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Biomedical subjects

B Franco

Publications and source records attributed to B Franco.

15 recordsLinked to original sources
PubMed1992

Somatic cell hybrids, sequence-tagged sites, simple repeat polymorphisms, and yeast artificial chromosomes for physical and genetic mapping of proximal 17p.

Somatic cell hybrids retaining the deleted chromosome 17 from 15 unrelated Smith-Magenis syndrome (SMS) [del(17)(p11.2p11.2)] patients were obtained by fusion of patient lymphoblasts with thymidine kinase-deficient rodent cell lines. Seventeen sequence-tagged sites (STSs) were developed from anonymous markers and cloned genes mapping to the short arm of chromosome 17. The STSs were used to determine the deletion status of these loci in these and four previously described human chromosome 17-retaining hybrids. Ten STSs were used to identify 28 yeast artificial chromosomes (YACs) from the St. Louis human genomic YAC library. Four of the 17 STSs identified simple repeat polymorphisms. The order and location of deletion breakpoints were confirmed and refined, and the regional assignment of several probes and cloned genes were determined. The cytogenetic band locations and relative order of six markers on 17p were established by fluorescence in situ hybridization mapping to metaphase chromosomes. The latter data confirmed and supplemented the somatic cell hybrid results. Most of the hybrids derived from [del(17)(p11.2p11.2)] patients demonstrated a similar pattern of deletion for the marker loci and were deleted for D17S446, D17S258, D17S29, D17S71, and D17S445. However, one of them demonstrated a unique pattern of deletion. This patient is deleted for several markers known to recognize a large DNA duplication associated with Charcot-Marie-Tooth (CMT) disease type 1A. These data suggest that the proximal junction of the CMT1A duplication is close to the distal breakpoint in [del(17)(p-11.2p11.2)] patients.

Abnormalities, Multiple↗
PubMed1992

Kallmann syndrome due to a translocation resulting in an X/Y fusion gene.

The X-linked Kallmann syndrome gene was recently cloned and homologous sequences of unknown functional significance identified on the Y chromosome. We now describe a patient with Kallmann syndrome carrying an X;Y translocation resulting from abnormal pairing and precise recombination between the X-linked Kallmann syndrome gene and its homologue on the Y. The translocation created a recombinant, non-functional Kallmann syndrome gene identical to the normal X-linked gene with the exception of the 3' end which is derived from the Y. Our findings indicate that the 3' portion of the Kallmann syndrome gene is essential for its function and cannot be substituted by the Y-derived homologous region, although a 'position' effect remains a formal possibility.

Amino Acid Sequence↗
PubMed1992

Kallmann syndrome gene on the X and Y chromosomes: implications for evolutionary divergence of human sex chromosomes.

The recently identified gene for X-linked Kallmann syndrome (hypogonadotropic hypogonadism and anosmia) has a closely related homologue on the Y chromosome. The X and Y copies of this gene are located in a large region of X/Y homology, on Xp22.3 and Yq11.2, respectively. Comparison of the structure of the X-linked Kallmann syndrome gene and its Y homologue shed light on the evolutionary history of this region of the human sex chromosomes. Our data show that the Y homologue is not functional. Comparative analysis of X/Y sequence identity at several loci on Xp22.3 and Yq11.2 suggests that the homology between these two regions is the result of a complex series of events which occurred in the recent evolution of sex chromosomes.

Base Sequence↗
PubMed1991

A gene deleted in Kallmann's syndrome shares homology with neural cell adhesion and axonal path-finding molecules.

Kallmann's syndrome (clinically characterized by hypogonadotropic hypogonadism and inability to smell) is caused by a defect in the migration of olfactory neurons, and neurons producing hypothalamic gonadotropin-releasing hormone. A gene has now been isolated from the critical region on Xp22.3 to which the syndrome locus has been assigned: this gene escapes X inactivation, has a homologue on the Y chromosome, and shows an unusual pattern of conservation across species. The predicted protein has significant similarities with proteins involved in neural cell adhesion and axonal pathfinding, as well as with protein kinases and phosphatases, which suggests that this gene could have a specific role in neuronal migration.

Base Sequence↗
PubMed1991

Molecular characterization of a patient with del(1)(q23-q25).

