The Number of Cysteine Residues per Mole in Apolipoprotein E Is Associated With the Severity of PTSD Re-Experiencing Symptoms.

Apolipoprotien E (ApoE) is involved in critical neural functions and is associated with various neuropsychiatric disorders. ApoE exists in three isoforms that differ in the number of cysteine residues per mole (CysR/mole). This study evaluated associations between this informative ordinal biochemical scale (CysR/mole) and symptom severity in veterans with posttraumatic stress disorder (PTSD) or subthreshold PTSD. Results demonstrated a significant negative relationship between the CysR/mole and severity of PTSD re-experiencing symptoms, adjusted for trauma. The findings suggest a genetic influence on PTSD symptomatology and dovetail with recent advances regarding the molecular mechanisms underlying the differential effects of ApoE in the brain.