Allgrove syndrome with features of familial dysautonomia: a novel mutation in the AAAS gene

Allgrove syndrome (or triple-A syndrome) is a rare autosomal recessive disorder characterized by alacrima, achalasia, adrenal insufficiency (glucocorticoid in the majority of cases) and autonomic/neurological abnormalities. This disease is now known to be caused by mutation in the AAAS gene located on chromosome 12q13. Diagnosis should be readily available when the full-blown features are there, but it becomes less apparent when presentation is atypical or in the evolving process. We present a brother and sister (12 and 19 y old, respectively) born to consanguineous parents of Palestinian origin with Allgrove syndrome. The index patient was erroneously diagnosed to be a case of familial dysautonomia before the diagnosis of adrenal insufficiency was made at the age of 7.5 y, while his elder sister had only alacrima from birth and developed achalasia at the age of 15 y. She started to develop early evidence of adrenal disease at the age of 19 y. Both of them had neuroautonomic dysfunction. The diagnosis of Allgrove syndrome was confirmed in these two patients by studying the gene mutation in the family. The sequencing of the AAAS gene in the two patients identified a novel homozygous mutation within intron 5 (IVS5+1G-->A). Both parents as well as all three other children were heterozygous for the same mutation. CONCLUSION: These two cases illustrate the heterogenous nature and the intrafamilial phenotypic variability of Allgrove syndrome.