Ethnic Differences in Brain-derived Neurotrophic Factor Val66Met Polymorphism in Croatian and Korean Healthy Participants

Abstract

The study found significant ethnic differences in BDNF val66met polymorphism. The most frequent genotype among Korean participants was "Met/Val" and they had similar distribution of "Met" and "Val" alleles. In contrast, the most frequent genotype among Caucasian participants was "Val/Val" and they had different distribution of "Met" and "Val" alleles. These ethnic differences require matching participants for ethnicity in pharmacogenetic studies and in the studies investigating genetic variations in neuropsychiatric disorders.

No gene-by-environment interaction of BDNF Val66Met polymorphism and childhood maltreatment on anxiety sensitivity in a mixed race adolescent sample

“…The following genotype frequencies were evident in our mixed race sample: Val66Val (75.65%, 233/308), Val66Met (22.08%, 68/308) and Met66Met (2.3%, 7/308). These frequencies are generally in line with those determined in Caucasian samples (Carver et al, 2011; Gatt et al, 2009; Pivac et al, 2009; Surtees et al, 2007; Zeni et al, 2013) and in South African mixed race samples (Dalvie et al, 2014), and confirm the low rates of Met66 allele carriers evident in ethnic groups in sub-Saharan Africa (Petryshen et al, 2009). Given the low frequency of Met66Met genotype carriers, Val66Met and Met66Met genotypes were combined (24.35%, 75/308) for genotypic analyses to increase statistical power.…”

“…Firstly, the grouping of Met66 allele carriers (i.e. Met66Met and Val66Met genotypes), as is frequently carried out in studies in which the rate of the Met66Met genotype is relatively low, such as in Caucasian samples (Gatt et al, 2009; Lehto, Maestu, Kiive, Veidebaum, & Harro, 2016; Nedic et al, 2013; Pivac et al, 2009), may introduce a bias in which a main effect of genotype is not detected due to the exclusion of the Met66Met genotype in analyses (Notaras et al, 2015). Secondly, the Val66Met and Met66Met genotypes, respectively, may have dissimilar effects (Hong et al, 2012).…”

Association between brain-derived neurotrophic factor Val66Met and obesity in children and adolescents

“…To evaluate whether the children and adolescents in the present study have a similar distribution of the gene variants of the BDNF Val66Met polymorphism with other healthy groups of the same ethnic origin, we compared the distribution of BDNF variants between the young participants of the present study (10.8 ± 4.1 years old) with the distribution in 556 healthy adult subjects (33.8 ± 9.1 years old) and 402 healthy aging subjects (75.7 ± 7.4 years old) included in our previous studies (Pivac et al, 2009;Pivac et al, 2011). No significant differences were found in the frequency of the genotypes (χ 2 = 1.506; d.f.…”

“…Hardy-Weinberg equilibrium (Saleh et al, 2006) and Standardized residuals (R) to determine which genotype was the major influence on the significant chi-square test statistic (http://www.acastat.com/Statbook/chisqresid.htm) were evaluated using Microsoft Excel. Since the frequency of the homozygous Met/Met genotype is 3-4% in the Croatian population (Pivac et al, 2009;Pivac et al, 2011), to gain more statistical power, the combined Met/Val and Met/Met genotypes were grouped into Met carriers and compared with the homozygous Val/Val genotype. The study had adequate power (≥0.800) and sufficiently large sample size (n=248 required for this power; and the study included n=300) to detect a significant association.…”

“…Most of the studies evaluated the role of BDNF Val66Met in eating disorders, and found either a significant association (Akkermann et al, 2011;Gratacos et al, 2007), or no association (Arija et al, 2010;Friedel et al, 2005) between the Met allele and eating disorders. The ethnic (Pivac et al, 2009), as well as population-related genetic differences (Petryshen et al, 2010) might explain the conflicting association results showing either that BDNF Val66Met Met/Met genotype was more frequently found in adult women with higher (Beckers et al, 2008) or with lower (Shugart et al, 2009) BMI. Therefore, the aim of this study was to determine the association between BDNF Val66Met variants and obesity in healthy Caucasian children and adolescents of the same ethnic background of Croatian origin, subdivided according to the BMI measures.…”