A novel SLC25A13 gene splice site variant causes Citrin deficiency in an infant

•The variant c.848 + 6 T > C in the SLC25A13 gene is a novel splice site variant.•We proved the variant resulted in an aberrant RNA product.•It manifested clinically as neonatal citrin deficiency (NICCD, OMIM #605814).•Prognosis is fair with early diagnosis and supportive treatment. Citrin deficiency is an autosomal recessive disorder associated with SLC25A13 gene pathogenic variants, with more than a hundred known at present. It manifests in neonates as failure to thrive and acute liver insufficiency. We herein describe a case of a 4-week-old infant who presented with insufficient weight gain and liver failure accompanied by hyperammonemia. She was diagnosed with Citrin deficiency after a thorough biochemical and molecular analysis including amino acid profile, DNA sequencing of genes of interest and RNA splice site evaluation, to reveal a yet unknown damaging variant of the SLC25A13 gene.