We report a patient (S.T.) with multiple congenital anomalies and developmental delay associated with an interstitial deletion of 1q23-1q25. Molecular analysis of the deletion was performed using DNA markers that map to 1q. Five DNA markers, MLAJ-1 (D1S61), CRI-L1054 (D1S42), HBI40 (D1S66), OS-6 (D1S75), and BH516 (D1S110), were demonstrated to be deleted. Informative polymorphisms demonstrated this to be a de novo deletion of the maternally derived chromosome. Deletion status was determined using restriction fragment length polymorphism (RFLP) analysis supplemented with densitometry in the experiments where RFLP analysis was not fully informative. Deletions were confirmed by Southern analysis using genomic DNA from a somatic cell hybrid retaining the del(1)(q23-q25) chromosome that was constructed from patient S.T. Flow karyotyping confirmed the deletion and estimated that the deletion encompassed 11,000-16,000 kb. The clinical and cytogenetic characteristics of S.T. are compared with those of ten previously described patients with monosomy 1q21-1q25.

Abnormalities, Multiple↗
PubMed1990

Isolation of a marker linked to the Charcot-Marie-Tooth disease type IA gene by differential Alu-PCR of human chromosome 17-retaining hybrids.

We report the isolation of a new marker (S6.1) from band p11.2 of human chromosome 17 by differential Alu-polymerase chain reaction (Alu-PCR) of both a monochromosomal hybrid retaining a single human chromosome 17 and a hybrid retaining a del(17)(p11.2p11.2) in addition to other human chromosomes. The method is based on the preferential PCR amplification of human DNA in rodent/human hybrids when primers specific to the human Alu repeat element are used. MspI and SstI RFLPs associated with S6.1 were identified and used in linkage analysis of both a previously reported and a newly identified French-Acadian kindred segregating autosomal dominant Charcot-Marie-Tooth disease (CMT). A cumulative peak lod score of 3.41 at a peak recombination fraction of .12 indicates that this marker is linked to the CMT 1A locus but is at a distance from the disease gene. Thus, the marker S6.1 will be useful in further delineating the candidate region for the CMT gene when its location with respect to pA10-41 and 1516, two other markers from 17p11.2 which have previously demonstrated close linkage to the CMT locus, has been determined.

Animals↗
PubMed1990

Genetic mapping of autosomal dominant Charcot-Marie-Tooth disease in a large French-Acadian kindred: identification of new linked markers on chromosome 17.

We have performed linkage analysis in a large French-Acadian kindred segregating one form of autosomal dominant Charcot-Marie-Tooth disease (CMTD) (type IA) using 17 polymorphic DNA markers spanning human chromosome 17 and demonstrate linkage to several markers in the pericentromeric region, including DNA probes pA10-41, EW301, S12-30, pTH17.19, c11-2B, and p11-2c11.5. Linkage of markers pA10-41 and EW301 to CMTD type IA has been reported elsewhere. Four new markers, 1516, 1517, 1541, and LL101, which map to chromosome 17 have been identified. The marker 1516 appears to be closely linked to the CMTD locus on chromosome 17 as demonstrated by a maximum lod score of 3.42 at theta (recombination fraction) = 0. This marker has been mapped to 17p11.2 using a somatic cell hybrid constructed from a patient with Smith-Magenis syndrome [46,XY, del(17)(p11.2p11.2)]. A lod score of 6.16 has been obtained by multipoint linkage analysis with 1516 and two markers from 17q11.2, pTH17.19, and c11-2B. The markers 1517 and 1541 have been mapped to 17p12-17q11.2 and demonstrate maximum lod scores of 2.35 and 0.63 at recombination values of .1 and .2, respectively. The marker LL101 has been mapped to 17p13.105-17p13.100 and demonstrates a maximum lod score of 1.56 at a recombination value of .1. Our study confirms the localization of CMTD type IA to the pericentromeric region of chromosome 17.

Animals↗
PubMedDate not supplied

[Stress factors in psychiatric hospitalization].

The incidence of stressful life events in the six months previous to psychiatric hospitalization is studied in a group of patients allotted to different diagnostic categories but which held in common that they were at their first episode of inpatient treatment. The presence of early life events during childhood and of chronic stress during the last year is also investigated. The different kind of responses to LE are described, classified in several categories. The incidence of LE in the patients is compared with that of a group of acute traumatologic hospital inpatients. In every case it has been used the Paykel LE rating scale, the Brown and Harris interview schedule and the GAF. Results are analyzed and their implications in preventive and treatment programs in Mental Health are discussed.

Adult↗
PubMedDate not supplied

[Psychosis and cannabis consumption: study of the psychopathologic differences and risk factors].

The consumption of Cannabis has been related with different psychiatric disorders. However the role of this drug in the etiology of disorders has not yet precisely been established. It has been discussed that the existence of an Induced Psychosis is brought about by the consumption of Cannabis. The objective of our study is to determine if there exists specific characteristics in the psychotic disorders manifested after the Cannabis consumption in comparison with a group of Psychotics non consumers. We also defined the risk factors that influence the appearance of the psychopathologic troubles.

Adolescent↗