“…In total, 17 population-based studies 9,14,33,34,38,46,50,51,56,60,61,66,[68][69][70] and six family-based studies 12,32,42,53,63,74 were about 5-HTTLPR. A total of 16 population-based studies 27,33,35,38,41,47,[49][50][51]54,56,58,60,61,70,75 and four family-based studies 12,52,57,63 were about the intron 2 VNTR. Among the population-based studies, some used matched controls according to the ethnicity 41,47,50,60,66,69 and others explicitly verified the ethnic homogeneity of the sample through the ancestry history.…”