Polymorphisms in <i>NAT2</i> (N-acetyltransferase 2) gene in patients with systemic lupus erythematosus

Santos, Elaine Cristina Lima dos; Pinto, Amanda Chaves; Klumb, Evandro Mendes; Macedo, Jacyara Maria Brito

doi:10.1016/j.rbre.2016.09.015

Elaine Cristina Lima dos Santos

Universidade do Estado do Rio de Janeiro (UERJ), Departamento de Bioquímica, Rio de Janeiro, RJ, Brazil

Amanda Chaves Pinto

Universidade do Estado do Rio de Janeiro (UERJ), Departamento de Bioquímica, Rio de Janeiro, RJ, Brazil

Evandro Mendes Klumb

Universidade do Estado do Rio de Janeiro (UERJ), Disciplina de Reumatologia, Rio de Janeiro, RJ, Brazil

Jacyara Maria Brito Macedo ^**Corresponding author. E-mails: jacyara@uerj.br, jacyarauerj@gmail.com (J.M. Macedo).

Universidade do Estado do Rio de Janeiro (UERJ), Departamento de Bioquímica, Rio de Janeiro, RJ, Brazil

*Corresponding author. E-mails: jacyara@uerj.br, jacyarauerj@gmail.com (J.M. Macedo).

Conflicts of interest

The authors declare no conflicts of interest.

Figures (1)
Tables (5)

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Fig. 1
Molecular analysis of four substitutions in the NAT2 gene. (A) Photograph of a 2.0% agarose gel stained with ethidium bromide for analysis of the substitution 481C>T. Lane 1 - negative control of the digestion reaction (intact amplicon); Lane 2 - representative sample of the NAT2 genotype 481CC (two alleles with KpnI restriction site); Lane 3 - representative sample of the NAT2 genotype 481CT (only one of the alleles with KpnI restriction site); Lane 4 - representative sample of the NAT2 genotype 481TT (two alleles without KpnI restriction site); Lane 5 - molecular weight pattern (GeneRulerTM 100 bp DNA Ladder, ready to use - Fermentas). (B) Photograph of a 6.0% polyacrylamide gel stained with ethidium bromide for analysis of the 590G>A substitution. Lane 1 - negative reaction control (intact amplicon); Lane 2 - representative sample of the NAT2 genotype 590GG (two alleles with an additional TaqI restriction site); Lane 3 - representative sample of the NAT2 genotype 590GA (only one of the alleles with an additional TaqI restriction site); Lane 4 - representative sample of the NAT2 genotype 590AA (two alleles without an additional TaqI restriction site); Lane 5 - molecular weight pattern (GeneRulerTM 100 bp DNA Ladder, ready to use - Fermentas). (C) Photograph of a 1% agarose gel stained with ethidium bromide for analysis of the 857G>A substitution. Lane 1 - negative control of digestion reaction (intact amplicon); Lanes 2 and 5 - representative samples of the NAT2 genotype 857GG (two alleles with an additional BamHI restriction site); Lanes 3 and 4 - representative samples of the NAT2 genotype 857GA (only one allele with an additional BamHI restriction site); Lane 6 - molecular weight pattern (GeneRulerTM 100 bp DNA ladder, ready to use - Fermentas). (D) Photograph of a 5% polyacrylamide gel stained with ethidium bromide for analysis of the 191G>A substitution. Lane 1 - representative sample of the NAT2 genotype 191GA (only one of the alleles with a Mspl restriction site); Lanes 2 and 3 - representative samples of the NAT2 genotype 191GG (two alleles of an additional MspI restriction site); Lane 4 - negative control for digestion reaction (intact amplicon); Lane 5 - molecular weight pattern (GeneRulerTM 1 kp DNA Ladder, ready to use - Fermentas).

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Table 1
Clinical characteristics of patients with systemic lupus erythematosus included in this study.

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Table 2
Genotype and allele distributions for each of the four substitutions of the NAT2 gene and acetylator phenotype in case- (patients with SLE) and control groups.

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Table 3
Distributions of haplotypes of the NAT2 gene in groups of cases (lupus SLE patients) and controls.

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Table 4
Analysis of interaction between genotypes related to substitutions in the NAT2 gene or NAT2 phenotype and ethnic origin, in case- (SLE patients) and control groups.

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Table 5
Frequencies of less frequent alleles of NAT2 (481T, 590A, 857A, 191A) observed in various populations.

Substitution/acetylator phenotype	Genotype/allele/phenotype	Cases (n = 91)	Controls^a a Hardy–Weinberg equilibrium test: NAT2 481C>T (p = 1.00); NAT2 590G>A (p = 0.50); NAT2 857G>A (p = 1.00); NAT2 191G>A (p = 0.19) (SNPStats). (n = 97)	Cases vs. controls
		n (%) or (f)	n (%) or (f)	OR (95% CI)
NAT2 481C>T	CC	40 (44)	34 (35)	1.00
	CT	39 (43)	46 (48)	0.72 (0.39–1.35)
	TT	12 (13)	16 (17)	0.64 (0.27–1.53)
	CT+TT	51 (56)	62 (65)	0.70 (0.39–1.26)
	C	119 (0.65)	114 (0.59)	1.00
	T	63 (0.35)	78 (0.41)	0.77 (0.51–1.18)

NAT2 590G>A	GG	53 (59)	66 (68)	1.00
	GA	32 (36)	27 (28)	1.48 (0.79–2.76)
	AA	5 (6)	4 (4)	1.56 (0.40–6.09)
	GA+AA	37 (41)	31 (32)	1.49 (0.82–2.71)
	G	138 (0.77)	159 (0.82)	1.00
	A	42 (0.23)	35 (0.18)	1.38 (0.84–2.29)

