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To evaluate the pathogenic variants in GCDH gene and to assess the neurodevelopmental outcomes in children with Glutaric aciduria type 1 (GA-1). Cross-sectional observational study between January 2019 and June 2020 in consecutive North Indian children with a clinical and biochemical suspicion of GA-1. Variants in the coding regions of GCDH gene were identified through Sanger sequencing. Neurodevelopmental and quality of life assessment was done using standardized scales. 24 children with GA-1 were identified. The median age at diagnosis was 12 months and the median delay in diagnosis was 3 months. Genetic analysis was done in 14 cases. It revealed 12 variants (11 missense and one nonsense) from 13 patients. Most of the pathogenic variants were in exon 9 and exon 5. Three novel variants were identified in three patients: two missense variants c.169G > A (p.Glu57Lys), c.1048T > C (p.Cys350Arg) and one nonsense variant c.331C > T (p.Lys111Ter). On neurodevelopmental assessment, majority of children with GA-1 were non ambulatory (62.5%), had limited hand skills (58.3%) and impaired communication (58.3%). Overall, poor global development was noted in 43.7%. A pre-existing developmental delay was significantly associated with impaired communication skills (p = 0.03), and the number of episodes of encephalopathy were significantly associated with impaired gross motor skill (p = 0.02). Presence of encephalopathy was significantly associated with poor performance in social emotional (p = 0.01) and cognitive (p = 0.03) domains of Developmental Profile-III scale and development of severe dystonia (p = 0.01). Our findings highlight the clinical, biochemical, radiological and genetic spectrum of GA-1 in children in North India and report the presence of novel pathogenic variations. • Identification of exon 9 and 5 as hotspots in the GCDH gene in North Indian children. • Identification of three novel pathogenic variations. • Detailed neurodevelopmental and quality of life assessment. • Identification of predictors of poor neurodevelopmental outcomes. [ABSTRACT FROM AUTHOR]

Nutritional deficiencies related neurological manifestations are not uncommon in infants and children. Here, we describe an infant with Vitamin B12 deficiency due to depleted maternal Vitamin B12 status presenting with progressive encephalopathy and extrapyramidal signs. Diagnosis of infantile tremor syndrome was established in our patient based on the clinical and biochemical parameters. Magnetic resonance imaging had shown frontotemporal atrophy with widened Sylvian fissures and prominent cerebrospinal fluid spaces. Clinical and imaging findings might create a diagnostic dilemma with glutaric aciduria type I. Knowledge and identification of infantile tremor syndrome are essential, as it is a potentially treatable disorder. Our patient had significant developmental gains with Vitamin B12 treatment and infant stimulation program. Vitamin B12 deficiency must be looked for as a cause of neuroregression in children hailing from low socioeconomic status, infants of vegetarian mother, and infants with delayed or improper weaning. Screening for Vitamin B12 deficiency is essential in all infants and children with unexplained neuroregression, as this disorder is potentially treatable. More population-based studies in India are needed to explore the prevalence of Vitamin B12 deficiency in pregnant and lactating women and also to assess the need for Vitamin B12 supplementation during pregnancy and lactation. [ABSTRACT FROM AUTHOR]

Background: Glutaric aciduria type I is an autosomal recessive organic acid disorder. The primary defect is the deficiency of Glutaryl-CoA dehydrogenase (EC number 1.3.99.7) enzyme that is involved in the catabolic pathways of the amino acids l-lysine, l-hydroxylysine, and l-tryptophan. It is a treatable neuro-metabolic disorder. Early diagnosis and treatment helps in preventing brain damage., Methods: The Glutaryl-CoA dehydrogenase gene (GCDH) gene was sequenced to identify disease causing mutations by direct sequencing of all the exons in twelve patients who were biochemically confirmed with GA I., Results: We identified eleven mutations of which nine are homozygous mutations, one heterozygous and two synonymous mutations. Among the eleven mutations, four mutations p.Q162R, p.P286S, p.W225X in two families and p.V410M are novel. A milder clinical presentation is observed in those families who are either heterozygous or with a benign synonymous SNP. Multiple sequence alignment (MSA) of GCDH with its homologues revealed that the observed novel mutations are not tolerated by protein structure and function., Conclusions: The present study indicates genetic heterogeneity in GCDH gene mutations among South Indian population. Genetic analysis is useful in prenatal diagnosis and prevention. Mutation analysis is a useful tool in the absence of non-availability of enzyme assay in GA I., (Copyright © 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)