[Fructose 1,6-bisphosphatase deficiency as a cause of recessive serious hypoglycaemia].

Fructose 1,6-bisphosphatase (FBPase) deficiency is an autosomal recessive disorder of gluconeogenesis. Here we describe a family from Morocco with parental consanguinity with three affected children. All were homozygous for a novel mutation in exon 5: 685 C-->T of the gene coding for the liver isoform of fructose 1,6-bisphosphatase (FBP1). The mutation changed the amino acid codon (Q229X) from a glutamine (CAG) in position 229 to a stop codon (TAG), which caused a shortening of the protein from the normal 338 amino acids to 228. The shortened protein lacks a major part of the active site and is therefore probably without enzymatic activity.