Biomedical subjects

Denise Syndercombe-Court

Publications and source records attributed to Denise Syndercombe-Court.

8 recordsLinked to original sources

PubMed2006

Trinucleotide repeat dynamic mutation identifying susceptibility in familial and sporadic chronic lymphocytic leukaemia.

Chronic lymphocytic leukaemia (CLL) has a strong hereditary component, but an understanding of predisposition genes is poor. Anticipation with familial CLL has been reported, although the molecular mechanism is unknown. Expansion of trinucleotide repeat sequences underlies anticipation observed in neurodegenerative disease. A polymerase chain reaction-based assay was used to analyse the stability of ten CCG- and CAG-trinucleotide repeat tracts in 18 CLL families and 140 patients with the sporadic form of the disease. The study suggests that anticipation, if it occurs in CLL, is not linked to CCG- and CAG-repeat expansion, however, variation in repeat length at certain loci (FRA16A) may permit identification of susceptible family members. In addition, polymorphisms with prognostic significance were identified. These were high length (but not expanded) repeats at FRA11B (P = 0.01), ATXN1 (P = 0.032) and ATXN3 (P = 0.022), all associated with poor risk disease.

Age of Onset↗

PubMed2006

A multiplex assay with 52 single nucleotide polymorphisms for human identification.

A total of 52 SNPs reported to be polymorphic in European, Asian and African populations were selected. Of these, 42 were from the distal regions of each autosome (except chromosome 19). Nearly all selected SNPs were located at least 100 kb distant from known genes and commonly used STRs. We established a highly sensitive and reproducible SNP-typing method with amplification of all 52 DNA fragments in one PCR reaction followed by detection of the SNPs with two single base extension reactions analysed using CE. The amplicons ranged from 59 to 115 bp in length. Complete SNP profiles were obtained from 500 pg DNA. The 52 loci were efficiently amplified from degraded samples where previously only partial STR profiles had been obtained. A total of 700 individuals from Denmark, Greenland, Somalia, Turkey, China, Germany, Taiwan, Thailand and Japan were typed, and the allele frequencies estimated. All 52 SNPs were polymorphic in the three major population groups. The mean match probability was at least 5.0 x 10(-19) in the populations studied. Typical paternity indices ranged from 336 000 in Asians to 549 000 in Europeans. Details of the 52 SNP loci and population data generated in this work are freely available at http://www.snpforid.org.

DNA Fingerprinting↗

PubMed2005

Human peripheral blood monocytes express protease receptor-2 and respond to receptor activation by production of IL-6, IL-8, and IL-1{beta}.

Protease-activated receptor-2 (PAR-2) belongs to a family of G-coupled receptors activated by proteolytic cleavage to reveal a tethered ligand. PAR-2 is activated by trypsin and trypsin-like serine proteases and experimentally, by receptor-activating peptides (APs), which mimic the tethered ligand. PAR-2 has recently been implicated in proinflammatory immune responses. For example, PAR-2(-/-) mice exhibit markedly diminished contact hypersensitivity reactions and are completely resistant to adjuvant-induced arthritis. The present study shows that human blood monocytes express low-level cell-surface PAR-2 ex vivo, which is up-regulated upon cell purification by the mobilization of intracellular stores of PAR-2 protein. PAR-2 expression is also present on monocyte-derived macrophages, but only a small proportion of monocyte-derived dendritic cells (DC) is PAR-2(+), and blood DC are PAR(-). Freshly isolated monocytes responded to the PAR-2 AP ASKH 95 (2-furoyl-LIGKV-OH) with the generation of a calcium flux and production of interleukin (IL)-1beta, IL-6, and IL-8. The results presented thus suggest that PAR-2 contributes to inflammatory responses by inducing the production of proinflammatory cytokines in peripheral blood monocytes.

Calcium↗

PubMed2005

Introduction of an single nucleodite polymorphism-based "Major Y-chromosome haplogroup typing kit" suitable for predicting the geographical origin of male lineages.

The European Consortium "High-throughput analysis of single nucleotide polymorphisms for the forensic identification of persons--SNPforID", has performed a selection of candidate Y-chromosome single nucleotide polymorphisms (SNPs) for making inferences on the geographic origin of an unknown sample. From more than 200 SNPs compiled in the phylogenetic tree published by the Y-Chromosome Consortium, and looking at the population studies previously published, a package of 29 SNPs has been selected for the identification of major population haplogroups. A "Major Y-chromosome haplogroup typing kit" has been developed, which allows the multiplex amplification of all 29 SNPs in a single reaction. Allele genotyping was performed with a single base extension reaction (minisequencing) detected by CE. The validation of the multiplex was performed in a total of 1126 unrelated males distributed among 12 worldwide populations. The approach takes advantage of the specific geographic distribution of the Y-chromosome haplogroups and demonstrates the utility of binary polymorphisms to infer the origin of a male lineage.

Africa↗

PubMed2004

The EDNAP mitochondrial DNA population database (EMPOP) collaborative exercises: organisation, results and perspectives.

