Achalasia, a poorly relaxing lower esophageal sphincter, produces a functional 
obstruction and the expected symptoms of dysphagia, regurgitation and eventually 
weight loss. The cause of achalasia remains largely unknown in Western 
countries, Chagas' disease being the most frequent etiology in Brazil. We report 
on two sets of monozygotic male twins with typical manifestations of achalasia. 
The majority of authors attribute a limited contribution unless achalasia is 
related to a multisystem disorder, like the triple-A or Allgrove's syndrome, an 
autosomal recessive disease characterized by the triad of adrenocorticotropic 
hormone (ACTH) resistant adrenal insufficiency, achalasia and alacrima. The four 
cases reported demonstrated the genetic influence of achalasia in patients 
without multisystem disorders. We believe that idiopathic achalasia is a 
syndrome with similar clinical, pathological, radiological and manometric 
evolution, but with a great variety of etiological agents, one of them being the 
congenital form.