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Biomedical subjects

A Rasore-Quartino

Publications and source records attributed to A Rasore-Quartino.

At least 19 recordsLinked to original sources

Identification of mutations in the MSX2 homeobox gene in families affected with foramina parietalia permagna.

Foramina parietalia permagna (FPP) is an autosomal dominant condition characterized by cranial defects of the parietal bones. It can be present as an isolated feature, but it is also one of the characteristics of a contiguous gene syndrome associated with deletions on chromosome 11p11-p12. One of the proteins known to be involved in skull development is the MSX2 homeobox protein. Previously, MSX2 has been shown to be mutated in patients suffering from Boston type craniosynostosis. We have now analyzed the MSX2 gene in five families affected with FPP. An intragenic microsatellite marker did not reveal any recombination and a cumulated LOD score of +3.2 at theta = 0 was obtained. Sequence analysis further showed that in four out of five families an MSX2 mutation was responsible for the skull defect. Moreover, it appears that FPP is caused by haplo-insufficiency of the MSX2 gene. This implies that Boston type craniosynostosis and FPP are allelic variants of the same gene, with FPP caused by loss of MSX2 function and craniosynostosis Boston type due to gain of MSX2 function.

Base Sequence↗

The ALX4 homeobox gene is mutated in patients with ossification defects of the skull (foramina parietalia permagna, OMIM 168500).

Foramina parietalia permagna (FPP) (OMIM 168500) is caused by ossification defects in the parietal bones. Recently, it was shown that loss of function mutations in the MSX2 homeobox gene on chromosome 5 are responsible for the presence of these lesions in some FPP patients. However, the absence of MSX2 mutations in some of the FPP patients analysed and the presence of FPP associated with chromosome 11p deletions in DEFECT 11 (OMIM 601224) patients or associated with Saethre-Chotzen syndrome suggests genetic heterogeneity for this disorder. Starting from a BAC/P1/cosmid contig of the DEFECT 11 region on chromosome 11, we have now isolated the ALX4 gene, a previously unidentified member of the ALX homeobox gene family in humans. Mutation analysis of the ALX4 gene in three unrelated FPP families without the MSX2 mutation identified mutations in two families, indicating that mutations in ALX4 could be responsible for these skull defects and suggesting further genetic heterogeneity of FPP.

Amino Acid Sequence↗

Identification and characterization of a new human gene encoding a small protein with high homology to the proline-rich region of the SH3BGR gene.

As part of an effort to identify genes potentially involved in the Down Syndrome pathogenesis, in this paper we report the identification and characterization of a new human gene (named SH3BGRL), which shows a high homology to the SH3BGR gene, previously mapped to the Down Syndrome region of chromosome 21. The SH3BGRL gene encodes for a small protein of 114 amino acids, sharing 60% identity and 84% conservation on the amino acid level with the middle, proline-rich region of the SH3BGR gene and containing a similar SH3 (Scr homology 3) binding motif. The SH3BGRL and the proline-rich region of SH3BGR proteins appear to be highly conserved, sharing 95 and 98% identity, respectively, with the mouse homologues. A 1.9 kb transcript of the SH3BGRL gene has been found in all the tissues examined, in contrast with the expression pattern of the SH3BGR gene which is transcribed only in heart and skeletal muscle. The SH3BGR gene and its homologue, SH3BGRL, could be members of a new family of genes containing a highly conserved proline-rich functional domain. The SH3BGRL gene has been mapped by fluorescent in situ hybridization to Chromosome Xq13.3.

Amino Acid Sequence↗

Identification and characterization of a new human cDNA from chromosome 21q22.3 encoding a basic nuclear protein.

