aetiology

Last reviewed 12/2020

This condition usually develops in the first three to six weeks of life. It appears to be inherited in a multifactorial manner and is commonest in first-born, male children. There are associations with Turner's syndrome, oesophageal atresia and phenylketonuria.

Failure of the pyloric sphincter to relax may produce an intense work hypertrophy of the adjacent pyloric muscle.

Pyloric stenosis has been correlated with a deficiency in nitric oxide synthase in the myenteric plexus. It is thought that nitric oxide is essential for relaxation of the muscle (1).

Reference:

• Vanderwinden, J.M. et al (1992). Nitric oxide synthase activity in infantile hypertrophic pyloric stenosis. NEJM, 327(8), 511-5