IVD and metabolic acidosis: IVA, encoded by the IVD gene, is classified into two diverse phenotypes: the acute neonatal form causes metabolic acidosis, leading to lethargy, vomiting, coma, or death, while the chronic form typically has a late onset in childhood with an asymptomatic phenotype (Vockley and Ensenauer, 2006; Schlune et al., 2018; Ding et al., 2022).