No description available.

No description available.

No description available.

Retinitis pigmentosa (RP) defines a group of hereditary retinal dystrophies characterised by a progressive deterioration of night vision and reduction of the visual field due to photoreceptor degeneration. RP shows both clinical and genetic heterogeneity and has X- linked, autosomal recessive and autosomal dominant forms of inheritance. In addition, a 'digenic' form of inheritance had also been reported. To date, positional cloning and candidate gene approaches have identified more than 20 genes and gene loci responsible for RP, and the number is increasing. In the present study, three Scottish RP families were included in a linkage study, to determine if the disease locus in each of these families mapped to any of the known RP loci on chromosomes 7 (7p and 7q), 8 and 19. Significant positive LOD scores were obtained for family G-adRP, with markers mapping within the RPIO locus (7q31-q32). The highest LOD score obtained was 3.913 (at 0% recombination) with marker D7S514. Results for the remaining two families were generally inconclusive. However, LOD scores obtained indicated that linkage to 7p and 7q was significantly excluded for family F-adRP. No conclusive exclusion of linkage was obtained for family C-RP. Two candidate genes exist within the RPIO candidate region, namely the blue cone pigment gene (BCP) and the metabotropic glumate receptor 8 (GRM8) gene. Mutation screening was performed using SSCP analysis to evaluate the involvement of these genes in the pathogenesis of RP in family G-adRP. An A->C polymorphism was observed in the final base of codon 122 of the BCP gene (exon 2). The amino acid residue (glycine) is not altered, however, and is thus unlikely to be involved in the disease process. Furthermore, this polymorphism was noted in both affected and unaffected individuals of family G-adRP, as well as in control individuals. For the GRM8 gene, only eight out of ten exons were available for analysis at the time of study. SSCP mobility shifts were detected in 4 PCR fragments (exons IV, V and X, and exon VIIIb). Sequencing analysis of exon VIIIb revealed an A-C polymorphism in the first base of codon 561. The involvement of this polymorphism in the disease process is unlikely as the change does not alter the encoded amino acid (arginine) and it was detected in both affected and unaffected members of G- adRP. In exon X, a heterozygous C>T sequence transition was noted 29bp downstream of the stop codon. However, the shift was again found in both affected and unaffected individuals of family G-adRP, therefore unlikely to be pathogenic. Sequence analysis of the remaining two exons (exons IV and V) did not reveal any deviation from the published control sequence. The direct cDNA selection, technique was employed in the attempt to isolate transcripts from the candidate region. YACs spanning the region of interest were obtained and their inserts verified by FISH and PCR-based STS content screening. Selection was performed on human retinal cDNA library preparations, and the selected products were subcloned to create a selected-cDNA library for further analysis. Sequencing analysis of a subset (27clones) of the selected products indicated that some fragments were indeed derived from within the 7q3 l-q32 region, as shown by BLAST and FASTA sequence homology searches, although most were repetitive in origin. Hits to known genes or other transcribed sequences (ESTs or cloned cDNA) were also obtained, although several of these genes have been shown to map elsewhere in the genome. At present, family G-adRP is the fourth autosomal dominant RP family whose disease locus was mapped within the RPIO region (7q31-q32). All known candidate genes identified to date have been excluded, which necessitates positional cloning strategies to be employed. Using the direct cDNA selection technique, a library of cDNA fragments putatively isolated from a portion of the RPIO candidate region has been constructed in this study. However, time was a limiting factor, and as a result, only a minor subset (less than 15%) of the selected-cDNA library was analysed. Further analysis and characterisation of the selected cDNAs is warranted to identify clones that represent (novel) transcripts mapping within the 7q31-q32 candidate region, which will undoubtedly expedite the identification of the RPIO gene.

No description available.

A Thesis submitted to the Faculty of Medicine, University of the Witwatersrand, Johannesburg, for the Degree of Master of Science JOHANNESBURG 1986 / The adenosine deaminase enzyme from a Xhosa tribesman has been characterized. Red blood cell activity levels were 6-9% of normal whereas his white cell ADA levels were about 30% of normal. The enzyme's stability at 57°C was shown to be greatly reduced suggesting a mutation resulting in an enzyme with reduced stability in vivo. It was concluded that the discrepancy in ADA activity levels between red and white blood cells was due to the red cells being anucleate. The proband's residual ADA was found to have a Michaelis Constant (K ) for adenosine m of 47.9 ♦ IS.BuM, a value which is not significantly different from that of normal ADA (51.7 ± 11.4ufl). Red cell deoxy-ATP levels were measured and found to be elevated two-to-three times over normal levels. Red cells from ADA-deficient patients with severe combined immunodeficiency (SCID) have been reported with deoxy-ATP levels elevated about 1 000 times. It was concluded that the slight elevation of deoxy-ATP levels in the proband were too low to have any noticeable effect on functions of his immune system. Starch gel electrophoresis of red cell ADA from members of the proband's family in conjunction with red cell ADA activity levels suggested that both parents carried a gei e for 'partial' ADA deficiency, both of which had been inherited by the proband as well as one of his sibs. Isoelectric focusing studies suggested that the two, parental AUA partial deficiency genes were different from one another. It was also found that another rare allele of ADA, possibly ADA ',was segregating within the same family although this event appaars to be unconnected with the ADA partial deficiency.

Hereditary endometrial cancer (EC) is a Lynch syndrome (LS) related cancer variant and 2-10% of all EC are hereditary. The aim of this study was to develop a method for analysis of microsatellite instability (MSI) as such analysis would assist in identifying potential LS patients with EC at an early state of their disease, before a possible second cancer is developed in another organ. Twenty-six patients with adenocarcinoma in the endometrium, diagnosed at Uppsala University Hospital in Sweden between 1993 and 2012, were included in the study. Seven of these patients were also diagnosed with LS and the rest were sporadic EC. DNA was extracted from the patients’ formalin-fixed and paraffin-embedded tissues. The extracted DNA was subjected to a multiplex PCR with fluorescently labelled primers and then analysed by using capillary electrophoresis. Of the sporadic EC, 26% was MSI-High, which correlates well with published data. Of the LS patients, 83% was MSI-High. The outcome of this project resulted in that MSI analysis is now a validated and established method used in the process of identifying potential LS among patients with EC.

Background: A positive BRCA1/2 carrier status impacts an individual on various levels with implications to an entire family due to shared family genes. A gap exists in the research literature in the area of parental disclosure and non-disclosure of genetic test results to younger offspring. Additional studies in the area of parental disclosure and non-disclosure will help clinicians to better support parents and children during this process. Purpose: The purpose of this qualitative hermeneutic phenomenological research study was to attain an understanding of the lived experience of parents’ perceptions regarding the disclosure and non-disclosure of a positive BRCA1/2 test result to minors. Results: The essence of the lived experience of the 15 study participants was a parental desire for healthcare professionals to take the BRCA1/2 conversation a step further which was uncovered in the seven research themes. Discussion: For the study participants interviewed, stories reflected an identified need for axillary support that specifically pertained to the disclosure and non-disclosure decision-making process. Findings suggest ways in which parental support may be coordinated though intra and interdisciplinary team approaches to patient care. Implications: The findings from this study support the need for mixed methods studies of parental disclosure and non-disclosure of BRCA1/2 test results to minors. Specifically, studies assessing positive BRCA1/2 males and individuals from our gay community, members from our lower socioeconomic and diverse ethnic community, and fathers and children’s perceptions regarding the disclosure of parental BRCA1/2 test results to minors are warranted.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2009. / Härtill 4 uppsatser.

archives@tulane.edu / 1 / Angela Crist