be a variable expression of the same genetic disease.

Adult↗
PubMed1998

Chromosomal instability in fibroblasts and mesenchymal tumors from 2 sibs with Rothmund-Thomson syndrome.

Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive genodermatosis associated with increased risk of mesenchymal tumors. The putative gene has been provisionally assigned to chromosome 8. Using a cytogenetic-molecular approach, we studied lymphocytes, fibroblasts, osteosarcoma (OS) and malignant fibrous histiocytoma (MFH) from 2 affected fraternal twins, looking for constitutive markers of chromosome instability and tumor chromosomal changes which might reflect the common genetic background. The rate of spontaneous chromosome aberrations was not increased in lymphocytes. Conversely, karyotyping of primary fibroblasts from one sib evidenced chromosome breaks and both numerical and structural chromosome changes in 24% and 17% of the metaphases respectively. FISH of a 8q21.3 cosmid allowed us to detect trisomy of the target region on 7% of fibroblast nuclei from both sibs, 47% and 12% of OS and MFH cells. Pronounced chromosomal instability and clonal rearrangements leading to different chromosome-8 derivatives were detected in both tumors. CGH experiments showed multiple gains/losses, among which del(6q), also revealed by cytogenetics, and 7p gain were common, whereas 8q amplification was present only in OS. Chromosomal instability, observed in fibroblasts from the RTS patients studied, accounts for the increased risk of mesenchymal tumors in these patients.

Adolescent↗
PubMed1998

Molecular characterization of FRAXE-positive subjects with mental impairement in two unrelated Italian families.

The FRAXE fragile site, 600 Kb distal to the more common FRAXA, has been reported to be expressed in subjects with mild nonsyndromal mental retardation. Amplification of more than 200 GCC repeats associated with methylation of the adjacent CpG island at Xq28 is responsible for FRAXE fragility. We describe two unrelated, mentally retarded males identified during a screening for fragile X syndrome. Both index cases underwent FRAXE molecular analysis, following cytogenetic expression of the fra X site and negative FRAXA test. In family 1, we were able to investigate other 13 subjects over three generations, identifying two additional FRAXE-positive males, one with a fully mutated allele and one with a mosaic genotype. Detailed evaluation of physical traits and psychometric tests was performed on three retarded males from family 1 and the propositus from family 2. All of them were found to lack a definite phenotype, and showed different degrees of mental retardation. Slight mental retardation was evident in the mosaic male, suggesting that methylation might be an important determinant of mental impairment.

Adolescent↗
PubMed1998

Autosomal dominant nocturnal frontal lobe epilepsy. A video-polysomnographic and genetic appraisal of 40 patients and delineation of the epileptic syndrome.

A number of clinical and aetiological studies have been performed, during the last 30 years, on patients with abnormal nocturnal motor and behavioural phenomena. The aetiological conclusions of these studies were often conflicting, suggesting either an epileptic or a non-epileptic origin. Among the clinical characteristics of these patients, the familial clustering was one thoroughly accepted. A nocturnal familial form of frontal lobe epilepsy (autosomal dominant nocturnal frontal lobe epilepsy, ADNFLE), often misdiagnosed as parasomnia, has been recently described in some families. In one large Australian kindred, a missense mutation in the second transmembrane domain of the neuronal nicotinic acetylcholine receptor alpha 4 subunit (CHRNA4) gene, located on chromosome 20 q13.2-13.3, has been reported to be associated with nocturnal frontal lobe epilepsy. We performed an extensive clinical and video-polysomnographic study in 40 patients complaining of repeated abnormal nocturnal motor and/or behavioural phenomena, from 30 unrelated Italian families. Thirty-eight patients had an electroclinical picture strongly suggesting the diagnosis of ADNFLE. They had a wide clinical spectrum, ranging from nocturnal enuresis to sleep-related violent behaviour, thus including all the main features of the so-called 'typical' parasomnias. The video-polysomnographic recording confirmed the wide spectrum of abnormal manifestations, including sudden awakenings with dystonic/ dyskinetic movements (in 42.1% of patients), complex behaviours (13.2%) and sleep-related violent behaviour (5.3%). The EEG findings showed ictal epileptiform abnormalities predominantly over frontal areas in 31.6% of patients. In another 47.4% of patients the EEG showed ictal rhythmic slow activity over anterior areas. Only 18.4% of the patients had already received a correct diagnosis of epilepsy. In 73.3% of the patients treated with anti-epileptic drugs the seizures were readily controlled. Pedigree analysis on 28 of the families was consistent with autosomal dominant transmission with reduced penetrance (81%). DNAs from 20 representative affected individuals were sequenced in order to check for the presence of the missense mutation in the CHRNA4 gene found in the Australian kindred affected by ADNFLE. Nucleotide sequence analysis did not reveal the presence of this mutation, but it did confirm the presence of two other base substitutions, not leading to amino acid changes. These two intragenic polymorphisms, together with a closely linked restriction fragment length polymorphism at the D20S20 locus, have been used for linkage analysis of ADNFLE to the terminal region of the long arm of chromosome 20 in five compliant families. The results allowed us to exclude linkage of ADNFLE to this chromosomal region in these families, thus confirming the locus heterogeneity of the disorder. Large and full video-polysomnographical studies are of the utmost importance in order to clarify the real prevalence of both nocturnal frontal lobe epilepsy and parasomnias, and to provide a correct therapy.

