PLCXD3 and major depressive disorder: However, the haplotype analysis of this region suggested that the associated peak might be located more likely downstream to OXCT1 and upstream to PLCXD3. This result is consistent with the 90 Kbp-deletion reported in one of the French patients and that removed the promoter region and the first coding exon of PLCXD3. Further exploration of this gene revealed a mutation predicting to change the amino acid sequence of the protein (p.R93H) and transmitted from his father, who had a first cousin with major depressive disorder.