Association between ADAM33 polymorphisms and asthma in a Thai population.

ADAM33 (A Disintegrin And Metalloprotease 33) is an asthma susceptibility gene found across several human populations. However, no information on ADAM33 exists for Thai population. The objective of this study was to determine the association, if any, between ADAM33 polymorphisms and asthma in Thai subjects. Genotyping revealed 8 single nucleotide polymorphisms (SNPs) within the 3' region of the ADAM33 gene among 200 asthmatics and 100 control subjects. Asthmatic subjects were further sub-categorized into high and low severity groups. Multiple genetic model statistic tests for single-marker and haplotype association were carried out. Differences in allele frequencies at the SNPs rs528557/S2, rs598418 and rs44707/ST+4 in asthmatics were statistically significant compared to controls. The SNP rs528557/S2 could also be linked to the low severity group and the SNPs rs598418 and rs44707/ST+4 with the high severity group. Two-SNP haplotype analysis at the SNPs rs528557/S2 and rs598418 revealed a significant association with asthma. This study in a Thai population confirmed a positive association between ADAM33 polymorphisms and asthma susceptibility.

Preimplantation Genetic Diagnosis for alpha thalassemia: experience in Siriraj Hospital.

Objective: Detection of fetal thalassemia using preimplantation genetic diagnosis (PGD) can make a diagnosis before pregnancy so termination of pregnancy in that patient is eliminated. The objective of this study was to develop a single gene polymerase chain reaction (PCR) protocol for PGD of alpha thalassemia in Siriraj Hospital. Methods: A couple with a history of repeated Bart’s hemoglobinopathy in fetus underwent an artificial reproductive technique (ART) process using a standard ovarian stimulation protocol with intracytoplasmic sperm injection (ICSI) to reduce sperm DNA contamination. On day 3 post fertilization, laser biopsy was performed on the cleavage stage embryos to obtain a blastomere for PCR analysis of alpha thalassemia 1 SEA type. Results: 11 embryos from a total of 15 oocytes were biopsied, 2 normal, 1 alpha thal 1 trait and 3 affected embryos were detected. No contamination and allele drop out were detected, but a high PCR failure rate of 5 from 11 total biopsied embryos. Conclusion: PGD for alpha thalassemia was first established in Siriraj Hospital, but the result had a high failure rate so then optimized laboratory techniques were required.