Adult↗
PubMed1998

Inheritance in idiopathic premature ovarian failure: analysis of 71 cases.

Premature ovarian failure is defined as cessation of ovarian function under the age of 40 years and affects approximately 1% of women in the general population. The aetiology of this disorder is still unknown in most cases. Although there have been some reports of familial premature ovarian failure, very little is known about the incidence and inheritance pattern of its idiopathic form. The aims of this study were to investigate the incidence and inheritance pattern of familial premature ovarian failure in a homogeneous group of patients with premature idiopathic menopause and to identify possible clinical differences between patients with the familial and the sporadic form of premature ovarian failure. A total of 71 women were recruited into the study. Clinical assessments and genetic counselling showed that 22 (31%) patients had familial premature ovarian failure, this high incidence strongly suggesting that the disorder is a recognizable heritable entity. There was a statistically significant (P < 0.05) difference in the median age of precocious menopause in patients with sporadic and familial premature ovarian failure (31.0 and 37.5 years of age in the two groups, respectively). Pedigree analysis strongly suggests the existence of a familial pattern of premature ovarian failure with a dominant maternal and/or paternal transmission and incomplete penetrance. In the presence of familial history of premature ovarian failure, reproductive counselling is recommended.

Adolescent↗
PubMed1997

Genotype-phenotype correlation in two sets of monozygotic twins with Williams syndrome.

We report on two sets of monozygotic (MZ) twins with Williams syndrome (WS), following the 6 pairs already reported in the literature. We have confirmed monozygosity of both pairs of twins by DNA microsatellite analysis and the clinical diagnosis by fluorescence in situ hybridization using a WS-specific probe. Analysis of the concordance of different clinical signs between members of each pair of twins benefitted from a lengthy clinical follow-up, from 24 months to 7 years in one pair, and from the age of 15 years with reevaluation after 2 years in the other pair. Most clinical signs were concordant in the twins of each pair, with differences present at younger ages, mainly minor facial anomalies, being attenuated with time. Developmental delay was substantially concordant, but the degree differed slightly between twins in each pair. Inguinal hernia was present in a single twin in pair 1. Facial anomalies and other signs attributable to connective tissue abnormalities were also displayed by only one twin in both sets, suggesting that the WS genotype has only a predisposing role in the development of these signs.

Adolescent↗
PubMed1997

Age-related increase of baseline frequencies of sister chromatid exchanges, chromosome aberrations, and micronuclei in human lymphocytes.

