Serum dopamine-beta-hydroxylase levels in Down's syndrome.

Abstract

Serum dopamine‐β‐hydroxylase (DBH) and serum immunoreactive (IR) DBH levels were measured in patients with Down's syndrome. Serum DBH activity was markedly reduced in Down's syndrome patients as compared with age matched, normal controls or non‐mongoloid, disturbed children. Serum IR‐DBH levels were also markedly reduced in Down's syndrome. The possible factors responsible for the observed reduction in serum DBH levels (active and inactive enzyme levels) in Down's syndrome were investigated.