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Biomedical subjects

B Dallapiccola

Publications and source records attributed to B Dallapiccola.

At least 199 records · Page 11Linked to original sources
PubMed1995

Spontaneous regression of exostoses: two case reports.

Exostoses are a common skeletal disorder. Despite their incidence, little is yet known about their origin and biological behaviour. In particular, spontaneous regression of exostoses--an extremely rare event--is still a subject for debate. In this study, we describe two additional cases of spontaneous regression of exostosis; one was a solitary lesion while the other occurred in a patient with multiple heritable exostoses. Radiographic findings are presented along with some of the theories which aim at explaining this phenomenon.

Bone Neoplasms↗
PubMed1995

The link between cytogenetics and mendelism.

High resolution chromosome analysis, molecular cytogenetics, and study of the association between specific chromosome rearrangements and single gene disorders have provided a chromosomal basis to a number of mendelian diseases. Deletions and duplications of small regions, usually less than 3 Mb in size, result in an alteration of normal gene dosage of a number of unrelated genes physically close to each other and are responsible for contiguous gene syndromes. For example, haploinsufficiency is implicated for del 8q24.1 in Langer-Giedion syndrome, del 17p13.3 in Miller-Dieker syndrome, and del 22q11.2 in DiGeorge and Velo-cardiofacial syndromes. Another chromosomal mechanism causing mendelian phenotypes is translocation, which may eventually interrupt a disease gene. It is assumed that translocation breakpoints are running through a relevant gene, hindering the production of the gene product. An example is breakage 16p13.3 associated with Rubinstein-Taybi syndrome. Females with X/autosome translocations have an almost exclusive inactivation of the normal X. Interruption of a disease gene in the translocated X causes the expression of a mendelian phenotype in the presence of an allelic recessive mutation onto the nonrearranged X. Finally, if a human gene shows exclusive expression from a single parental homologue, ie, it is imprinted, deletion of the chromosomal segment containing the active allele results in structural monosomy and functional nullisomy. This situation is illustrated by Prader-Willi and Angelman syndromes. Over seventy human genes have been precisely assigned to chromosomal regions using a cytogenetic approach. Chromosome techniques combined with molecular methods have proved to have powerful and sensitive diagnostic capabilities.

Chromosome Deletion↗
PubMed1995

Discordant clinical outcome in myotonic dystrophy relatives showing (CTG)n > 700 repeats.

A myotonic dystrophy (DM) family is described in which discordant DM phenotypes were found in the children of two affected sisters with similar CTG expansion and clinical manifestations. In this family, congenital as well as early severe childhood and later childhood onset DM coexist. This observation strengthens the limited ability of lymphocytes CTG repeat number analysis in predicting genotype-phenotype correlations in DM patients.

Adolescent↗
PubMed1995

Identification of six novel CFTR mutations in a sample of Italian cystic fibrosis patients.

The spectrum of cystic fibrosis (CF) mutations has been determined in many populations of different ethnic and geographic origins. However, in the south of Europe, the commonest mutation, delta F508, accounts for only about 50% of CF chromosomes, while identification of most of the other mutant alleles has not been achieved. In an ongoing effort to identify these alleles, we have scanned the entire coding sequences of the CF gene using a GC clamp denaturing gradient gel electrophoresis assay in a sample of 57 chromosomes from patients of italian origin. We have identified six novel mutations (C276X, H139R, R117L, S42F, A1006E and 3121-2A---> T). Each has only been found once in this sample of CF patients.

Alleles↗
PubMed1995

Sporadic trichodental dysplasia with microcephaly and mental retardation.

Trichodental syndrome is a rare autosomal dominant ectodermal dysplasia. Hair and dental anomalies have been found in different combinations in most affected persons in three families. The features of trichodental syndrome were observed in a young female in which sparse, fine, lustreless and slow growing hairs were associated with bigeminismus of inferior lateral incisors. Ultrastructural hair analysis showed consistent variation in contour of the shaft and reduced to absent cuticular scale. Distinguishing features in this patient were microcephaly and mild mental retardation.

Child, Preschool↗
PubMed1995

Screening of neurofibromatosis type 1 gene: identification of a large deletion and of an intronic variant.

Neurofibromatosis type 1 of von Recklinghausen is a common autosomal dominant disorder, characterized by peripheral neurofibromas, café-au-lait spots and Lisch nodules of the iris. The high mutation rate at the neurofibromatosis type 1 locus results in a wide range of molecular abnormalities. We have screened seven different exons of the neurofibromatosis type 1 gene, including those codifying for the GAP-related domain, using the RNA-Single Strand Conformation Polymorphism (RNA-SSCP) method in a series of 59 neurofibromatosis type 1 patients. We have also analyzed four intragenic repeats and one RFLP to detect hemizygosity and evaluate informativeness in at-risk families. One deletion and a new intronic normal variant have been detected. Thus the majority of Neurofibromatosis type 1 chromosomes have not been characterized, confirming difficulty in providing proper genetic counselling in neurofibromatosis type 1 families, even following extensive DNA analysis.

Alleles↗
PubMed1995

Joint dislocation and cerebral anomalies are consistently associated with oral-facial-digital syndrome type IV.

We present a female patient with the oral-facial-digital syndrome type IV. Our report, the tenth in the literature, describes the typical manifestations of the syndrome, combined with malformations and deformations which have not always been described in the previously reported cases. They include cerebral and renal anomalies, anal atresia and dislocation of elbows and knees.