Intra- and interindividual variations of baseline frequencies of cytogenetic end points in lymphocytes of human populations have been reported by various authors. Personal characteristics seem to account for a significant proportion of this variability. Several studies investigating the role of age as a confounding factor in cytogenetic biomonitoring found an age-related increase of micronucleus (MN) frequency, whereas contradictory results were reported for chromosomal aberrations (CAs) and sister chromatid exchanges (SCEs). We have quantitatively evaluated the effect of age on SCE, CA, and MN through the analysis of a population sample that included data from several biomonitoring studies performed over the last few decades in 12 Italian laboratories. The large size of the data set, i.e., more than 2000 tests for each end point, allowed us to estimate the independent effect of age, taking into account other covariates, such as sex, smoking habits, occupational exposure, and inter- and intralaboratory variability. A greater frequency of the mean standardized values by increasing of age was observed for all of the end points. A leveling off was evident in the last age classes in the trend of MN frequencies. Frequency ratios (FRs), which express the increase of the cytogenetic damage with respect to the first age classes, i.e., 1-19 years, were estimated using Poisson regression analysis after adjustment for the potential confounding factors and confirmed the increasing trend by age class for all three end points. The most dramatic increase was observed for MN, with a FR that approaches the value of 2 at the age class 50-59 (FR, 1.97; 95% confidence interval, 1.43-2.71) and remains substantially unchanged thereafter. The trend of FRs for CA is more homogeneous, with a constant rise even in the older classes, whereas the frequency of SCE increases with age to a lesser extent, reaching a plateau in the age class 40-49 and the maximum value of FR in the age class over 70 (FR, 1.14; 95% confidence interval, 1.07-1.23). In conclusion, our results point to an age-related increase of the chromosome damage in lymphocytes and emphasize the need to take into account the potential confounding effect of this variable in the design of biomonitoring studies based on chromosome damage.

Adolescent↗
PubMed1996

Characterization of a cytogenetic 17q11.2 deletion in an NF1 patient with a contiguous gene syndrome.

We report on a rare patient screened as a putative carrier of a contiguous gene syndrome on the basis of a complex phenotype characterized by sporadic neurofibromatosis type 1 (NF1), dysmorphism, mental retardation and severe skeletal anomalies. A cytogenetically visible 17q11.2 deletion was detected in the patient's karyotype by high-resolution banding and confirmed by fluorescence in situ hybridization with yeast artificial chromosomes targeting the NF1 region. Analysis of the segregation from parents to proband of 13 polymorphic DNA markers, either contiguous or contained within the NF1 gene, showed that the patient is hemizygous at sites within the NF1 gene-the AAAT-Alu repeat in the 5' region of intron 27b, the CA/GT microsatellite in the 3' region of intron 27b, and the CA/GT microsatellite in intron 38- and at the extragenic D17S798 locus, distal to the 3' end of NF1. The patient may be an important resource in the identification of genes downstream of NF1 that may contribute to some of his extra-NF1 clinical signs.

Adult↗
PubMed1996

Further delineation of 7p trisomy. Case report and review of literature.

The authors report on the 7th case of "de novo" 7p trisomy [46,XY,dup (7) (p15-pter)], followed during 6-and-a-half years. Through literature review, examination of pictures and dermatoglyphics, they try to contribute to the further definition of this multiple congenital anomaly syndrome. This entity, although several lengths of duplicated fragment or mosaicism, is characterized by high and large forehead flattened at the centre due to the abnormally large and persistent gaping anterior fontanel and sagittal (metopic sutures, consequent hypertelorism and broad nasal bridge, cutis laxa, often denounced by folded neck, joint and cardiovascular anomalies, psychomotor delay and a possible typical dermatoglyphic pattern. The phenotypic pattern seems to be similar in all the patients, although the association of anomalies appears to be correlated to the extension of the duplicated fragments.

Abnormalities, Multiple↗
PubMed1994

The predictive value of cytogenetic diagnosis after CVS based on 4860 cases with both direct and culture methods.

