Background: FanconiBickel syndrome (FBS) is a rare glycogen storage disease characterized by hepato-renal glycogen accumulation, severe renal tubular dysfunction and impaired glucose and galactose metabolism. We present the case histories of two sisters who were diagnosed with FBS.
Case reports: The proband, Lina, was referred to our clinic for growth retardation and abdominal distention aged 27 months. She is the 4th child of consanguineous parents and was born small-for-gestational age (BW 2700 g at 41 weeks gestation). She received oral vitamin D3 at 1 and 6 months according to our national rickets prevention program. At initial examination auxology showed: severe short stature height −5.72 SDS;BMI −0.98 SDS. There was hepatomegaly, gross motor delay but normal intelligence. She had clinical manifestations of severe rickets with odd-shaped skull, pigeon chest, swollen wrist and ankle joints and bowing of the legs. X-rays showed typical signs of rickets with multiple fractures. Laboratory investigations confirmed severe hypophosphatemic rickets with calcium 96 mg/l (90110 mg/l), phosphate 12 mg/l (4060 mg/l) and proximal renal tubular dysfunction with glycosuria. She also showed fasting hypoglycemia (glucose 0.4 g/l) and postprandial hyperglycemia (glucose 2.2 g/l). Molecular analysis of the SLC2A2 (GLUT2 gene) revealed a homozygous splicing mutation c.964-2A>C (intron 7). She was treated with oral phosphorus and 1-αVitamin D and the parents were encouraged to frequent meals with adequate caloric intake; and uncooked cornstarch. Amani, sister of the proband, was not small-for-gestational age (BW 3200 g at 38 weeks gestation). She was first evaluated at the age of 7 months when auxology showed: height: −2.43 SDS, weight: −2.24 SDS, BMI:-1.07 SDS. By this age she was already showing clinical and radiological signs of rickets. Laboratory investigations were consistent with the diagnosis of FBS.
Conclusion: The association of short stature, hypophosphatemic rickets and impaired glucose homeostasis is very evocative of FBS. Our proband presented with a homozygous SLC2A2 mutation which resulted in a severe phenotype.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology