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P Burlet

Publications and source records attributed to P Burlet.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Physical study of big fragments and search strategy of genes. Application to locus of infant spinal muscular atrophies].

Spinal muscular atrophies (SMA) represent the second most common fatal autosomal recessive disorder after cystic fibrosis. Childhood SMAs are divided into severe (type I) and mild forms (types II and III). By a combination of genetic and physical mapping, a YAC contig of the 5q13 region spanning the disease locus was constructed that showed the presence of low copy-repeats in this region. Allele segregation was analyzed at the closest genetic loci detected by markers C212 and C272 in 201 SMA families. Inherited and de novo deletions were observed in 10 SMA patients. Moreover, deletions were strongly suggested in at least 18% of SMA type I patients by the observation of marked heterozygosity deficiency for the loci studied. These results indicate that deletion events are statistically associated with the severe form of SMA.

Chromosome Mapping↗
PubMed1994

Use of genetic and physical mapping to locate the spinal muscular atrophy locus between two new highly polymorphic DNA markers.

The gene for autosomal recessive forms of spinal muscular atrophy (SMA) has recently been mapped to chromosome 5q13, within a 4-cM region between the blocks D5S465/D5S125 and MAP-1B/D5S112. We identified two new highly polymorphic microsatellite DNA markers--namely, AFM265wf5 (D5S629) and AFM281yh9 (D5S637)--which are the closest markers to the SMA locus. Multilocus analysis by the location-score method was used to establish the best estimate of the SMA gene location. Our data suggest that the most likely location for SMA is between locus D5S629 and the block D5S637/D5S351/MAP-1B/D5S112/D5S357. Genetic analysis of inbred SMA families, based on homozygosity by descent and physical mapping using mega-YACs, gave additional information for the loci order as follows: cen-D5S6-D5S125/D5S465-D5S435-D5S629-SMA-+ ++D5S637-D5S351-MAP-1B/D5S112-D5S357- D5S39-tel. These data give the direction for bidirectional walking in order to clone this interval and isolate the SMA gene.

Child↗
PubMed1993

Refined linkage map of chromosome 5 in the region of the spinal muscular atrophy gene.

The genetic map in the region of human chromosome 5 that harbors the gene for autosomal recessive forms of spinal muscular atrophy (SMA) has been refined by a multilocus linkage study in 50 SMA-segregating families. Among six markers spanning 8 cM for combined sexes, four were shown to be tightly linked to the SMA locus. Multipoint linkage analysis was used to establish the best estimate of the SMA gene location. Our data suggest that the most likely location for the SMA locus is between blocks AFM114ye7 (D5S465)/EF5.15 (D5S125) and MAP-1B/JK53 (D5S112) at a sex-combined genetic distance of 2.4 and 1.7 cM, respectively. Thus the SMA gene lies in the 4-cM region between these two blocks. This information is of primary importance for designing strategies for isolating the SMA gene.

Base Sequence↗
PubMed1993

Machado-Joseph disease is genetically different from Holguin dominant ataxia (SCA2).

Machado-Joseph disease (MJD) and Holguin ataxia (SCA2) are autosomal dominant multisystem degenerations with spinocerebellar involvement that are predominant among people of Portuguese-Azorean and of Cuban descent, respectively. Their clinical distinction may at times be difficult to make in individual patients, due to significant phenotypic overlapping (similar overall age-of-onset and duration of cerebellar ataxia, eye movement, and, often, other common problems. The recent mapping of SCA2 to chromosome 12q provided another candidate region for linkage studies of MJD. Original data on 10 families with Holguin ataxia show that the locus for phenylalanine hydroxylase (PAH) on chromosome 12q is linked to SCA2 at 4 cM and is thus far its closest marker. The exclusion of linkage 15 cM on each side of PAH in 16 families with MJD shows that these two forms of dominant ataxia are genetically distinct and at different chromosomal locations (nonallelic).

Cuba↗
PubMed1992

Prenatal prediction of Werdnig-Hoffmann disease using linked polymorphic DNA probes.

Werdnig-Hoffmann disease is a common autosomal recessive neuromuscular disorder that results in paralysis and death. No treatment to prevent this disease or to alter its unremitting course has been found. Recently, linkage analysis with cloned DNA probes has shown that the mutation causing Werdnig-Hoffmann disease is located on chromosome 5q12-q14. We performed genetic analysis for the prenatal diagnosis of Werdnig-Hoffmann disease in seven at risk families. Two fetuses were diagnosed as being affected and the remainder as unaffected, and this was confirmed after birth. This study shows that prenatal diagnosis of Werdnig-Hoffmann disease has become feasible.

