Clinical and molecular characteristics of fructose 1, 6 bisphosphatase deficiency in 6 Egyptian patients and two common variants.

backgroundFructose 1, 6 bisphosphatase (FBPase) deficiency is a rare autosomal recessive disease caused by mutations in the FBP1 gene. Symptoms of this disease are heterogeneous, with a variable age of onset, and are often confused with those of other inborn errors of metabolism. Biochemical testing is not conclusive, and patients usually need molecular testing for proper diagnosis and management. AIM OF STUDY: To describe clinical and molecular characteristics of patients with FBPase deficiency. PATIENTS AND

methodsThe study included six female patients diagnosed with FBPase deficiency, all recruited from the outpatient genetics clinic and the Children's Hospital at Ain Shams University, Faculty of Medicine. The mean age at presentation was 22.8 ± 16.16 months, while the mean age at diagnosis was 62 ± 45.16 months, indicating an average diagnostic delay of three years. The most common presenting symptoms were vomiting, fever, and lethargy. Hepatomegaly was the most frequently observed clinical sign on examination. Initial laboratory investigations commonly revealed ketotic hypoglycemia and metabolic acidosis. Molecular testing confirmed the diagnosis in all cases. Encouragingly, with appropriate management, all patients achieved normal neurocognitive outcomes.

conclusionFructose 1,6-bisphosphatase deficiency should be considered in children presenting with hypoglycemia and metabolic acidosis. Early molecular diagnosis is recommended to confirm the condition and to facilitate carrier screening and preventive strategies for at-risk family members.