A previous family-based linkage study revealed that Kawasaki disease (KD) was associated with variations of the ATP-binding cassette subfamily C member 4 (ABCC4) gene in most European populations. However, significant differences exist among ethnic populations in European and Chinese subjects; therefore, whether ABCC4 variants indicate susceptibility to KD in Chinese children is unclear. The purpose of this research was to evaluate correlations between ABCC4 gene polymorphisms and susceptibility to KD in a Southern Chinese population. We genotyped six polymorphisms (rs7986087, rs868853, rs3765534, rs1751034, rs3742106, and rs9561778) in 775 KD patients and 774 healthy controls. Ninety-five percent confidence intervals (95% CIs) and odds ratios (ORs) were used to assess the strength of each association. We found that the rs7986087 T variant genotype was associated with significantly higher susceptibility to KD (adjusted OR = 1.30, 95% CI = 1.05–1.60 for rs7986087 CT/TT). However, the rs868853 T variant genotype was associated with significantly lower susceptibility to KD (adjusted OR = 0.74, 95% CI = 0.59–0.92 for rs868853 CT/CC). Compared with the patients with 0–4 ABCC4 risk genotypes, the patients with 5-6 ABCC4 risk genotypes had a significantly increased risk of KD (adjusted OR = 1.63, 95% CI = 1.07–2.47), and this risk was more significant in the subgroups of females, subjects aged 12–60 months, and individuals with coronary artery lesions. These results indicate that specific single-nucleotide polymorphisms in the ABCC4 gene may increase susceptibility to KD in a Southern Chinese population.
Kawasaki disease (KD) manifests as acute systemic vasculitis in medium-sized arteries and primarily affects infants and children under five years of age [
A genome-wide association study (GWAS) is the primary method used to identify hereditary genetic variation related to multiple complex human diseases, such as KD [
A total of 775 patients with KD were enrolled in the study. They were diagnosed according to the criteria of the American Heart Association [
We selected SNPs of interest using the NCBI SNP (
The genotype frequencies at each locus and the demographic variables (e.g., gender and age) were compared between the healthy controls and the KD patients by using the
A total of 775 KD patients and 774 gender-, age-, and ethnicity-matched controls were included in the present study (Table
Frequency distribution of selected characteristics in Kawasaki disease patients and healthy controls.
Variables | Patients ( |
Controls ( |
|||
---|---|---|---|---|---|
No. | % | No. | % | ||
Age range, month | 1–166 | 1–144 | 0.2228 | ||
Mean ± SD | 29.11 ± 24.86 | 25.65 ± 23.30 | |||
<12 | 185 | 23.87 | 177 | 22.87 | |
12–60 | 527 | 68 | 550 | 71.06 | |
>60 | 63 | 8.13 | 47 | 6.07 | |
Gender | |||||
Male | 524 | 67.61 | 525 | 67.83 | 0.9274 |
Female | 251 | 32.39 | 249 | 32.17 | |
CAA | 103 | 13.29 | |||
CAL | 187 | 24.13 | |||
NCAL | 485 | 62.58 |
aTwo-sided
All observed genotype frequency distributions among the six SNPs were in accordance with HWE in the control subjects. Among the six investigated SNPs, significant differences were found in the genotype distributions for rs7986087 T (
Genotype frequency distribution of ABCC4 in KD patients and healthy controls.
Genotype | Patients ( |
Controls ( |
OR (95% CI) | Adjusted OR (95% CI) | |||
---|---|---|---|---|---|---|---|
CC | 488 (62.97) | 530 (68.48) | 1.000 | 1.000 | |||
CT | 257 (33.16) | 207 (26.74) | |||||
TT | 30 (3.87) | 37 (4.78) | 0.88 (0.54–1.45) | 0.6160 | 0.90 (0.55–0.48) | 0.6794 | |
