Leukotriene C4 Synthase Deficiency Watchlist (log in to enable) Retrieved 2021-01-18 Source Wikipedia Trials — Genes LTC4S Drugs — Interested in hearing about new therapies? Registered! Leukotriene C4 synthase deficiency is an inborn error of metabolism. Deficiency of Leukotriene C4 synthase can lead to a reduction in Leukotriene C4.