Abnormalities, Multiple↗
PubMed1995

An autosomal recessive syndrome of cleft palate, cardiac defect, genital anomalies, and ectrodactyly (CCGE).

We report a brother and sister affected by a constellation of malformations, including cleft palate, cardiac defect, genital anomalies, and ectrodactyly (CCGE). A similar association has been reported previously by Richieri-Costa and Orquizas in a male patient born to consanguineous parents. An autosomal recessive pattern of inheritance is proposed for this syndrome.

Abnormalities, Multiple↗
PubMed1995

Neonatal spinal muscular atrophy with diaphragmatic paralysis is unlinked to 5q11.2-q13.

Two sibs affected by the severe neonatal form of spinal muscular atrophy (SMA) with diaphragmatic paralysis are described. The two sibs were discordant for the haplotypes determined by DNA markers flanking the SMA locus. This supports non-linkage of SMA to chromosome 5 in this family and indicates that the uncommon SMA type I variant associated with early onset respiratory failure maps outside the 5q11.2-q13.3 region.

Adult↗
PubMed1994

Hypoparathyroidism as the major manifestation in two patients with 22q11 deletions.

We report on two adolescents with 22q11 deletion. Their main clinical manifestation was chronic symptomatic hypocalcemia secondary to hypoparathyroidism, together with seizures and cerebral calcifications. Neither congenital cardiac abnormality nor T cell deficiency were detected. The phenotypic manifestations of the observed patients were consistent with velo-cardio-facial syndrome (VCFS). A microdeletion of chromosome region 22q11 has been demonstrated in approximately 90% of DiGeorge syndrome (DGS) patients and in 75% of VCFS patients; the association of the deletion with a wide spectrum of clinical findings suggests the existence of a contiguous gene syndrome. The presence of certain traits of DGS/VCFS should lead to investigations of the parathyroid function and molecular analysis of the 22q11 region hybridization studies.

Adolescent↗
PubMed1994

Analysis of treatment failure in patients with minimally differentiated acute myeloid leukemia (AML-M0).

Reports of treatment of patients with minimally differentiated acute myeloid leukemia (AML-M0) are limited, heterogeneous, and controversial. We verified the prognosis of this subtype by analyzing the results of 189 consecutive patients with de novo AML. Fifteen cases fitting the criteria of AML-M0 were identified. No clinical features distinguished them from other patients with AML. The median age was 61 years (range 27 to 70), with a leukocyte count ranging from 0.6 to 185 x 10(9)/L. In all cases the leukemic cells expressed CD34 and reacted with at least one of the antibodies to early myeloid antigens, ie, CD13, CD33, or myeloperoxidase. Immunophenotypic analysis also showed positivity for CD7 in seven samples and the multidrug-resistance P-glycoprotein (P-170) in six. Cytogenetic analysis was abnormal in 12 of the 13 patients in whom an adequate number of mitoses could be evaluated. No single abnormality prevailed, the most common findings being trisomy 8 (three cases) and aberrations of chromosome 7 (two cases). Antileukemic treatment differed according to age, but for remission induction, all patients received a combination of cytosine arabinoside and an anthracycline or mitoxantrone. The prognosis of patients with AML-M0 was remarkably poor as compared with the other French-American-British subtypes. Whereas the overall rate of complete remission (CR) was 58% with a median survival of 63 weeks, only 6 of the 15 patients with AML-M0 achieved a CR, and the median survival of this group was 16 weeks (range 3 to 39). The major determinant of treatment failure was unresponsiveness to chemotherapy, as only one patient died of infection during the hypoplastic phase. The CR duration of responders was short, ranging from 3 to 22 weeks, and no second remissions were observed. We conclude that conventional combination chemotherapy yields disappointing results in AML-M0. The reason for this may be the convergence of various unfavorable prognostic factors, such as (1) the high incidence of cytogenetic abnormalities; (2) the lack of differentiation features and the expression of immaturity markers such as CD34 and CD7; and (3) the frequent expression of P-170. Nonconventional therapeutic approaches should be developed to alter the prognosis of this form of leukemia.

Adolescent↗
PubMed1994

Prenatal diagnosis of X-linked retinitis pigmentosa (RP) in five pregnancies at risk.

Five pregnancies at risk for X-linked retinitis pigmentosa (RP) have been monitored by first-trimester prenatal diagnosis using DNA markers flanking the RP2 and RP3 loci. Three affected and two unaffected fetuses, including a female carrying a wild-type genotype, were predicted on the basis of marker segregation and estimation of the recombination fraction.

DNA Probes↗
PubMed1994

First-trimester prenatal diagnosis of spinal muscular atrophy using microsatellite markers.

Twenty-five pregnancies at risk for spinal muscular atrophy I (SMA I) have been monitored by first-trimester prenatal diagnosis. Microsatellite markers were used in all cases to amplify polymorphic regions at the D5S125, D5S435, D5S39, D5S127, and D5S112 loci. All families, including 12 SMA I pedigrees with a decreased index child, were fully informative for DNA analysis. Three fetuses were predicted to be affected and 22 fetuses were predicted to be unaffected. Twenty-two newborns were unaffected by clinical examination at birth. These results support the accuracy of SMA I prenatal diagnosis based on linkage analysis.

Base Sequence↗