Dominant | 287 (37.03) | 244 (31.52) | |||||
Recessive | 745 (96.13) | 737 (95.22) | 0.0786 | 0.80 (0.49–1.31) | 0.3815 | 0.82 (0.50–1.34) | 0.4193 |
AA | 171 (22.06) | 191 (24.68) | 0.1618 | 1.000 | 1.000 | ||
AC | 389 (50.19) | 399 (51.55) | 1.09 (0.85–1.40) | 0.5026 | 1.09 (0.85–1.40) | 0.4829 | |
CC | 215 (27.74) | 184 (23.77) | 1.30 (0.98–1.74) | 0.0672 | 1.32 (0.99–1.76) | 0.0547 | |
Dominant | 604 (77.93) | 583 (75.32) | 0.2243 | 1.16 (0.91–1.46) | 0.2250 | 1.17 (0.92–1.48) | 0.2032 |
Recessive | 560 (72.25) | 590 (76.23) | 0.0740 | 1.23 (0.98–1.55) | 0.0747 | 1.25 (0.99–1.57) | 0.0608 |
GG | 381 (49.16) | 410 (52.97) | 0.2779 | 1.000 | 1.000 | ||
GT | 332 (42.84) | 312 (40.31) | 1.14 (0.93–1.41) | 0.2023 | 1.14 (0.93–1.41) | 0.2147 | |
TT | 62 (8) | 52 (6.72) | 1.28 (0.86–1.90) | 0.2160 | 1.25 (0.84–1.86) | 0.2625 | |
Dominant | 394 (50.84) | 364 (47.03) | 0.1336 | 1.16 (0.95–1.42) | 0.1339 | 1.16 (0.95–1.41) | 0.1519 |
Recessive | 713 (92) | 722 (93.28) | 0.3338 | 1.21 (0.82–1.77) | 0.3358 | 1.18 (0.80–1.73) | 0.3950 |
CC | 36 (4.65) | 34 (4.39) | 0.8256 | 1.000 | 1.000 | ||
CT | 271 (34.97) | 282 (36.43) | 0.91 (0.55–1.49) | 0.7026 | 0.94 (0.57–1.56) | 0.8223 | |
TT | 468 (60.39) | 458 (59.17) | 0.96 (0.59–1.57) | 0.8860 | 1.01 (0.61–1.63) | 0.9932 | |
Dominant | 739 (95.36) | 740 (95.6) | 0.8110 | 0.94 (0.58–1.52) | 0.8111 | 0.98 (0.60–1.59) | 0.9346 |
Recessive | 307 (39.62) | 316 (40.82) | 0.6262 | 1.05 (0.86–1.29) | 0.6261 | 1.05 (0.86–1.29) | 0.6104 |
CC | 701 (90.45) | 677 (87.47) | 0.1689 | 1.000 | 1.000 | ||
CT | 73 (9.42) | 96 (12.4) | 0.73 (0.53–1.01) | 0.0604 | 0.74 (0.53–1.02) | 0.0666 | |
TT | 1 (.13) | 1 (.13) | 0.97 (0.06–15.47) | 0.9804 | 0.73 (0.04–12.14) | 0.8294 | |
Dominant | 74 (9.55) | 97 (12.53) | 0.0606 | 0.74 (0.53–1.01) | 0.0617 | 0.74 (0.54–1.02) | 0.0650 |
Recessive | 774 (99.87) | 773 (99.87) | 0.9993 | 1.00 (0.06–16.02) | 1.0000 | 0.75 (0.04–12.43) | 0.8421 |
CC | 18 (2.32) | 18 (2.33) | 1.000 | 1.000 | |||
CT | 228 (29.42) | 181 (23.39) | 1.26 (0.64–2.49) | 0.5070 | 1.28 (0.65–2.54) | 0.4749 | |
TT | 529 (68.26) | 575 (74.29) | 0.92 (0.47–1.79) | 0.8056 | 0.92 (0.48–1.80) | 0.8190 | |
Dominant | 757 (97.68) | 756 (97.68) | 0.9969 | 1.00 (0.52–1.94) | 0.9969 | 1.01 (0.52–1.96) | 0.9764 |
Recessive | 246 (31.74) | 199 (25.72) | |||||
0–4 | 691 (89.16) | 722 (93.28) | 1.000 | 1.000 | |||
5-6 | 84 (10.84) | 52 (6.72) | 0.0040 |
a
After adjusting for age and gender, when the rs7986087 CC genotype was used as the reference, the T variant genotypes were associated with an increased risk of KD (adjusted OR = 1.37, 95% CI = 1.09–1.70 for CT; adjusted OR = 0.90, 95% CI = 0.55–1.48 for TT; and adjusted OR = 1.30, 95% CI = 1.05–1.60 for CT/TT). When the rs868853 CC genotype was used as the reference, the T variant genotypes were associated with a decreased risk of KD (adjusted OR = 1.28, 95% CI = 0.56–2.54 for CT; adjusted OR = 0.92, 95% CI = 0.48–1.80 for TT; and adjusted OR = 0.74, 95% CI = 0.59–0.92 for CT/CC). However, the risk of KD was not associated with the other four SNPs. A combination analysis showed that the risk of KD was significantly higher in individuals with 5-6 risk genotypes than in individuals with 0–4 risk genotypes (adjusted OR = 1.63, 95% CI = 1.07–2.47,
We further determined the associations between variant genotypes of six selected SNPs in the ABCC4 gene and the risk of KD by stratifying the subjects by subgroups, including age, sex, and coronary artery outcomes (Table
Stratification analysis of susceptibility in Kawasaki disease patients.
