<aside> 📘 Achalasia, A Systematic Review, JAMA, 2015

</aside>

Epidemiology and Genetics of Achalasia

Epidemiology

• Annual reported incidence: Approximately 1/100,000 worldwide

Genetic factors

• Associated with conditions like Parkinson's disease, Allgrove syndrome, and Down syndrome
• Familial achalasia is reported, including one family with autosomal dominant pattern
• Polymorphisms in nitric oxide synthase gene and interleukins (IL-23 and IL-10) have been investigated.

Pathophysiology

Pathophysiology

• Associated with functional loss of myenteric plexus ganglion cells in the distal esophagus and lower esophageal sphincter
• Consequences
  • Dysfunction of inhibitory postganglionic neurons in these areas
  • Impaired relaxation of the lower esophageal sphincter
  • Potential hypercontractility of the distal esophagus
  • Rapidly propagated contractions in the distal esophagus
  • Persistent longitudinal muscle contractions and esophageal shortening
• Potential causes
  • Exact cause is unknown
  • May be an autoimmune process triggered by an indolent viral infection (herpes, measles) in genetically susceptible individuals
  • Higher prevalence of concomitant autoimmune diseases and serum neural autoantibodies in achalasia patients
  • Can be a manifestation of Chagas disease, caused by Trypanosoma cruzi parasite

Symptoms and Signs

• Achalasia is characterized by progressive dysphagia to both solids and liquids, which is the hallmark symptom of the condition.
• Younger patients exhibit higher rates of heartburn and chest pain compared to older patients.
• Obese patients (BMI ≥ 30) may experience more frequent symptoms of choking and vomiting.
• Women report chest pain more commonly than men, though some studies show no significant difference in chest pain reports based on age or sex.