Fanconi-Bickel syndrome in two Palestinian children: marked phenotypic variability with identical mutation.

BACKGROUND: Fanconi-Bickel syndrome (FBS, OMIM 227810) is a rare autosomal recessive disease caused by a deficiency of glucose transporter 2 (GLUT2), a member of the facilitative glucose transporter family (Santer et al. J Inherit Metab Dis 21:191-194, 1998). The typical clinical picture is characterized by hepatorenal glycogen accumulation resulting in hepato- and nephromegaly, impaired utilization of glucose and galactose, proximal renal tubular dysfunction, rickets and severe short stature. CASE PRESENTATION: We report 2 Palestinian patients from 2 families who were homozygous for the mutation p.R301X (C>T) in exon 7of GLUT2 gene. Patient 1 showed clinical and laboratory improvement with age characterized by normal growth and resolution of rickets. Patient 2 had severe phenotype characterized by progressive weight loss, persistent metabolic acidosis, marked polyuria and clinical and laboratory findings of rickets progressing to death at age 10 months. CONCLUSION: This report further expands the clinical spectrum of FBS even with identical mutations. Other yet unknown genetic, environmental or stochastic factors may be responsible for phenotypic variability.

A distinct phenotype of childhood leukodystrophy presenting as absence seizure.

Leukoencephalopathy refers to any disease of the white matter including hereditary as well as acquired and toxic causes. Inherited leukodystrophies are diseases of myelin including abnormal myelin development, hypomyelination, or degeneration of myelin. We report a 6-year old female who presented with absence seizure at the age of 4 years. Cerebral magnetic resonance imaging (MRI) of the brain showed bilateral periventricular confluent high signal intensity. The seizure responded to anticonvulsant therapy, and the clinical course was characterized by normal development and neurological examination.