Variables | Combined effect of risk genotypes (patients/controls) | OR (95% CI) | Adjusted OR (95% CI) | ||||
---|---|---|---|---|---|---|---|
0–4 | 5-6 | ||||||
<12 | 163/162 | 22/15 | 0.2818 | 1.46 (0.73–2.91) | 0.2854 | 1.46 (0.73–2.91) | 0.2855 |
12–60 | 475/516 | 52/34 | 0.0253 | ||||
>60 | 53/44 | 10/3 | 0.1155 | 2.77 (0.72–10.68) | 0.1397 | 3.52 (0.87–14.33) | 0.0790 |
Male | 477/488 | 47/37 | 0.2510 | 1.30 (0.83–2.04) | 0.2526 | 1.31 (0.84–2.06) | 0.2378 |
Female | 214/234 | 37/15 | 0.0012 | ||||
CAA | 91/722 | 12/52 | 0.0904 | 1.83 (0.94–3.56) | 0.0744 | 1.84 (0.94–3.60) | 0.0748 |
CAL | 170/722 | 17/52 | 0.2727 | 1.39 (0.78–2.46) | 0.2609 | 1.39 (0.78–2.47) | 0.2619 |
NCAL | 430/722 | 55/52 | 0.0047 |
a
In the present case-control study, which included 775 KD patients and 774 healthy controls, we show that the ABCC4 gene rs7986087 T variant genotype was correlated with increased susceptibility to KD. However, the rs868853 T variant genotype was associated with decreased susceptibility to KD. To the best of our knowledge, this is the first study to investigate the association between ABCC4 gene polymorphisms and susceptibility to KD in Southern Chinese children.
ABCC4, also known as MRP4, is a large gene (282 kb) [
GWAS is an efficient method to identify inherited genetic variations that are associated with complex human diseases [
Khor et al. observed that the rs7986087 T variant genotype significantly increased KD susceptibility in a European population. Notably, in our study, we observed similar results in Southern Chinese children. In contrast, we found that rs868853 T variant genotypes decreased KD susceptibility in Southern Chinese children, unlike the research of Khor et al., in which no associations with KD susceptibility were found. These findings suggest that rs868853 T variant genotypes may be more race-specific at the genetic level. However, it is not clear why ABCC4 rs868853 variants play opposite effects on susceptibility to KD. This is also a limitation of our research.
When the six ABCC4 SNPs were analyzed, we found that patients with 5 or more KD risk genotypes were significantly more likely to develop the disease than were those with only 0–4 of the risk genotypes. The population with the highest incidence of KD was previously reported to be children between 6 months and 5 years of age in many countries around the world [
Although this is the first study to investigate ABCC4 genetic polymorphisms in Southern Chinese children with Kawasaki disease, the limitations of this study should be understood. First, the current sample size was not large enough. Multicenter studies with larger sample sizes are required to validate the relationship between ABCC4 gene polymorphisms and susceptibility to KD. Second, we evaluated only six ABCC4 SNPs that were identified in a previous genome-wide linkage study. No other potentially functional SNPs were investigated. Additional potentially functional ABCC4 gene polymorphisms should be investigated. Finally, this study was retrospective; only gender and age were adjusted in the logistic regression analysis. In addition, we were unable to collect or control for other factors, such as dietary intake or environment exposure in the parents and children.
In summary, the results of the present study confirm that in a Southern Chinese population, the ABCC4 gene polymorphism rs7986087 T variant genotype is associated with significantly higher susceptibility to KD, whereas the rs868853 T variant genotype was associated with significantly lower susceptibility to KD. Increasing our knowledge of this gene’s function in KD may provide valuable insights into its role in the disease pathogenesis. However, multicenter studies that involve practical experiments and have larger sample sizes should be performed to further characterize ABCC4 and determine the mechanisms underlying its role in KD.
Non-coronary artery lesions
Coronary artery lesions
Coronary artery aneurysm
ATP-binding cassette subfamily C member 4
Genome-wide association study.
The data used to support the findings of this study are included within the article.
This study was performed with the approval of the Institutional Committee of Guangzhou Women and Children’s Medical Center (2015090113).
All participants gave written informed consent.
The authors report no conflicts of interest.
Di Che, Lei Pi, and Zhenzhen Fang contributed equally to this study.
We thank the Clinical Biological Resource Bank of Guangzhou Women and Children’s Medical Center for providing all of the clinical samples used in this study. We thank Professor He for his guidance during the data analysis. This study was supported by the Guangdong Natural Science Fund of China (grant number 2016A030313836), the Guangdong Provincial Science and Technology Projects of China (grant numbers 2014A020212012, 2014A020212613, and 2014A020212023), the Guangzhou Science and Technology Plan Project of China (grant numbers 201510010159, 201510010287, 201607010011, and 201804010035), the Guangzhou Medical and Health Technology Projects of China (grant numbers 20161A010030 and 20171A011260), and the National Key Basic Research and Development Program (973 Program) of China (grant number 2015CB755402).