Practical aspects of therapy for glutaric aciduria type 1

Treatment of many of the diseases in the panel of expanded newborn screening includes dietary therapy. Glutaric aciduria type 1 (GA1) is a hereditary disorder caused by mutations in the gene GCDH, encoding glutaryl‑CoA dehydrogenase, an enzyme in the amino acid metabolic pathways. The decreased activity of the enzyme leads to accumulation of neuro‑ toxic metabolites. The recommended treatment approaches for GA1 are the prescription of specialized nutrition products, levocarnitine, and symptomatic management. In 2021, clinical guidelines for the treatment of this rear disease were published in Russian Federation. To provide for the timely treatment, it is essential for a practitioner involved in the care patients with such a rare disorder as GA1 to have the knowledge of the principles of management, as well as practical algorithms for diet calculation.The article gives a detailed case‑based description of management during metabolic decompensation and the choice of dietary therapy for GA1 patients of different age groups.

The biochemical subtype is a predictor for cognitive function in glutaric aciduria type 1: a national prospective follow-up study

The aim of the study was a systematic evaluation of cognitive development in individuals with glutaric aciduria type 1 (GA1), a rare neurometabolic disorder, identified by newborn screening in Germany. This national, prospective, observational, multi-centre study includes 107 individuals with confirmed GA1 identified by newborn screening between 1999 and 2020 in Germany. Clinical status, development, and IQ were assessed using standardized tests. Impact of interventional and non-interventional parameters on cognitive outcome was evaluated. The majority of tested individuals (n = 72) showed stable IQ values with age (n = 56 with IQ test; median test age 11 years) but a significantly lower performance (median [IQR] IQ 87 [78–98]) than in general population, particularly in individuals with a biochemical high excreter phenotype (84 [75–96]) compared to the low excreter group (98 [92–105]; p = 0.0164). For all patients, IQ results were homogenous on subscale levels. Sex, clinical motor phenotype and quality of metabolic treatment had no impact on cognitive functions. Long-term neurologic outcome in GA1 involves both motor and cognitive functions. The biochemical high excreter phenotype is the major risk factor for cognitive impairment while cognitive functions do not appear to be impacted by current therapy and striatal damage. These findings implicate the necessity of new treatment concepts.

Glutaric Aciduria Type 1 ; Does it Effect of Hearing Function?

The main objective of this study was to observe the audiological findings of patients with Glutaric Aciduria Type 1 (GA-1), which is very difficult to evaluate and diagnose due to limited scientific literature. We used an audiological test battery to evaluate the study group of 17 individuals with GA-1 diagnosis and the control group of 20 healthy individuals. Following the otoscopic examination, the audiological test battery consisting of pure-tone hearing threshold (PTA) test, immittancemeter, distortion product otoacoustic emissions (DPOAE), contralateral suppression of otoacoustic emissions, and auditory brainstem response (ABR) measurements were applied to all participants (N=37).DPOAE amplitudes and the contralateral distortion product suppression values were significantly lower in the study group compared to control group (p < 0,05). In the study group, although they had a normal hearing level, there were morphologically different ABR waves than the control group, which was considered a remarkable finding. As well as I-V interpeak latency, the absolute latencies of I, III, and V waves ABR of the study group, were observed to be prolonged significantly compared to the control group (p < 0,05). Our findings support that GA-1 disease of association with auditory damage. The use of otoacoustic emissions and ABR measurements in the audiological test battery would be useful tool in the early diagnosis and follow-up of hearing sensivity individuals with GA-1.

Glutaric aciduria type 1 in children. Clinical presentation of 46 cases in Russian families

Background. Glutaric aciduria type 1 is an autosomal recessive disease caused by mutations in the GCDH gene, which encodes the enzyme glutaryl‑CoA dehydrogenase. Metabolic crisis in type 1 glutaric aciduria is an acute life‑threatening condition that requires careful diagnosis with a number of other conditions and the immediate initiation of pathogenetic therapy.Materials and methods. Clinical manifestations, neuroimaging characteristics of the disease were studied in 46 patients with diagnosed glutaric aciduria type 1 confirmed by biochemical and molecular genetic methods. Methods: gas chromatography with mass spectrometry, tandem mass spectrometry, Sanger sequencing, chromosomal microarray analysis of the exon level.Results and discussion. A retrospective analysis of anamnestic and clinical data was carried out, and the nature and age of disease manifestation, provoking factors, a spectrum of clinical manifestations and neuroimaging data were assessed.Conclusion. How initiated treatment prevents progression of neurological symptom relief and patient adaptation. With the help of the goal, it is necessary to inform pediatricians, neurologists and neuroradiologists about this feature of the course of glutaric aciduria type 1 in order to increase the clinical alertness of this disease.

COVID-19 triggered encephalopathic crisis in a patient with glutaric aciduria type 1

Objectives The impact of coronavirus disease-19 (COVID-19) on metabolic outcome in patients with inborn errors of metabolism has rarely been discussed. Herein, we report a case with an acute encephalopathic crisis at the course of COVID-19 disease as the first sign of glutaric aciduria type 1 (GA-1). Case presentation A 9-month-old patient was admitted with encephalopathy and acute loss of acquired motor skills during the course of COVID-19 disease. She had lethargy, hypotonia, and choreoathetoid movements. In terms of COVID-19 encephalopathy, the reverse transcription-polymerase chain reaction assay test for COVID-19 was negative in cerebral spinal fluid. Brain imaging showed frontotemporal atrophy, bilateral subcortical and periventricular white matter, basal ganglia, and thalamic involvement. Elevated glutarylcarnitine in plasma and urinary excretion of glutaric and 3-OH-glutaric acids was noted. A homozygote mutation in the glutaryl-CoA dehydrogenase gene led to the diagnosis of GA-1. Conclusions With this report, neurological damage associated with COVID-19 has been reported in GA-1 patients for the first time in literature.

Evaluation of the Clinical, Biochemical, Neurological, and Genetic Presentations of Glutaric Aciduria Type 1 in Patients From China

PurposeTo characterize the phenotypic and genotypic variations associated with Glutaric aciduria type 1 (GA1) in Chinese patients.MethodsWe analyzed the clinical, neuroradiological, biochemical, and genetic information from 101 GA1 patients in mainland China.Results20 patients were diagnosed by newborn screening and the remaining 81 cases were identified following clinical intervention. Macrocephaly was the most common presentation, followed by movement disorders and seizures. A total of 59 patients were evaluated by brain MRI and 58 patients presented with abnormalities, with widening of the sylvian fissures being the most common symptom. The concentration of glutarylcarnitine in the blood, glutarylcarnitine/capryloylcarnitine ratio, and urine levels of glutaric acid were increased in GA1 patients and were shown to decrease following intervention. A total of 88 patient samples were available for genotyping and 74 variants within the GCDH gene, including 23 novel variants, were identified. The most common variant was c.1244-2A &gt; C (18.4%) and there were no significant differences in the biochemical or clinical phenotypes described for patients with the four most common variants: c.1244-2A &gt; C, c.1064G &gt; A, c.533G &gt; A, and c.1147C &gt; T. Patients identified by newborn screening had better outcomes than clinical patients.ConclusionOur findings expand the spectrum of phenotypes and genotypes for GA1 in Chinese populations and suggest that an expanded newborn screening program using tandem mass spectrometry may facilitate the early diagnosis and treatment of this disease, improving clinical outcomes for patients in China.