Glutaric Aciduria Type 1 in Poland Detected Through Newborn Screening – Incidence, Initial Management and Outcome

In glutaric aciduria type 1 (GA1), quick initiation of treatment of asymptomatic infants detected by newborn screening (NBS) improves their outcome.

This is a retrospective study of 15 patients born between 2015 and 2022 detected by NBS with suspected GA1, which was confirmed by GC/MS and DNA. Initial management covers the first two years, the vulnerable period in GA1.

GA1 incidence in Poland is 1:139000. Macrocephaly was observed in 4 newborns. The mean C5DC in DBS was 0.83 µmol/l (0.23−1.82). The GC/MS urinary profile showed high excretion of GA and 3-OH-GA acids in all cases. A low-lysine diet and carnitine supplementation were introduced in the 1st month of life in all but one (at 60 days old) patient. All patients were treated with carnitine (ca 100 mg/kg/d; adjusted to their current b.w.). Breastfeeding (BF) together with special formula was possible during the neonatal period in 80% of cases, 53% at 3 months but only 20% of infants at 6 months. The mean daily energy intake was 88.8 kcal/kg in their infantile period and 1084 kcal at 2 years old. In the first year of life, the mean daily natural, equivalent protein and lysine intake were: 1.088 g/kg, 0.85 g/kg and 80.64 mg/kg, respectively. At 2 years, they were as follows: 0.925 g/kg, 0.87 g/kg and 54.9 mg/kg, respectively. The follow-up period in 12 patients was 10 months to 8 years. No encephalopathic crises were noted. Normal, borderline and delayed intellectual development was observed in 8, 2 and 3 patients, respectively, but without regression and 2 boys presented signs of the autistic spectrum. Dystonic movements occurred in 1 patient and macrocephaly in 2 cases.

The calculated GA1 incidence in Poland is relatively lower than reported elsewhere. Prompt initial management (including BF) and regular monitoring of intake of energy, natural and equivalent protein and lysine result in favourable outcomes. Most patients remain asymptomatic but all require careful metabolic, neurologic, psychologic and dietetic control.