Biomedical subjects

Mårten Jansson

Publications and source records attributed to Mårten Jansson.

3 recordsLinked to original sources

PubMed2006

Longitudinal change in memory performance associated with HTR2A polymorphism.

We present a fresh approach to evaluating association with candidate genes and cognitive change by testing association for parameters describing individual growth curves from twins. Moderate genetic influences on memory in aging adults has been shown in quantitative genetic studies. A recently reported, association of a HTR2A polymorphism with episodic memory in young unrelated adults led us to investigate the association between a nearby polymorphism and longitudinal memory performance in the Swedish Adoption/Twin Study of Aging (SATSA). Analysis of growth curve parameters suggests that both how well individuals perform on figural memory at age 65 years and nonlinear change in figural memory performance across age are associated with HTR2A. Individuals with two copies of the common G allele demonstrated higher figural memory performance longitudinally than those with the less frequent A allele, with performance trajectories differing by 2-6% per year. These findings imply a role for the 5-HT2A serotonin receptor on the formation of episodic memories in older adults.

Age Distribution↗

PubMed2005

MAOA haplotypes associated with thrombocyte-MAO activity.

BACKGROUND: The aim was to ascertain whether thrombocyte MAO (trbc-MAO) activity and depressed state are genetically associated with the MAO locus on chromosome X (Xp11.3 - 11.4). We performed novel sequencing of the MAO locus and validated genetic variants found in public databases prior to constructing haplotypes of the MAO locus in a Swedish sample (N = 573 individuals). RESULTS: Our results reveal a profound SNP desert in the MAOB gene. Both the MAOA and MAOB genes segregate as two distinct LD blocks. We found a significant association between two MAOA gene haplotypes and reduced trbc-MAO activity, but no association with depressed state. CONCLUSION: The MAO locus seems to have an effect on trbc-MAO activity in the study population. The findings suggest incomplete X-chromosome inactivation at this locus. It is plausible that a gene-dosage effect can provide some insight into the greater prevalence of depressed state in females than males.

Blood Platelets↗

PubMed2002

Large-scale genotyping of single nucleotide polymorphisms by Pyrosequencingtrade mark and validation against the 5'nuclease (Taqman((R))) assay.

Here we present the first large-scale effort at genotyping using a novel sequencing method, Pyrosequencingtrade mark, as a method for genotyping of single nucleotide polymorphisms (SNPs). Pyrosequencingtrade mark genotypes were validated through duplicate analysis of 1,022 genotypes using the PSQ96trade mark instrument for pyrosequencing and TaqMan((R)) for 5'nuclease assays. Identical results were obtained using both methods. In a small pilot study, a pooling strategy using Pyrosequencingtrade mark was successfully tested. We conclude that Pyrosequencingtrade mark is highly efficient and accurate in the analysis of SNPs and represents a promising solution to high-throughput genotyping of large sample populations.

Alleles↗