To longitudinally monitor a child with glutaric acidemia type 1: a case report

*Correspondence: [e-mail].

Abstract

Case Presentation: This case report describes a genetic disease, Glutaric acidemia type 1, that can cause significant neurological impairment when left untreated. A female child with no previous complications experienced her first epileptic seizure at the age of 2 after receiving the influenza vaccine. After this, she experienced a regression in neuropsychomotor development. Magnetic resonance imaging (MRI) of the brain showed signs of cytotoxic edema, and a suspicion of Inborn Errors of Metabolism (IEM) was raised. Urine organic acid analysis revealed increased levels of 3-hydroxy-glutaric acid. Molecular testing confirmed the diagnosis of glutaric acidemia type 1 (GCDH; c.92+5 G>A in homozygosity). The patient started on a diet with lysine restriction and supplementation with L-Carnitine and Riboflavin. The patient discontinued dietary and medical treatment at the age of 3 but returned for follow-up at the age of 5, with complaints of learning difficulties. On clinical examination, she exhibited athetosis, spasticity, and Babinski extension on the left. MRI showed areas of altered signal in the white matter. Neuropsychological evaluations performed at age 7 revealed a normal IQ and no impairment in attention or academic performance.

Discussion: Glutaric acidemia type 1 (GA1) is an autosomal recessive metabolic disorder that causes an increase in glutaric and 3-hydroxyglutaric acids. MRI typically shows frontotemporal atrophy and hypersignal in the dentate nucleus. Symptoms usually begin at 3 months of age with a progressive increase in head circumference, hypotonia, irritability, and feeding difficulties. Develop encephalopathy, developmental regression, movement disorders, with or without epileptic seizures.

Final Comments: In this case report, due to the COVID-19 pandemic, the patient's family was unable to continue her treatment. It would be expected that the patient would exhibit neurological decline after 2 years without treatment, but at age 7, she showed no neurocognitive decline. The principles of treatment aim to restrict lysine and supplement it with carnitine and riboflavin. The need for dietary interventions beyond early childhood is uncertain. Despite early diagnosis and treatment, patients may exhibit reduced fine motor skills and are at risk of developing speech and language difficulties. Regardless of IQ scores, executive functioning, attention, gross motor skills, and visual memory are usually in the average or above-average range.