The present invention relates to a method and kit for identifying a subject having or at risk of having or developing an isolated neonatal systemic hypertension (NSH) and/or NSH associated cardiogenic shock, comprising determining, in a sample obtained from said subject, the presence or absence of bi-allelic nucleotide variants (NV) located in NPR1 gene, said NV predicted to be pathogenic and being associated with NPR1 loss of function. The present inventors have established a statistical link between specific predicted pathogenic variants located in the NPR1 gene and neonatal systemic hypertension (NSH) in a cohort of NSH disease families. More precisely, the present inventors have established a link between specific predicted biallelic pathogenic variants contained in NPR1 in patients with NSH and/or cardiogenic shock (in multiplex and consanguineous families) associated sometime with increased Nuchal Translucency (NT). Another object of the invention relates to a method for treating neonatal systemic hypertension (NSH) and/or NSH associated cardiogenic shock.