PubMed Health⌕ Search

Biomedical subjects

J L Steckley

Publications and source records attributed to J L Steckley.

5 recordsLinked to original sources

A genome-wide screen and linkage mapping for a large pedigree with episodic ataxia.

Episodic ataxias are ion channel disorders characterized by attacks of incoordination. The authors performed a genome-wide screen in a large pedigree segregating a novel episodic ataxia and found significant linkage on 1q42 with a multipoint lod score of 3.65. Haplotype analysis and fine mapping yielded a peak 2-point lod score of 4.14 and indicated a 4-cM region on 1q42 that is likely to harbor an episodic ataxia gene.

Adolescent↗

TCR beta polymorphisms and multiple sclerosis.

A total of 267 families with two or more siblings with multiple sclerosis (MS) were genotyped with 14 restriction fragment length polymorphisms at the TCR beta locus. A nonparametric linkage analysis of the data showed no evidence for linkage to this locus (mlod=0.11). No significant allelic or haplotype transmissions were observed in the total sample of 565 patients. After stratification for the presence of HLA DRB1*15, an association was observed between the BV25S1*1-BV26S1*1-BV2S1*1 haplotype and MS (P=0.00089). This was not significant upon correction for multiple comparisons. It was also not significant when the haplotype frequency in affected individuals was compared to a normal control sample (P=0.77). Furthermore, the associated haplotype was followed-up in an independent sample of 97 nuclear families with a single DRB1*15-positive child with MS. The BV25S1*1-BV26S1*1-BV2S1*1 haplotype did not show significant evidence for transmission distortion but the same trend was seen (P=0.21). There were no significant associations observed in the DRB1*15-negative patients and no detectable difference was seen in the DRB1*15-positive BV25S1*1-BV26S1*1-BV2S1*1 association when comparing different subgroups based on clinical course of MS. These results show no evidence for linkage and fail to establish an association between MS susceptibility and the TCR beta locus.

Female↗

No evidence to support CTLA-4 as a susceptibility gene in MS families: the Canadian Collaborative Study.

Two polymorphisms of the CTLA-4 gene were genotyped in 232 sibling pairs affected with multiple sclerosis (MS) from 185 families. The CTLA-4 polymorphisms genotyped were a 3' untranslated (AT)(n) microsatellite and an alanine/threonine RFLP of exon 1. There was no evidence observed for linkage by either identity-by-descent (ibd) or identity-by-state (ibs) methods. A transmission disequilibrium test (TDT) was performed and no preferential transmission of alleles was observed. Upon stratification of patients, there was no preferential transmission observed based upon gender, by presence or absence of HLA*DRB1*15, by ethnicity or by clinical course of the disease. CTLA-4 does not appear to be a major MS susceptibility locus in Canadian multiplex families.

Abatacept↗

An autosomal dominant disorder with episodic ataxia, vertigo, and tinnitus.

The authors report an autosomal dominant episodic ataxia that is clinically distinct from the other episodic ataxias. Vestibular ataxia, vertigo, tinnitus, and interictal myokymia are prominent; attacks are diminished by acetazolamide. Linkage analyses of markers flanking the EA1 and EA2 loci demonstrate genetic exclusion from the other autosomal dominant episodic ataxias. The authors suggest EA3 for periodic vestibulocerebellar ataxia and EA4 for the disorder described here.

Adolescent↗

Genetic analysis of vitamin D related genes in Canadian multiple sclerosis patients. Canadian Collaborative Study Group.

The objective of this study was to investigate genes involved in the metabolism and function of vitamin D as candidate genes for genetic susceptibility to MS. Restriction fragment length polymorphisms and highly polymorphic microsatellite markers within or very close to the 1,25(OH)2D3 receptor (VDR) [12q14], the vitamin D binding protein (DBP) [4q12], and the 25(OH)D2 1alpha-hydroxylase [12q13] loci were analyzed for linkage or association with MS. We found no evidence for linkage or association of these candidate genes with MS in the Canadian population.

Alleles↗