Fanconi-Bickel Syndrome with Variable Phenotypes: A Case Series Highlighting a Successful Pregnancy Outcome from a Tertiary Care Center in North India

Fanconi-Bickel syndrome (FBS) is a rare autosomal recessive disorder caused by biallelic mutations in the SLC2A2 gene, characterized by proximal renal tubular dysfunction, hepatomegaly, and growth failure. We report five patients from three unrelated families in North India, including a sibling trio with significant intrafamilial variability and one of the few documented successful pregnancies in an affected female. Genetic testing identified a recurrent nonsense variant c.1093C>T (p.Arg365Ter) in two families and a missense variant c.1330T>C (p.Trp444Arg) in the third. The phenotypic spectrum ranged from mild growth delay to severe skeletal involvement and poor therapeutic response. Our report underscores the clinical variability of FBS, the importance of molecular diagnosis, and the need for long-term monitoring.