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G Filippi

Publications and source records attributed to G Filippi.

83 records · Page 5Linked to original sources
PubMedDate not supplied

Fragile-X mutation and Klinefelter syndrome: a reappraisal.

To date the concurrent presence of the fragile-X and the Klinefelter syndromes in the same individual has been found at least 8 times either in the course of screening for the fra(X) condition in mentally retarded males or among the relatives of fra(X) propositi. Given the high frequency of both events in the general population and the heterogeneous approaches with which the above cases were ascertained, it has not been possible to determine unequivocally so far whether the finding is purely coincidental or the expression of some underlying biological relationship. To evaluate the issue, we have screened a large population of institutionalized mentally retarded males for microorchidism, and submitted to a full karyotype analysis and fra(X) testing the patients that were found to have marked bilateral microorchidism. Thus, in a total of 32 microorchidism patients identified among 1115 mentally retarded males, we found 6 to have a 47,XXY chromosome complement in all (or in most) of their cells, with one of them having also the fra(X) marker in 9% of the metaphases examined. In addition, another bearer of the fra(X) marker (but only in 4% of his metaphases) was found among 26 47,XXY mentally normal males ascertained throughout routine cytogenetic analysis of males with microorchidism referred to our genetic counseling unit during the last 10 years. In our laboratory the fra(X) marker has never been observed with such a frequency in a total of several hundred normal XY males and XX females studied as control cases in the course of previously reported family and population studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Physical and genetic mapping of the CDR gene with particular reference to its position with respect to the FRAXA site.

This study narrows down the localization of the gene coding for the cerebellar degeneration-related protein (CDR 34) to the upper boundary of the FRAXA and reports the finding of two common RFLPs respectively identified at an RsaI site flanking the 3' end of the gene and at a Hincll site flanking its 5' end. Segregation analysis carried out in the CEPH-pedigrees for the new CDR/RsaI-RFLP versus other polymorphic loci of the region has established a tight linkage with the markers DXS105/DX98 and absence of measurable linkage with two clusters of markers respectively located proximally to the FRAXA (F9, DXS102, DXS51, and DXS369) or distally to it (DXS52, DXS304). In addition, two recombinants were found among 23 scorable sibs identified in the Sardinian pedigrees segregating for the Martin-Bell Syndrome (MBS) and the CDR/RsaI variants. The overall evaluation of the in situ and genetic data reported suggest that the CDR locus 1) is located at the upper boundary of the FRAXA site; 2) is distal to DXS51 and proximal to DXS 389; and 3) segregates in a close linkage association with the loci DXS98 and DXS105 and, to a lesser extent, with the locus for MBS.

Antigens, CD34↗
PubMedDate not supplied

Premutation for the Martin-Bell syndrome analyzed in a large Sardinian family: II. Neuropsychological and behavioral data.

We describe the neuropsychological and behavioral profiles of 48 critical members of a previously reported Sardinian pedigree [Filippi et al., 1991], in which the fully manifested Martin-Bell syndrome (MBS), observed among males of the latest generations, is clearly the result of step-wise mutational events occurred repeatedly along the X-chromosome pathway linking all of them to a common ancestress, who must have been heterozygous for a fragile X (FRAX) premutation. We found that the unquestionable presence in the family of normal transmitting males and females could not be determined on the basis of neuropsychological and behavioral data alone. However, we think that the large variation observed in the expression of most diagnostic parameters among the MBS patients and their close female relatives in this family, could by itself be a connotation of the genome instability which characterizes the FRAX region in pedigrees segregating for the FRAX premutation(s) and mutation(s).

Behavior↗
PubMedDate not supplied

Neuropsychological studies in families with fragile-X negative X-linked mental retardation.

