Newborn screening of homocystinuria: quantitative analysis of total homocyst(e)ine on dried blood spot by liquid chromatohraphy with fluorimetric detection

Identification of homocystinuric newborn is hindered by the pitfalls of neonatal sceening programs. We propose a fluorimentric HPLC method with a rapid pre-analytica step for homocysteine determination from neonatal dried blood spot cards. Homocysteine in blood spots sampled among 2000 healthy newborns on living day 4, averaged 2.92 ± 2.07 mM (range 0.4-7.5). In eight homocystinuric control children, mean values were 61.71 ± 52.84 mM (range 18.9-145.7). The method showed a good linearity (r = 0.999), precision (RDS<7%) and recovery (95%). The correlation between blood spots and rapid pre-analytical step combined with method linearity and precision.