Chromosomes, Human, Pair 5↗
PubMed1992

Proximal spinal muscular atrophy (SMA) types II and III in the same sibship are not caused by different alleles at the SMA locus on 5q.

Proximal spinal muscular atrophy (SMA) is a group of progressive muscular diseases recently mapped to chromosome 5q. SMA is usually classified into types I-III, and there are cases of two types of SMA in the same sibship. Becker and others later proposed that these sibships might be due to the existence of several alleles at the same locus predisposing to the different forms of the disease. In a sample of four sibships in which both SMA type II and SMA type III occur, this hypothesis was clearly rejected for the SMA locus on 5q, by using information on the segregation of linked markers (P less than .001). Thus the difference between SMA type II and SMA type III is not due to different alleles at the SMA locus on 5q. This finding is suggestive of an involvement of other factors, genetic or environmental, in the determination of disease severity in SMA.

Alleles↗
PubMed1991

In situ hybridization of two markers closely flanking the spinal muscular atrophy gene to 5q12----q13.3.

In order to refine the physical location of the p105-153Ra and M4 probes which closely flank the spinal muscular atrophy gene (SMA) on human chromosome 5q, in situ hybridization has been carried out on prometaphase chromosomes. Our results demonstrate that the disease gene is located between the 5q12----q13.1 and 5q13.3 bands. The present study will hopefully contribute to microdissection of the chromosomal region of the SMA gene.

Child↗
PubMed1991

Linkage analysis in spinal muscular atrophy, by six closely flanking markers on chromosome 5.

The proximal spinal muscular atrophies (SMA) represent the second most common autosomal recessive disorder, after cystic fibrosis. The gene responsible for chronic SMA has recently been mapped to chromosome 5q by using genetic linkage studies. Among six markers mapping to this region, five were shown to be linked with the SMA locus in 39 chronic SMA families each containing at least two affected individuals. Multilocus analysis by the method of location score was used to establish the best estimate of the SMA gene location. Our data suggest that the most likely location for SMA is between loci D5S6 and D5S39. The genetic distances between these two markers are estimated to be 6.4 cM in males and 11.9 cM in females. Since meiosis were informative with D5S39 and D5S6 in 92% and 87% of SMA families, respectively, it is hoped that the present study will contribute to the calculation of genetic risk in SMA families.

Chromosome Mapping↗
PubMed1990

Mapping of acute (type I) spinal muscular atrophy to chromosome 5q12-q14. The French Spinal Muscular Atrophy Investigators.

Linkage analysis in twenty-five families with acute (type I) spinal muscular atrophy (SMA) showed that the mutant gene responsible for the disorder is tightly linked to the D5S39 locus. The mutation(s) causing the intermediate (type II) and juvenile chronic (type III) forms of SMA were also mapped to DNA marker D5S39 on chromosome 5 (5q12-q14). Thus, the three forms, which have been differentiated clinically on the basis of age of onset and clinical course, are most probably due to different mutations at a single locus on chromosome 5. Prenatal diagnosis of SMA type I will now be possible.

Acute Disease↗
PubMed1990

Gene for chronic proximal spinal muscular atrophies maps to chromosome 5q.

Proximal spinal muscular atrophies represent the second most common fatal, autosomal recessive disorder after cystic fibrosis. The childhood form is classically subdivided into three groups: acute Werdnig-Hoffmann (type I), intermediate Werdnig-Hoffmann disease (type II) and Kugelberg-Welander disease (type III). These different clinical forms have previously been attributed to either genetic heterogeneity or variable expression of different mutations at the same locus. Research has been hindered because the underlying biochemical defect is unknown, and there are insufficient large pedigrees with the most common and severe form (type I) available for study. Therefore, we have undertaken a genetic linkage analysis of the chronic forms of the disease (types II and III) as an initial step towards the ultimate goal of characterizing the gene(s) responsible for all three types. We report here the assignment of the locus for the chronic forms to the long arm of chromosome 5 (5q12-q14), with the anonymous DNA marker D5S39, in 24 multiplex families of distinct ethnic origin. Furthermore, no evidence for genetic heterogeneity was found for types II and III in our study, suggesting that these two forms are allelic disorders.

Chromosome Mapping↗