Neuropsychological studies were performed in 82 subjects of 12 families with x-linked, fragile X negative, mental retardation (MR). Subjects were examined with Wechsler tests (WPPSI, WISC-R or WAIS, according to their capabilities), Progressive Matrices, Bender or Santucci and memory tests. Physical findings in 5 families were characterised by micro-orchidism (MiO), microcephaly (MiC), short stature (SS) and non-specific facial features (XMR +/- MiO +/- MiC +/- SS). The 11 males with MR had a very low IQ, ranging from 13 to 37 (mean 21.2 +/- 8.8); this did not constitute a profile definition. Among the females of their families, 4 had subnormal or borderline IQ, respectively 74, 66, 38 and 37. A second group (2 families) had MiO but with normal stature and occipito-frontal circumference (XMR +/- MiO). The 7 males with MR had an IQ ranging from 24 to 43 (mean 35.1 +/- 5.8) and showed frequently better results in performance than in verbal subtests. In these 2 families, 5 females had subnormal or borderline IQ, respectively 77, 72, 71, 70 and 20. In the 5 families of the third group, XMR +/- MaO (fraX-), several affected males had macro-orchidism (MaO) and facial changes similar to those of fragile X syndrome. IQ variability, also in the same family (e.g.: the 3 brothers of family 3 had, respectively, an IQ of 26, 28 and 68; and 2 brothers of family 1 had an IQ of 13 and 63) and different profiles. Two females were severely affected (IQ 16 and 24), while another 4 had an IQ, respectively, of 63, 69, 71 and 72.

Adult↗
PubMedDate not supplied

Prenatal diagnosis of the fragile-X in male monozygotic twins: discordant expression of the fragile site in amniocytes.

A prenatal diagnosis of the fragile-X syndrome in monozygotic male twins is reported. The expression of the fragile site was discordant in amniotic cells. Fetal blood and, after therapeutic abortion, skin fibroblasts were positive in both fetuses. Our data suggest that great care should be taken when using amniocytes for prenatal diagnosis of the fragile-X syndrome.

Adult↗
PubMedDate not supplied

Experimental determination of the operative parameters for a double antibody solid phase radioimmunoassay of luteinizing and follicle-stimulating hormones in serum.

The experimental parameters of a Double Antibody Solid Phase (DASP) radioimmunoassay (RIA) for the determination of serum luteinizing (LH) and follicle-stimulating (FSH) hormones, are described. The lowest detection limits can be fixed at about 20 pg LH and about 10 pg FSH. Evidence of parrallelism among the dose-response curves and the dilution curves of different sera is provided for FSH-RIA and for about 92% of the tested sera for LH-RIA. The antisera dilution curves are reported (final titres: (/160 - 10(3) for anti-LH and 1/40 - 10(3) for anti-FSH). The traditional cross-reaction study in buffer indicates that 5.38 and 46.8) muU TSH/ml mimic 1 ng LH/ml and 1 ng FSH/ml respectively. The regression-line equations of antigen recovery (f = found, e = expected) are: lH f = 0.94 LH e + 0.91 and FSH f = 1.05 FSH e + 0.17; the same equations when TSH is added become: LH f = 1.30 LH e + 1.46 and FSH f = 1.40 FSH e -- 0.37. It is concluded that LH-RIA is interfered by TSH over 8-10 muM TSH/ml and in function of TSH concentration; FSH-RIA is not interfered by TSH up to 4-5 ng FSH/ml; for higher FSH levels, TSH interferes according to a linear law (angular coefficient 1.40) and not in function of its concentration. LH and FSH levels throughout normal menstrual cycle in follicular phase, centre peak and luteal phase are: 3.14 +/- 1.16, 16.71 +/- 12.99, 2.31 +/- 1.04 ng LH/ml (mean +/- 2SD) and 3.57 +/- 0.95, 5.72 +/- 2.90, 2.57 +/- 0.80 ng FSH/ml (mean +/- 2SD) respectively. Finally, the within-assay coefficient of variation is 7.65% for LH-RIA and 3.16% for FSH-RIA.

Adult↗