Anti-glutamic acid decarboxylase antibody positivity

What it means

The presence of autoantibodies (immunoglobulins) in the serum that react against glutamic acid decarboxylase.

The enzyme called glutamate decarboxylase or glutamic acid decarboxylase (GAD) catalyyzes the conversion of glutamate to gamma aminobutyric acid (g-Amino butyric acid, GABA). Autoantibodies against GAD this antibody may block the conversion of glutamate to GABA. and lead to a reduction in the amount of GABA in the nervous system.

Rare diseases that can present with this3

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Anti-GAD antibody positivity