185

AGTR1

AG2S|AGTR1A|AGTR1B|AT1|AT1AR|AT1B|AT1BR|AT1R|AT2R1|AT2R1A|AT2R1B|HAT1R;angiotensin II receptor, type 1;AGTR1;angiotensin II receptor, type 1

type-1 angiotensin II receptor|type-1B angiotensin II receptor

3q24

protein-coding

Count: AGTR1; 185

BACKGROUND/PURPOSE: The renin-angiotensin system plays an important role in pulmonary artery remodelling. Several polymorphisms of genes encoding for components of the renin angiotensin system such as the angiotensin converting enzyme (ACE), the angiotensinogen (AGT) gene, and the angiotensin II type 1 receptor (ATIR) have been associated with the development of pulmonary hypertension. The aim of this study was to investigate the ACE I/D genotype, the M235 T polymorphism of the AGT gene and the A1166 C polymorphism of AT1R in the lungs of congenital diaphragmatic hernia (CDH) complicated by persistent pulmonary hypertension (PPH) in the newborn. METHODS: Genomic DNA was extracted from archival paraffin-embedded lung tissue from 13 newborns with CDH complicated by PPH and from 9 controls. Genotyping for the I/D-ACE, the M235 T-AGT, and the A1166 C-ATIR gene polymorphisms were determined by a polymerase chain reaction-based method with appropriate restriction digest when required. RESULTS: In controls, ACE genotype distribution of DD, ID, and II was 11%, 33%, and 55%, respectively, whereas in CDH it was 70%, 15%, and 15%, respectively. The ACE-DD genotype was significantly higher in CDH compared with controls (P <.05). In CDH samples, the prevalence of AGT-MM genotype was lower (8% v. 33%; P <.05), whereas the AGT-TT genotype was higher (61% v. 22%; P <.05) compared with controls. There were no differences in allele frequencies of AT1R between CDH patients and controls. CONCLUSIONS: These data suggest that D allele of the ACE gene insertion/deletion polymorphism and angiotensinogen M235 T polymorphism may be associated with PPH in newborns with congenital diaphragmatic hernia.

BACKGROUND: pulmonary arterial hypertension (PAH) is a rare, lethal disease associated with single gene disorders, connective tissue disease, exposures to anorexigens, and often, idiopathic etiology. Genes can modify the risk of PAH: (1) monogenic disorders associated with PAH are incompletely penetrant, and (2) not all patients with associated conditions at increased risk for PAH develop the disease. The renin angiotensin aldosterone system (RAAS) provides a set of candidate genes that could modulate pulmonary vascular disease similar to its effects on renal and peripheral vasculature. METHODS: We studied 247 patients with PAH, comprising 177 with idiopathic PAH (IPAH), 63 with PAH/connective tissue disease (CTD), and 7 with PAH associated with anorexigens. Patients were genotyped for 5 common polymorphisms in angiotensinogen (AGT), angiotensin-converting enzyme (ACE), cardiac chymase A (CMA1), angiotensin II type 1 receptor (AGTR1), and aldosterone synthase (CYP11B2). Genotypes were tested for associations with age at diagnosis, hemodynamic parameters at diagnosis, and/or response to acute pulmonary vasodilator testing at diagnosis. RESULTS: Associations were demonstrated for AGTR1 and age at diagnosis in IPAH (p = 0.005). Homozygotes for the 1166C allele (n = 13) were associated with an age at diagnosis 26 years later than those with A/A (n = 139) or A/C (n = 90) genotypes. No associations were demonstrated for AGT, ACE, CMA1, or CYP11B2. CONCLUSIONS: The 1166C polymorphism in AGTR1 appears to be associated with a later age at diagnosis in IPAH, suggesting that this pathway could be involved in the biologic variability that is known to occur in PAH.