SLC6A4 and major depressive disorder: In a study investigating the association of the 5HTTLPR polymorphism and the CpG (5mC) DNA methylation levels of the AluJb repeat element in the SLC6A4 promoter region (5HTTLPR) of a mother–child exposed to maternal depression, no correlation was found between the S allele and the pattern of depression occurrence between mother and child (p < 0.999), even though this association was seen in other studies [19,33,74].