Detection of other inborn errors of metabolism in hyperphenylalaninemic babies picked up on narrow-spectrum screening programs

In many countries, neonatal screening programs have been unable to expand and have been limited to a few diseases. We highlight herein the opportunity available for the early detection of some inborn errors of metabolism (IEMs) in those countries in which newborn screening programs are limited. All the newborns that are referred to us for hyperphenylalaninemia are examined physically and their blood samples are checked by both high-performance liquid chromatography (HPLC) for blood phenylalanine levels and by amino acid analyzer for the measurement of blood amino acid concentrations. Seven patients who had been referred to our unit for hyperphenylalaninemia were eventually diagnosed with another IEM. A careful physical examination of the babies sent for positive screening test result combined with the utilization of low expense screening techniques at the experienced referring centers might facilitate otherwise missed opportunities for the early detection of some IEMs.