To the Editor:

We thank Sookaromdee and Wiwanitkit for their interest and comments on our manuscript. The authors have highlighted the importance of further studies to evaluate the effects of other polymorphisms on primary open-angle glaucoma (POAG). As published by Weinreb et al.⁽¹⁾, glaucoma is a multifactorial disease with incompletely understood pathophysiology. Bailey et al.⁽²⁾ published a genome-wide association study (GWAS) describing 22 POAG-related single nucleotide polymorphisms (SNPs), of which 19 had been previously described. In addition, Bonnemaijer⁽³⁾ confirmed the relationship of 15 SNPs with glaucoma in the African population.

Although GWAS studies are important to identify new common polymorphisms associated with diseases, this strategy has some limitations⁽⁴⁾ that may lead to false-positive results. In addition, most studies were performed in European and North American populations; therefore, it is of fundamental importance to confirm these polymorphisms in other populations, such as the Brazilian, which has a highly admixed population. Therefore, we decided to verify the association of TXNRD2 (rs35934224) with POAG in a Brazilian population.

As exposed in our work, we also have the conviction that further studies are needed to confirm these associations and try to better understand the disease pathophysiology to be able to propose curative therapies based on these data.

REFERENCES

1. Weinreb RN, Leung CKS, Crowston JG, Medeiros FA, Friedman DS, Wiggs JL, et al. Primary open-angle glaucoma. Nat Rev Dis Primers. 2016;2:16067. doi:10.1038/nrdp.2016.67

2. Bailey JN, Loomis SJ, Kang JH, Allingham RR, Gharahkhani P, Khor CC, et al. Genome-wide association analysis identifies TXNRD2, ATXN2 and FOXC1 as susceptibility loci for primary open-angle glaucoma. Nat Genet [Internet]. 2016[cited 2020 Oct 15];48(2):189-94. Available from: Genome-wide association analysis identifies TXNRD2, ATXN2 and FOXC1 as susceptibility loci for primary open angle glaucoma (nih.gov)

3. Bonnemaijer PWM, Iglesias AI, Nadkarni GN, Sanyiwa AJ, Hassan HG, Cook C; GIGA Study Group, Simcoe M, Taylor KD, Schurmann C, Belbin GM, Kenny EE, Bottinger EP, van de Laar S, Wiliams SEI, Akafo SK, Ashaye AO, Zangwill LM, Girkin CA, Ng MCY, Rotter JI, Weinreb RN, Li Z, Allingham RR; Eyes of Africa Genetics Consortium, Nag A, Hysi PG, Meester-Smoor MA, Wiggs JL; NEIGHBORHOOD Consortium, Hauser MA, Hammond CJ, Lemij HG, Loos RJF, van Duijn CM, Thiadens AAHJ, Klaver CCW. Genome-wide association study of primary open-angle glaucoma in continental and admixed African populations. Hum Genet [Internet]. 2018 [cited 2019 Mar 19];137(10):847-62. Available from: Genome-wide association study of primary open-angle glaucoma in continental and admixed African populations (nih.gov)