Cytogenetic analysis was performed in 4860 chorionic villus samples by means of both direct preparation and long-term culture. The results of the analysis were compared with a classification including all theoretical types of combinations between the chromosomal constitution of the cytotrophoblast, extraembryonal mesoderm, and fetus, with the aim of evaluating the cytogenetic variability along the trophoblast-embryo axis. Eighteen of 29 possible combinations were found demonstrating a considerable heterogeneity. A mosaic conceptus was found in 1.5 per cent of cases, with generalized mosaicisms and confined mosaicisms in 0.2 and 1.3 per cent, respectively. Cytogenetic variability along the trophoblast-embryo axis was found in 1.42 per cent of cases. Results possibly leading to diagnostic errors (false-positive and false-negative results) were found in only 1.38 per cent. False-positive results of direct preparation were the most commonly observed discrepancy (0.8 per cent), while the incidence of false-positive results of the culture method and of both methods was 0.31 and 0.16 per cent respectively. The incidence of false-negative results was 0.1 per cent, with false-negative results of direct preparation 0.08 per cent and false-negative results of both methods 0.02 per cent. False-negative results of the culture method were not found. Our data confirm the high diagnostic accuracy of chorionic villus sampling and the utility of the combined use of the two methods in minimizing diagnostic errors and in reducing the need for follow-up amniocentesis.

Chorionic Villi Sampling↗
PubMed1993

'Late' chorionic villus sampling: cytogenetic aspects.

Cytogenetic data about 145 chorionic villus samples obtained between the 13th and 35th week of gestation are reported. 'Late' chorionic villus sampling (CVS) was used to resolve different situations: failed amniotic fluid cell cultures (5 cases); confirmation of an abnormal karyotype, previously diagnosed as mosaic (14 cases); and ultrasound fetal malformation (23 cases). Most of the samples (103 cases) were analysed for the classical indications and in these cases, the principal aim was to obtain a rapid fetal karyotype. Excluding the cases used to check fetal karyotype, a chromosomal aberration was found in 11 out of 131 biopsies. In four cases of the group in which the fetal karyotype was checked (14 cases), the pathology observed at the first diagnosis was confirmed, while in the remaining ten cases the anomaly was not observed.

Chorionic Villi Sampling↗
PubMed1993

Transverse limb reduction defects after chorion villus sampling: a retrospective cohort study. GIDEF--Gruppo Italiano Diagnosi Embrio-Fetali.

A retrospective cohort study was performed in five Italian obstetrical centres from 1984 to 1991 in order to verify the association between chorionic villus sampling (CVS) and transverse limb reduction defects (TLRDs). TLRD rates by period of gestation at CVS were calculated, and the study's results were compared with data from the general population. Of the 3430 pregnancies for which CVS was performed, 2759 had a known outcome. The overall rate for TLRDs was 1 in 1143 CVS pregnancies, four times higher than that of the general population in Italy (1 in 4458). The rate of TLRDs was 2.9/1000 for CVS performed at 9 weeks' gestation and 1.0/1000 for CVS at 10 weeks' gestation. A scalp defect was detected in a pregnancy in which CVS was performed at 10 weeks. A high proportion of pregnancies lost to follow-up and the poor quality of the data may have affected the results. Nevertheless, our results suggest an association between CVS carried out at less than 10 weeks' gestation and TLRDs which is consistent with the findings of other studies. CVS should not be prepared at less than 10 weeks' gestation until additional evidence is obtained.

Chorionic Villi Sampling↗
PubMed1993

Prenatal diagnosis of an extranumerary i(22p) with normal phenotype.

A DA-Dapi and AgNOR-negative extranumerary chromosome was identified prenatally in a male fetus and also found in his normal father. Fluorescence in situ hybridization using repetitive DNA probes showed that the minute marker was positive at both ends for beta-satellite sequences, while its centromere was recognized by a 22 alphoid probe. It is concluded that the non-mosaic familial marker represents a 22p isochromosome.

Adult↗
PubMed1993

Morphology and nuclear contents in IVF embryos.

Human pre-embryos, at 2-8 cells, with different morphology have been examined for chromosome constitution. Concerning the informative pre-embryos (23/65), 11 showed a normal karyotype and in 12 an abnormal karyotype was observed; there was not a complete correspondence between pronucleation and chromosome set. Also in the interphasic pre-embryos the presence of chromatin masses at different sizes was revealed. The observation of polyploid and/or polynucleated blastomeres can suggest a failure of synchronization between cytoplasmatic and nuclear division. Mosaicism, polyploidy and polynucleation are phenomena that could be caused by in vitro culture conditions or dependent upon the genetic anomaly of the zygote.

Blastocyst↗