This paper presents an overview of the organisation and the results of the collaborative exercises (CE) of the European DNA Profiling (EDNAP) Group's mitochondrial DNA population database project (EMPOP). The aim of the collaborative exercises was to determine whether uniformity of mtDNA sequencing results could be achieved among different laboratories. These were asked to sequence either the complete mtDNA control region or the two hypervariable regions HVI (16024-16365) and HVII (73-340) from DNA extracts, buccal swabs or bloodstains, proceeding in accordance with the protocol and strategies used in each individual laboratory. The results of the collaborative exercises were employed to identify possible sources of errors that could arise during the analysis and interpretation of mtDNA profiles. These findings were taken as a basis to tentatively make suitable arrangements for the construction of a high quality mtDNA database. One hundred fifty mtDNA profiles were submitted to the evaluating laboratory, and disaccording profiles were classified into four groups corresponding to the source of error: clerical errors, sample mix-ups, contaminations and discrepancies with respect to the mtDNA nomenclature. Overall, 14 disaccording haplotypes (16 individual errors) were observed. The errors included 10 clerical errors, 3 interpretation problems, 2 cases of sample mix-up and 1 case of point heteroplasmic mixture, where the 2 sequencing reactions brought inconsistent base calls. This corresponds to an error rate of 10.7% in a virtual mtDNA database consisting of the collaborative exercise results. However, this estimate is still conservative compared to conclusions drawn by authors of meanwhile numerous publications critically reviewing published mtDNA population databases. Our results and earlier published concerns strongly emphasize the need for appropriate safety regulations when mtDNA profiles are compiled for database purposes in order to accomplish the high standard required for mtDNA databases that are used in the forensic context.

Clinical Laboratory Techniques↗

PubMed2002

An Israeli Arab patient with a de novo TNFRSF1A mutation causing tumor necrosis factor receptor-associated periodic syndrome.

OBJECTIVE: To investigate genetic susceptibility to recurrent fevers, generalized severe myalgia, and migratory erythema in an Israeli Arab child with no family history of similar disease. METHODS: DNA sequencing of exons 1-6 of the TNFRSF1A gene (formerly TNFR1) was performed in the patient and his parents to determine the presence of the autosomal-dominant tumor necrosis factor receptor-associated periodic syndrome (TRAPS); informative markers spanning the TNFRSF1A locus were used to genotype all available members of the patient's family. The TNFRSF1A gene was subsequently screened in 69 healthy Arab controls and 96 Caucasian controls. Formal forensic paternity testing was performed on the child. RESULTS: We found a de novo missense mutation in exon 3 of the TNFRSF1A gene, involving a novel C-->T transition encoding a Cys70Arg (C70R) variant, in the Israeli Arab patient. Eight of the common familial Mediterranean fever (FMF) gene MEFV mutations were excluded. This mutation was not present in the parents or siblings, or among the 69 healthy Arab controls. However, another TNFRSF1A variant, Pro46Lys (P46L), was present in 1 of the Arab controls. CONCLUSION: We have identified a TNFRSF1A mutation associated with periodic fever in an Arab patient, and a TNFRSF1A variant, which is variably pathogenic in Caucasians, in an Arab control. This is the first report of a de novo mutation in periodic fevers in general, and also of TRAPS in the Arab population. These findings demonstrate the need to include TRAPS in the differential diagnosis of recurrent fevers in this population.

Adolescent↗

PubMed2002

Non-myeloablative bone marrow transplantation in an adult with Wiskott-Aldrich syndrome.

Early bone marrow transplant is now standard treatment for infants with severe immunodeficiencies such as Wiskott-Aldrich Syndrome (WAS), but results in older children and adults are poor. Non-myeloablative transplant has shown promise in the treatment of older children, who are likely to have active infections and organ damage. We describe a non-myeloablative transplant of a 26-year-old man with WAS, undertaken because of severe infections and vasculitis. Partial engraftment and immunorestoration were achieved. The patient is well 1 year post transplantation.

Adult↗

PubMed2002

Haplotype combinations of calpain 10 gene polymorphisms associate with increased risk of impaired glucose tolerance and type 2 diabetes in South Indians.

Haplotype combination 112/121 and its intrinsic variants (UCSNP43, -19, and -63) identified within the calpain 10 gene are associated with increased risk of type 2 diabetes in Mexican-Americans. We evaluated whether this haplotype combination and its constituent haplotypes and variants contribute to increased susceptibility to impaired fasting glucose (IFG)/impaired glucose tolerance (IGT) and type 2 diabetes in a South Indian population. Two study groups were used: 95 families ascertained through a proband with type 2 diabetes and 468 subjects recruited as part of an urban survey (69.1% with normal glucose tolerance, 12.8% with IFG/IGT, and 18.2% with type 2 diabetes). The four-locus haplotype combination 1112/1121 (UCSNP44, -43, -19, and -63) in South Indians conferred both a 10.7-fold increased risk for IFG/IGT (P = 0.001) and a 5.78- to 6.52-fold increased risk for type 2 diabetes in the two study groups (families P = 0.025, urban survey P = 0.015). A combination of the 1112 haplotype with the 1221 haplotype also appeared to increase risk for both IFG/IGT and type 2 diabetes. Contrary to what might be expected, quantitative trait analysis in the families found that transmission of the disease-related 1121 and 1112 haplotypes was associated with a reduced hip size and lower waist-to-hip ratio, respectively. This study supports the paradigm that specific haplotype combinations of calpain 10 variants increase risk of both IFG/IGT and type 2 diabetes. However, the relative infrequency of the "at-risk" combinations in the South Indian population suggests that calpain 10 is not a common determinant of susceptibility to type 2 diabetes.

Adult↗