Possible association between a polymorphism of EPAS1 gene and persistent pulmonary hypertension of the newborn: a case-control study

Abstract Objective: To explore possible genes related to the development of persistent pulmonary hypertension of the newborn (PPHN). Methods: The authors identified 285 single nucleotide polymorphisms (SNPs) of 11 candidate genes (BMPR2, EPAS1, PDE3A, VEGFA, ENG, NOTCH3, SOD3, CPS1, ABCA3, ACVRL1, and SMAD9), using an Illumina Asian Screening Array-24 v1.0 BeadChip Array. The FastLmmC and R package was used for statistical analyses. The chi-square test and Cochrane-Armitage trend test were used to compare the allele and genotype frequencies between the groups and to test the genetic models, respectively. Results: A total of 45 PPHN infants and 294 control subjects were analyzed. The most common cause of PPHN was meconium aspiration syndrome. Among the 285 SNPs, 17 SNPs from 6 candidate genes (BMPR2, EPAS1, PDE3A, VEGFA, ENG, and NOTCH3) were significantly associated with PPHN (P < 0.05). After using the Bonferroni correction (P < 0.00018), only the rs17034984 SNP located in intron 1 of the EPAS1 gene remained significantly different between the PPHN and control subjects (P = 0.00014). The frequency of the TC/TT genotype of rs17034984 in the gene with the dominant model was significant in the patients with PPHN (OR = 5.38, 95% CI: 2.15-13.49). The T allele frequency of rs17034984 in the gene showed a significant difference compared with the control subjects (OR = 4.89, 95% CI: 2.03-11.82). Conclusions: The present study suggests that the rs17034984 variant of EPAS1 gene is associated with PPHN.

Multiplex methylation specific PCR analysis of fragile X syndrome: experience in Songklanagarind Hospital.

Methylation specific PCR (MS-PCR) is a technology for a sensitive detection of methylation in the gene. This assay was developed for diagnosis of methylation-related diseases including fragile X syndrome (FXS), the most common X-linked mental retardation caused by a CGG trinucleotide repeat expansion. Affected individuals (full mutation, FM) have CGG greater than 200 repeats, while normal individuals and premutation (PM) carriers have 6-54 and 55-200 repeats, respectively. Only FM individuals are correlated with methylation of the gene. The authors tested this assay on known 35 DNA samples (15 normal, 2 PM and 18 FM) and a prospective study of 60 males referred for FXS screening in Songklanagarind hospital. In addition, the authors tested on 2 prenatal cases. All results were corresponded to PCR for CGG repeats and/ or Southern blot analysis. The authors concluded that MS-PCR provides an accurate method for methylation detection of FXS.