Further evidence supporting the role of GTDC1in glycine metabolism and neurodevelopmental disorders

Bibliographic Details
Title: Further evidence supporting the role of GTDC1in glycine metabolism and neurodevelopmental disorders
Authors: Errichiello, Edoardo, Lecca, Mauro, Vantaggiato, Chiara, Motta, Zoraide, Zanotta, Nicoletta, Zucca, Claudio, Bertuzzo, Sara, Piubelli, Luciano, Pollegioni, Loredano, Bonaglia, Maria Clara
Source: European Journal of Human Genetics: EJHG; August 2024, Vol. 32 Issue: 8 p920-927, 8p
Abstract: Copy number variants (CNVs) represent the genetic cause of about 15–20% of neurodevelopmental disorders (NDDs). We identified a ~67 kb de novo intragenic deletion on chromosome 2q22.3 in a female individual showing a developmental encephalopathy characterised by epilepsy, severe intellectual disability, speech delay, microcephaly, and thin corpus callosum with facial dysmorphisms. The microdeletion involved exons 5-6 of GTDC1, encoding a putative glycosyltransferase, whose expression is particularly enriched in the nervous system. In a previous study, a balanced de novo translocation encompassing GTDC1was reported in a male child with global developmental delay and delayed speech and language development. Based on these premises, we explored the transcriptomic profile of our proband to evaluate the functional consequences of the novel GTDC1de novo intragenic deletion in relation to the observed neurodevelopmental phenotype. RNA-seq on the proband’s lymphoblastoid cell line (LCL) showed expression changes of glycine/serine and cytokine/chemokine signalling pathways, which are related to neurodevelopment and epileptogenesis. Subsequent analysis by ELISA (enzyme-linked immunosorbent assay) and HPLC (high-performance liquid chromatography) revealed increased levels of glycine in the proband’s LCL and serum compared to matched controls. Given that an increased level of glycine has been observed in the plasma samples of individuals with Rett syndrome, a condition sharing epilepsy, microcephaly, and intellectual disability with our proband, we proposed that the GTDC1downregulation is implicated in neurodevelopmental impairment by altering glycine metabolism. Furthermore, our findings expanded the phenotypic spectrum of the novel GTDC1-related condition, including microcephaly and epilepsy among relevant clinical features.
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ISSN:10184813
14765438
DOI:10.1038/s41431-024-01603-0
Published in:European Journal of Human Genetics: EJHG
Language:English