Massively parallel sequencing of genes associated with hypoglycaemia identified a previously reported (Emecen Sanli et al., 2022) homozygous likely pathogenic variant (c.705 + 5G>A) in FBP1, confirming a diagnosis of fructose-1,6-bisphosphatase deficiency. The gene discussed is FBP1; the disease is Hypoglycemia.