Genetic polymorphisms

Cindy Zuluaga RamírezMedicine studentMolecular Biology

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INTRODUCTION

Variotion in regulatory DNA is what we call

Polymorphism.

This is one of the ways in wich we can detect

Polymorphisms.

Cross-Species Strategy Might Be a Powerful Tool for Studying Human Disease

ScienceDaily (Feb. 4, 2011)

Cross –species strategy

Specifically, the researchers evaluated 19 genes from 15 distinct genomic regions identified in a human GWAS designed to identify genes that influence Alzheimer´s disease pathology.

FINDINGS IN THE TECHNIQUE

In six out of these 15 genomic regions, a causal gene was subsequently identified in the fly disease model on the basis of interactions with the neurotoxicity of Tau protein, a well-known constituent of AD pathology.

OBSERVATIONS

I think that this technique is a huge improvement for genetic studies, since scientists are taking information from some other species in wich we could find some genetic similarities in some diseases and making new finds of the genetic basis of the disorder and get some new treatments .

Genes That Link Nephritis to Autoantibodies and Innate Immunity

THE NEW ENGLAND JOURNAL OF MEDICINE (FEBRUARY 17,2011)

FINDINGS

• The annual incidence of membranous nephropathy is approximately 1 case per 100,000 population.

• The results reported by Stanescu et al. confirm the findings of two recent studies from Asia (Taiwan and Korea) that used a candidate gene approach. Both those studies examined only SNPs in the PLA2R gene that resulted in amino acid changes, and a significant association was found for one SNP.

• Although a relation between the HLA system and membranous nephropathy has been recognized for some time, the knowledge of an association between this disease and PLA2R is recent. In 2009, Beck and colleagues reported autoantibodies with specificity for PLA2R that were present in 70% of their patients with idiopathic membranous nephropathy but not in controls or patients with secondary membranous nephropathy. These results are now confirmed and extended in a letter by Debiec and Ronco in this issue of the Journal.

The SNP in the PLA2R gene with the strongest association does not alter the amino acid

sequence

the true association might not be with rs4664308 but rather with rs3749117, which is a nonsynonymous SNP reported to be in linkage disequilibrium with rs4664308. If so, the higher odds ratios in all three cohorts would have occurred at random.

The rs4664308 might be a marker for a rare variation in the protein sequence, below the threshold required to be considered a SNP. This putative variant would then confer a very high risk of disease for its carriers.

Two possible theories

CONCLUSSION

In summary, this new genomewide association study highlights the interaction between the HLA system and the receptor for sPLA2 and provides substantial credence for a pathogenic role for the recently discovered autoantibodies in membranous nephropathy. It may redirect research toward finding a remedy for this troublesome disease.

OBSERVATIONS

I think this new discovery will make easier the diagnosis of idiopathic membranous nephropathy making karyotype and searching changes among the alleles implicated in this disorder that encode HLA-DQA1 and the M-type phospholipase A2 receptor.

MEDICAL UTILITY

MEDICAL UTILITY

Early diagnosis

Easy identification of the patients in risk

Early and quick begining of treatment

Improvement in the life

quality of the patients

For the development and the sustentation of genetic studies .

BIBLIOGRAPHY

• N Engl J Med 2011; 364:679-680; http://www.nejm.org/doi/full/10.1056/NEJMe1014144

• http://www.sciencedaily.com/releases/2011/02/110203124712.htm

• STRACHAN, Tom. Human molecular genetics , 2004. 3.ed. Garland science

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