NAT2 857G>A	GG	70 (84)	88 (93)	1.00
	GA	13 (16)	7 (7)	2.34 (0.88–6.17)
	AA	0	0	N/A
	GA+AA	13 (16)	7 (7)	2.34 (0.88–6.17)
	G	153 (0.92)	183 (0.96)	1.00
	A	13 (0.08)	7 (0.04)	2.22 (0.86–5.71)

NAT2 191G>A	GG	87 (96)	81 (91)	1.00
	GA	4 (4)	7 (8)	0.53 (0.15–1.89)
	AA	0	1 (1)	N/A
	GA+AA	4 (4)	8 (9)	0.47 (0.14–1.61)
	G	178 (0.98)	169 (0.95)	1.00
	A	4 (0.02)	9 (0.05)	0.42 (0.13–1.40)

Phenotype	Fast	45 (53)	48 (53)	1.00
Phenotype	Slow	40 (47)	43 (47)	1.00 (0.56–1.82)

Haplotype of NAT2				Cases (f)	Controls (f)	Cases vs. controls
481C>T	590G>A	857G>A	191G>A			OR (95% CI)
T	G	G	G	0.3231	0.3990	1.00
C	G	G	G	0.3595	0.3405	1.25 (0.76–2.06)
C	A	G	G	0.2170	0.1653	1.67 (0.94–2.95)
C	G	A	G	0.0476	0.0360	1.89 (0.61–5.88)
C	G	G	A	0.0139	0.0435	0.63 (0.18–2.12)
T	G	A	G	0.0231	0	N/A

Substitution/acetylator phenotype	Skin color/ethnicity	Genotype/phenotype	Cases n (%)	Controls n (%)	Cases vs. controls OR (95% CI)
NAT2 481C>T	White	C/C	12 (36)	6 (27)	1.00
		C/T	19 (58)	11 (50)	0.86 (0.25–2.95)
		T/T	2 (6)	5 (23)	0.20 (0.03–1.35)
	Nonwhite	C/C	28 (48)	28 (38)	1.00
		C/T	20 (35)	35 (47)	0.57 (0.27–1.22)
		T/T	10 (17)	11 (15)	0.91 (0.33–2.48)

NAT2 590G>A	White	G/G	18 (55)	17 (77)	1.00
		G/A	14 (42)	4 (18)	3.31 (0.91–12.06)
		A/A	1 (3)	1 (5)	0.94 (0.05–16.34)
	Nonwhite	G/G	35 (61)	49 (65)	1.00
		G/A	18 (32)	23 (31)	1.10 (0.52–2.33)
		A/A	4 (7)	3 (4)	1.87 (0.39–8.87)

NAT2 857G>A	White	G/G	27 (90)	19 (86)	1.00
		G/A	3 (10)	3 (14)	0.70 (0.13–3.87)
		A/A	0	0	N/A
	Nonwhite	G/G	43 (81)	69 (95)	1.00
		G/A	10 (19)	4 (5)	4.01 (1.18–13.59) ^a a Fisher's test: p = 0.0230.
		A/A	0	0	N/A

NAT2 191G>A	White	G/G	32 (97)	20 (95)	1.00
		G/A	1 (3)	1 (5)	0.62 (0.04–10.57)
		A/A	0	0	NA
	Nonwhite	G/G	55 (95)	61 (90)	1.00
		G/A	3 (5)	6 (9)	0.55 (0.13–2.32)
		A/A	0	1 (1)	N/A

Phenotype	White	Fast	17 (55)	11 (52)	1.00
	White	Slow	14 (45)	11 (48)	1.21 (0.41–3.63)
	Nonwhite	Fast	28 (52)	37 (54)	1.00
	Nonwhite	Slow	26 (48)	32 (46)	0. 93 (0.46–1.90)

Populations	Substitutions of NAT2
	857G>A	481C>T	590G>A	191G>A
Africa^a a Sabbagh et al., 2011. Control data specific for each of disease models included in the case group.	0.04	0.30	0.25	0.09
Europe^a a Sabbagh et al., 2011. Control data specific for each of disease models included in the case group.	0.03	0.44	0.27	0.01
Asia^a a Sabbagh et al., 2011. Control data specific for each of disease models included in the case group.	0.12	0.18	0.27	0
America^a a Sabbagh et al., 2011. Control data specific for each of disease models included in the case group.	0.20	0.25	0.11	0.02
Oceania^a a Sabbagh et al., 2011. Control data specific for each of disease models included in the case group.	0.04	0.04	0.32	0
This study^b b Patients from control group.	0.08	0.35	0.23	0.02

[1] *Corresponding author. E-mails: jacyara@uerj.br, jacyarauerj@gmail.com (J.M. Macedo).

Clinical data
Age at onset of symptoms (mean ± SD) (years)	27.8 ± 10.9
Elapsed time between onset of symptoms and diagnosis of SLE (mean ± SD) (months)	20.0 ± 28.3

American College of Rheumatology (ACR) criteria (%)
Malar rash	78.0
Discoid lesions	15.4
Photosensitivity	72.5
Oral ulcers	53.8
Arthritis	84.6
Pleuritis	33.0
Pericarditis	28.6
Hematological abnormalities^a a Reductions of platelets, lymphocytes and leukocytes were grouped as hematological changes.	39.6
Hemolytic anemia	44.6
Psychosis	14.3
Seizures	5.5
Renal impairment (proteinuria)	78.0
ANA, positive	60.4

Brasil

Brasil

Polymorphisms in NAT2 (N-acetyltransferase 2) gene in patients with systemic lupus erythematosus

ABSTRACT

Objective:

Methods:

Results and conclusions: