The haplotype (CCTTT)14/TT, formed by the expansion of the − 2.5 kb (CCTTT)n microsatellite in the NOS2A gene promoter and the -511 C➝ T SNP of the IL-1β gene promoter, might be a useful marker to identify patients who are at high risk for developing CP after hypoxic-ischemic encephalopathy. Here, NOS2 is linked to perinatal asphyxia.