Glutaric Acidemia Type 1: Diagnosis, Clinical features, and Outcome in a Portuguese Cohort.

INTRODUCTION: Glutaric acidemia type 1 (GA1) is a rare autosomal recessive disorder characterized by a deficiency of glutaryl-CoA dehydrogenase, resulting in the accumulation of glutaric acid (GA), 3-hydroxyglutaric acid, and glutarylcarnitine, especially in the brain. GA1-affected children are clinically characterized by macrocephaly. Neurological abnormalities usually appear between 6 and 18 months of age, often triggered by a catabolic event. On the other hand, several biochemically affected individuals may remain asymptomatic or experience an insidious onset of mild neurological abnormalities. METHODS: Retrospective study of GA1 patients followed at a Portuguese Hereditary Metabolic Disease Center, to characterize the phenotypic and genotypic variations associated with GA1. Therefore, we analyzed the clinical, neuroradiological, biochemical, and genetic information from 14 patients. RESULTS: 14 patients (four months-27 years old) were identified in the last 26 years, 9 were male, 1 was from a consanguineous family. 11 were diagnosed by newborn screening (NBS), and 3 identified following clinical symptoms (later diagnosed, LD). There were 3 phenotypic presentations: 6 asymptomatic, 3 with a motor disability after encephalopathic crisis (EC), and 5 with insidious onset. Acute EC occurred in 1/3 of the LD patients and in 2/11 NBS-identified patients. About urinary GA concentrations: 5 were low excretors (LE), 9 were high excretors (HE). All LE showed symptoms, and 2 had EC. Concerning HE, 3 showed symptoms and 1 had EC. GCDH analysis showed: 6 compound heterozygotes and 8 homozygotes. most frequent variant was c.1204C>T (p.R402W). All of them received appropriate therapy from the time of diagnosis, with a mean age of 23.3 months in LD patients and 13.3 days in NBS-identified patients. CONCLUSION: The outcomes were different between the two groups: all the LD patients presented motor dysfunction however in the NBS-identified patients only 5 developed this symptom. Patients identified by NBS had better outcomes showing that NBS enables an early diagnosis, and treatment, and consequently improves the clinical outcomes for these patients. No correlation was observed with clinical phenotype between LE and HE, as both groups can suffer the most severe neurological manifestations. These conclusions are in agreement with previous cohorts described in the literature.

Clinical and Nutritional Evolution of 24 Patients with Glutaric Aciduria Type 1 in Follow-up at a Center Specialized in Inborn Errors of Metabolism in Chile

Abstract Introduction: Glutaric Aciduria Type 1 (GA-1) is produced by the enzymatic deficiency of glutaryl-CoA-dehydrogenase (GCDH), leading to the accumulation of glutaric acid (GA). 90% of patients without early treatment present acute encephalopathic crisis (AEC), followed by disabling neurological symptoms. The treatment consists of a low lysine (Lys) diet, protein substitute lys-free, tryptophan-reduced (PS) and L-carnitine. Objectives: Describe the clinical and nutritional evolution of a cohort of GA-1 patients at a national referral center in Chile. Methodology: Retrospective study of 24 patients diagnosed with GA-1 between 1998-2020 and referred to the Institute of Nutrition and Food Technology (INTA) of University of Chile. Results: Age at diagnosis was 19±27 months; 10/24 presented AEC and neurological sequelae. The cases without AEC (14/24) 8 presented neurological compromise: psychomotor development delay, abnormal movements and pyramidal syndrome. Nutritional evaluation: 12/24 were malnourished by deficiency, <6 years old group (12/24): 11 cases were found to have Lys and PS, ≥6 years old (12/24): 9/12 did not receive PS. All had normal free carnitine levels. Conclusion: GA-1 has variable symptoms with neurological involvement AEC or insidious start. Is essential to maintain a long-term follow-up and consider its inclusion in neonatal screening programs.

Anesthetic Management for Fracture Head of Radius in a Child with Glutaric Aciduria type-1.

Glutaric aciduria Type 1 (GA-1) is an autosomal recessive metabolic disorder that results from deficiency of enzyme glutaryl-CoA dehydrogenase. This gives rise to elevated neurotoxic glutaric acid and 3-hydroxyglutaric acid as well as nontoxic glutarylcarnitine in body fluids. The enzyme defect leads to secondary damage to central nervous system due to the accumulation of glutaric acid. Approximately 90% people will develop the neurological disease during a finite period of brain development (3-36 months) following an acute encephalopathic crisis often precipitated by gastroenteritis, immunization, surgical intervention, and intercurrent febrile illness. GA-1 can also develop insidiously without clinically apparent crisis in 10%-20% of the patients. We present a 10-year-old male child with GA-1 who required anesthetic care for fracture (left) neck of radius. Strategies for anesthetic management should include prevention of hypoglycemia, dehydration, electrolyte imbalance, and sufficient analgesia to prevent surgical stress.

MRS features during encephalopathic crisis period in 11 years old case with GA-1.

Glutaric aciduria type-1 (GA-1) is a disorder of amino acid metabolism. The usual clinical-onset is an acute encephalopathic crisis in early childhood. There are only a few cases diagnosed in older age groups. MRI features of the disease are well defined. However, there are limited number of studies concerning advanced neuroimaging findings. We present DWI and MRS findings of an 11 year-old GA-1 patient admitted with an encephalopathic crisis. Diffusion restrictions in bilateral basal ganglia, corpus callosum and periventricular deep white matter were observed. In left occipital periventricular white matter and left basal ganglia, mild increased Cho/Cr and MI/Cr ratios and decreased NAA/Cr ratio were detected. Also inverted double lactate peak (TE: 135 ms) was present at 1.33 ppm in the left basal ganglia. In addition to these findings, a peak at 1.56 ppm above the baseline was seen on both short and long echo-time MRS in left occipital lobe deep white matter which may show accumulation of degradation products of amino acids in the GCDH enzyme deficiency.