Association between polymorphisms in the P2RY1 and SSTR2 genes and sudden infant death syndrome

Abstract

Sudden infant death syndrome (SIDS) is a multifactorial syndrome and we believe that an inefficient respiratory response to certain homeostatic stressors, such as hypoxia and hypercapnia, is a key factor in the etiology of SIDS. Hence, we genotyped two single nucleotide polymorphisms (SNPs) in genes of importance for respiratory control: P2RY1 (adenosine diphosphate/adenosine triphosphate receptor) and SSTR2 (somatostatin receptor). Two SNPs, Rs1466113 (C > G dimorphism in SSTR2) and rs701265 (A > G dimorphism in P2RY1), were typed in 175 SIDS cases and 195 controls and 275 SIDS cases and 338 controls, respectively. Genotyping was performed using TaqMan technology. The determined genotype frequencies were SSTR2: CC (14.4%), CG (49.7%), GG (35.9%) in controls and CC (17.1%), CG (49.1%), and GG (33.8%) in SIDS; P2RY1: AA (70.6%), AG (28.7%), GG (0.7%) in SIDS and AA (68.3%), AG (27.9%), and GG (3.8%) in the control group. For rs701265 in P2RY1, homozygous G carriers were significantly more frequent in the control group (p = 0.02). We think that allele G provides a protective effect in events of ventilatory stress. Moreover, the significant lack of P2Y1 G allele homozygotes in the SIDS group shows that respiratory response plays an important role in the etiology of SIDS. Thus, we believe it is worthwhile to further investigate functional polymorphisms within genes that are involved in respiratory control in the future.