China’s newborn screening (NBS) system, initiated over four decades ago with dual-disease detection [phenylketonuria (PKU) and congenital hypothyroidism (CH)], has progressively expanded to encompass congenital adrenocortical hyperplasia (CAH) and glucose-6-phosphate dehydrogenase (G6PD) deficiency, achieving nationwide universal coverage. The gene discussed is G6PD; the disease is phenylketonuria.