Correspondence  Open Access
J Korean Med Sci. 2018 Feb 12;33(7):e71. English.
Published online Jan 22, 2018.  https://doi.org/10.3346/jkms.2018.33.e71
© 2018 The Korean Academy of Medical Sciences.
The Author's Response: Genetic Contributions to Childhood Obesity: Association of Candidate Gene Polymorphisms and Overweight/Obesity in Korean Preschool Children
Kee Hwan Yoo, Hyung Eun Yim, Eun Soo Bae and Young Sook Hong
Department of Pediatrics, Korea University Ansan Hospital, Ansan, Korea.

Address for Correspondence: Hyung Eun Yim, MD, PhD. Department of Pediatrics, Korea University Ansan Hospital, 123 Jeokgeum-ro, Danwon-gu, Ansan 15355, Republic of Korea. Email: he-yim@hanmail.net
Received January 12, 2018; Accepted January 12, 2018.

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


 See the letter "Letter to the Editor: Genetic Contributions to Childhood Obesity: Association of Candidate Gene Polymorphisms and Overweight/Obesity in Korean Preschool Children" in volume 33, number 7, e68.



Thank you for the comments on our publication.1 We agree with the author's perspective to a certain degree, but there are some issues that need to be clarified. As the authors mentioned, the gene symbol of angiotensin II type 2 receptor (OMIM: 300034) is not AT2 but AGTR2. We just used the common abbreviation ‘AT2’ for the angiotensin II type 2 receptor, not considering the gene representation. Additionally, it seems meaningful to analyze the genotypes in each gender group separately as suggested. Unfortunately, we could not further reanalyze the genotypes in each gender group due to the small sample size. However, we have already confirmed no differences among the groups with respect to gender among the three groups. We may not conclude the genetic variation in the AGTR2 gene is not related with the incidence of overweight, but the results should be interpreted with caution as mentioned earlier. Regarding the Hardy-Weinberg equilibrium test, differences between observed and expected frequencies of genotype variants are relatively common in clinical studies.2 In particular the test may be inappropriate in complex survey designs.3 Thank you again.

Notes

Disclosure:The authors have no potential conflicts of interest to disclose.

References
1.
Yoo KH, Yim HE, Bae ES, Hong YS. Genetic contributions to childhood obesity: association of candidate gene polymorphisms and overweight/obesity in Korean preschool children. J Korean Med Sci 2017;32(12):1997–2004.
2.
Piel FB, Adamkiewicz TV, Amendah D, Williams TN, Gupta S, Grosse SD. Observed and expected frequencies of structural hemoglobin variants in newborn screening surveys in Africa and the Middle East: deviations from Hardy-Weinberg equilibrium. Genet Med 2016;18(3):265–274.
3.
Moonesinghe R, Yesupriya A, Chang MH, Dowling NF, Khoury MJ, Scott AJ, et al. A Hardy-Weinberg equilibrium test for analyzing population genetic surveys with complex sample designs. Am J Epidemiol 2010;171(8):932–941.