XXXX : onset in early infancy.

@entity1 @entity1831 @entity2011 @entity146 @entity5463 @entity368 @entity391 @entity4683 @entity74 @entity71100 @entity1521 @entity6659 @entity221 @entity3489
BACKGROUND: @entity6659 ( @entity6659 ), usually an @entity74 , is caused by mutations in the @entity5463 ( @entity1831 )-neurophysin II preprohormone leading to aberrant preprohormone processing and gradual destruction of @entity1831 -secreting cells. @entity1 typically present between 1 and 6 years of age with @entity2011 and @entity4683 . OBJECTIVE: Clinical, biochemical, and genetic studies of three new cases of @entity6659 presenting in early infancy. @entity1 : Three Palestinian cousins presented with failure to thrive, @entity391 , @entity146 , and @entity221 . The parents were asymptomatic. @entity1 developed @entity3489 (154-163 mmol/l) and serum hyperosmolality (>320 mOsm/kg), while urine osmolality remained between 73 and 229 mOsm/kg. Plasma @entity1831 levels were low, and the posterior pituitary bright spot was absent on magnetic resonance imaging (MRI). All @entity1 responded to desmopressin. RESULTS: @entity1 were homozygous and parents were heterozygous for microsatellite markers flanking the @entity1831 gene. All @entity1 were homozygous for the @entity71100 ( @entity1521 to @entity368 ) substitution affecting mature @entity1831 . A founder effect with the single original kindred carrying the @entity71100 mutation was confirmed by microsatellite analysis, but @entity1 in that family presented only at 2 years of age. In microsatellite analysis, the new kindred @entity1 were not homozygous and did not share a single allele at the aquaporin 2 and vasopressin receptor-2 genes locuses. CONCLUSION: This is the first description of @entity6659 presenting in the neonatal period. The unusual early clinical and radiological (MRI) presentation argues against gradual destruction of @entity1831 -secreting neurons as the pathophysiological mechanism. Factors beside allelism of @entity1831 -related genes must influence the age of @entity6659 presentation given the founder effect demonstrated for the @entity71100 mutation.
