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Biomedical subjects

R S Sparkes

Publications and source records attributed to R S Sparkes.

At least 163 records · Page 9Linked to original sources

Evidence from somatic cells for crossing-over in humans.

Chromosomal and gene marker studies of somatic cells in a family with multiple chromosome translocations show apparent instability of the translocations in transmission from generation to generation. This instability is attributed to meiotic crossing-over between the involved chromosomes. Technical advances in chromosome analysis combined with human gene map information in the study of this unusual family demonstrate for the first time that crossing-over involves exchange of chromatin between nonsister chromatids of homologous chromosomes.

Chromosome Banding↗

Linkage analyses of multiple endocrine neoplasia, type 2 (MEN-2) with 23 classical genetic polymorphisms.

Linkage analyses were performed in a single large family with multiple endocrine neoplasia, type 2 (MEN-2) between 23 classical genetic polymorphisms and MEN-2. We exclude close linkage of the locus for MEN-2 with ABO, ACP1, BF, ESD, Fy, GALT, GLO1, Jk, MNSs, P, PGM1, Rh and TF, as well as absolute linkage with GPT. These results raise to about 6% the proportion of the genome that has been excluded in this one family. Somewhat positive lod scores were obtained for GC (0.92 at theta = 0), GPT (0.73 at theta = 0.1) and HP (1.49 at theta = 0.05); although not statistically significant, these findings suggest regions of the genome that warrant additional study.

Alleles↗

Genetic linkage studies in Alzheimer's disease.

We studied 18 families with Alzheimer's disease in family members, under the assumption that the disease is due to a single gene with an autosomal dominant form of inheritance. There was no evidence of linkage of Alzheimer's disease with any of 27 phenotypic gene markers analyzed, but close linkage for the Rh and MNS blood group loci was excluded.

Alzheimer Disease↗

Cowden disease: gene marker studies and measurements of epidermal growth factor.

Cowden disease (CD) is a familial syndrome characterized by tumors of the skin, oral mucosa, breast, thyroid, and intestinal epithelium. Since the syndrome is inherited as an autosomal dominant, we examined a battery of gene markers in a family with CD to detect linkage between the CD gene and known marker genes. There was no positive evidence for linkage of a CD locus with any of the markers; other investigators can add to our data to confirm and extend these findings. Additionally, we measured epidermal growth factor (EGF) in body fluids from CD patients and controls to determine if elevated EGF levels might be responsible for the widespread epithelial proliferation in CD. EGF levels in saliva, serum, plasma, and urine were similar in CD patients and control subjects. Although alterations in growth factors or their receptors may play a role in CD, excess circulating EGF is not responsible for the manifestations of the syndrome.

Adult↗

Bone-marrow transplantation for metachromatic leucodystrophy.

An 11-month-old boy with late infantile metachromatic leucodystrophy was given a bone-marrow transplant (BMT) from an HLA-identical sister; 6 months later his cerebrospinal fluid leucocytes were exclusively of donor origin. Coupled with the patient's continued developmental progress, as assessed 33 months after the procedure, the findings suggest that BMT may be an effective treatment for some congenital metabolic disorders which affect the central nervous system.

Adolescent↗

A family with three independent autosomal translocations associated with 7q32----7qter syndrome.

Two persons within the same family were discovered to be trisomic for the segment 7qter. However, several features differed from those described in other patients with this syndrome, for example, normal birth weight and neck size, cleft palate, and beaked nose. In addition to the phenotypic variation, there were three independently segregating autosomal translocations in the pedigree: t(1;7)(q43;q32), t(1;6) (p22.3;q14.1), and t(3;10)(q26.1;p11.21). This is a finding that, to our knowledge, has not been previously reported.

Adult↗

Glutamate pyruvate transaminase null allele (GPT0) in the Navajo.

During genetic linkage studies of retinitis pigmentosa in a Navajo Amerindian family, an apparent null allele of erythrocyte GPT (GPT0) was observed in a man and 2 of his daughters. This is the fourth description of a (GPT0) allele, the first outside of Europe and the first in the Navajo.

Alanine Transaminase↗

Genetic linkage analysis of the carpal tunnel syndrome.

Two generations of a family with autosomal dominant carpal tunnel syndrome were studied for genetic linkage to 20 informative polymorphic blood markers. No linkage was demonstrated between the syndrome and the markers tested; exclusion of close linkage (lod score less than -2.0) was found for MNSs, ACP, GALT, GPT, GLO, Hp, Gc, and Pi.

Carpal Tunnel Syndrome↗