Congenital heart disease (CHD) affects over 40% of Down syndrome (DS) patients. The region proposed to contain the gene(s) for DS CHD has been restricted to 21q22.2-22.3, from D21S55 to MX1. The identification and functional characterization of the genes mapping to this region is a necessary step to understand the pathogenesis of CHD in DS. In an effort to contribute to the construction of a transcriptional map of the DS CHD region we have performed direct cDNA selection using a YAC contig that maps between ETS2 and D21S15 and cDNAs synthesised from fetal heart structures. Here we describe the identification and characterization of a new gene, WRB, that maps to 21q22.3 between ACTL5 and HMG 14 and appears to be widely expressed in adult and fetal tissues. The new gene encodes a basic protein of unknown function containing a tryptophan-rich carboxyl-terminal region and a potential nuclear localization signal. Immunofluorescence analysis shows a predominant localization in the cell nucleus. The understanding of the biological function of the protein product should clarify the potential role of WRB in the pathogenesis of DS CHD.

Adult↗

Cloning a new human gene from chromosome 21q22.3 encoding a glutamic acid-rich protein expressed in heart and skeletal muscle.

The identification and functional characterization of genes on chromosome 21 is a necessary step to understand the pathogenesis of the various phenotypic anomalies that affect Down syndrome patients. Using direct cDNA selection we have identified a new gene, SH3BGR, that maps to 21q22.3, proximal to HMG14, and is differentially expressed in heart and skeletal muscle. SH3BGR encodes a novel protein that is characterized by the presence of a proline-rich region containing the consensus sequence for a SH3-binding domain and by an acidic carboxyl-terminal region containing a glutamic acid-rich domain predicted to assume a coiled coil. The presence of two functional domains involved in protein-protein interactions suggests that SH3BGR could be part of a multimeric complex. Its overexpression might alter specific functions of muscular tissue and therefore take part in the pathophysiology of muscular hypotonia in Down syndrome.

Adult↗

Down syndrome and coeliac disease: usefulness of antigliadin and antiendomysium antibodies.

The usefulness of antigliadin (AGA) and antiendomysium antibodies (EMA) as a screening test for coeliac disease (CD) in 113 Down syndrome (DS) patients (61 children) was evaluated. AGA IgA were present in 22.1%, AGA IgG in 48.6%, EMA in 6.2%. Four symptomatic patients, AGA- and EMA-positive, were affected by CD (3.5%). In three AGA-positive and EMA-positive subjects, permission for intestinal biopsy was refused, while in two AGA-positive and EMA-negative children, the intestinal mucosa was normal. Our study confirms the association of CD and DS, and suggests the usefulness of EMA determination as a test for selecting DS patients for intestinal biopsy.

Adolescent↗

Expression of the human ETS-2 oncogene in normal fetal tissues and in the brain of a fetus with trisomy 21.

The expression of the ETS-2 proto-oncogene, located on chromosome 21, in normal fetal tissues and in neural tissue of a fetus affected by Down syndrome has been investigated. The results show that the ETS-2 proto-oncogene is expressed in almost all the tissues examined and that it is transcribed at constant levels in neural tissue between the 13th and 24th weeks. ETS-2 expression appeared to be slightly increased in Down syndrome brain compared with that of normal controls of the same gestational age.

Brain↗

Coexistence of haemophilia A and von Willebrand's disease in the same kindred.

A clinical and laboratory investigation of a kindred in which haemophilia A and autosomal recessive von Willebrand's disease (VWD) were concomitantly present is described. 3 male patients were shown to be hemizygotes for moderate haemophilia A, one female appeared to be haemophilia A carrier and 3 males showed laboratory findings consistent with heterozygosity for autosomal recessive VWD. In one woman, the pedigree and laboratory findings suggest the possibility of double heterozygosity.

Blood Coagulation Factors↗

Type A2 brachydactily: report of a new family.

A new family with the A2 type brachydactily is described. It is the first one observed in Italy and the sixth of the world literature. Brachymesophalangy of index fingers and/or second toes is the typical osseous malformation which was present in 14 individuals from 4 generations. The defect is transmitted by an autosomal dominant gene with high penetrance and variable expressivity.

Congenital Abnormalities↗