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Biomedical subjects

H K Cousin

Publications and source records attributed to H K Cousin.

12 recordsLinked to original sources
PubMed1992

Exclusion of linkage between hypokalemic periodic paralysis (HOKPP) and three candidate loci.

Hypokalemic periodic paralysis (HOKPP) is an autosomal dominant neuromuscular disorder characterized by flaccid paralysis accompanied by lowered serum potassium levels. We have tested polymorphic markers linked to the adult skeletal muscle sodium channel (SCN4A) locus at 17q23-q25, the T-cell receptor beta (TCRB) locus at 7q35, and the H-Ras cellular proton-cogene locus (HRAS) at 11p15.5 for linkage with the affected phenotype in a single multigenerational pedigree. No evidence for genetic linkage to HOKPP was found at any of the candidate loci.

Chromosome Mapping↗
PubMed1992

Linkage analysis of candidate loci in autosomal dominant myotonia congenita.

Electrophysiologic studies in patients with autosomal dominant myotonia congenita (ADMC) have implicated defects of both muscle membrane sodium and chloride channels. An adult skeletal muscle sodium channel (ASkM1) gene maps to chromosome 17q23-25, and defects in this gene are almost certainly responsible for at least three variants of hyperkalemic periodic paralysis (HPP)--myotonic HPP, nonmyotonic HPP, and paramyotonia congenita. A gene for a muscle chloride channel has not yet been mapped in humans, but has been identified in the mouse. The gene for the cystic fibrosis transmembrane regulator (CFTR), which has chloride channel properties, is located on chromosome 7q31. This region is syntenic with the area of mouse chromosome 6 that contains the muscle chloride channel gene, a defect in which is responsible for the ADR phenotype, a murine model of myotonia. We performed linkage analysis using chromosome 17q polymorphisms at D17S74, SCN4A, and GH1, two chromosome 7q31 restriction fragment length polymorphisms, and a dinucleotide repeat polymorphism within the CFTR gene (CFTR-DNR), in three pedigrees with ADMC. The lod scores obtained show that the locus for ADMC is not at ASkM1 and is excluded from a region of at least 24 cM on either side of the CFTR gene.

Chromosome Mapping↗
PubMed1992

Linkage of Thomsen disease to the T-cell-receptor beta (TCRB) locus on chromosome 7q35.

The chromosomal localization of the gene for Thomsen disease, an autosomal dominant form of myotonia congenita, is unknown. Electrophysiologic data in Thomsen disease point to defects in muscle-membrane ion-channel function. A mouse model of myotonia congenita appears to result from transposon inactivation of a muscle chloride-channel gene which maps to a region of mouse chromosome 6. The linkage group containing this gene includes several loci which have human homologues on human chromosome 7q31-35 (synteny), and this is a candidate region for the Thomsen disease locus. Linkage analysis of Thomsen disease to the T-cell-receptor beta (TCRB) locus at 7q35 was carried out in four pedigrees (25 affected and 23 unaffected individuals) by using a PCR-based dinucleotide repeat polymorphism in the TCRB gene. Two-point linkage analysis between Thomsen disease and TCRB showed a maximum cumulative lod score of 3.963 at a recombination fraction of .10 (1-lod support interval .048-.275). We conclude that the Thomsen disease locus is linked to the TCRB locus in these families.

Base Sequence↗
PubMed1978

Linoleic acid in multiple sclerosis: failure to show any therapeutic benefit.

We have studied the effect of a dietary supplement with linoleic acid (LA) in 76 patients with MS. We could detect no effect of this supplement on the progression of neurological findings, the relapse rate, or the severity of relapses. We were also able to show that oral supplementation with a linoleic acid preparation would raise the blood level of LA in these patients. We were unable to show that there was any reduction in the linoleic acid blood levels associated with acute relapses of MS during this study.

Diet↗
PubMed1977

HLA in multiple sclerosis. Relationship to measles antibody, mitogen responsiveness and clinical course.

In our study of multiple sclerosis (MS) patients we have found significant increases in the A3, B7, and DW2 antigens. We have also studied immune responses in these same patients. There was elevation of measles antibodies in MS patients positive for A3, B7, and B18 as compared to MS patients without those antigens. The first study of mitogen responsiveness (31 patients) showed a decreased response in A3, and B7 positive patients. Study of a second and a larger group (62 patients), at a different time, failed to confirm this deficiency. We propose that there is a genetically linked (HLA) T cell deficiency in some MS patients and that this deficiency results in high humoral responses to measles antigens and an evanescent (or cyclical) reduced T cell response to mitogen.

Antibodies, Viral↗
PubMed1977

HLA-D typing with an association of Dw2 and absent immune responses towards herpes simplex (type i) antigen in multiple sclerosis.

We have confirmed that HLA-Dw2 is increased in MS patients to 47% (normals 20%). Lymphocyte transformation and antibody studies with herpes simplex antigen show that many of the DW2-positive MS patients have low or absent responses. The association of low responses to HSV and the presence of Dw2 is statistically significant at a p value less than 0.01.

Antibody Formation↗
PubMed1977

HLA antigens and mitogen responsiveness in multiple sclerosis.

Thirty-one MS patients were studied for their in vitro response to lymphocyte mitogens. Patients with HLA antigens A3 and/or B7 had lower mean peak responses to all three mitogens compared to A3, B7-negative patients. The difference in the mean peak responses to Con A were significantly different at a level of p less than 0.05. This supports the concept of a histocompatibility-linked T-cell deficiency in many patients with MS.

HLA Antigens↗