Association between heterozygote Val92Met MC1R gene polymorphisms with incidence of melasma: a study of Javanese women population in Yogyakarta

Figures & data

Table 1 Characteristics of age, sun exposures, and family history of the two groups: with melasma and without melasma (n=158)

	Subjects		OR (95% CI)	p
	Melasma N=79 (%)	Non-melasma N=79 (%)
Mean age (years)	40.6 (SD ±6.45)	38.5 (SD ±7.48)	-	0.146
Sun exposure (minutes)
Mean exposure ≤1 hour	26 (32.91)	39 (49.37)	Ref.	0.036**
Mean exposure >1 hour	53 (67.09)	40 (50.63)	1.99 (1.04–3.78)*
Family history
No	33 (41.77)	76 (96.20)	Ref.	<0.001**
Yes	46 (58.23)	3(3.82)	35.32 (10.25–121.70)*

Notes: Ref., reference; *Chi-Square test **Significant p<0.05.

Figure 1 Sequencing results of the heterozygote Val92Met genotype of the MC1R gene polymorphisms.

Notes: The MC1R Val92Met polymorphism involved amino acid substitution from Valine to Methonine at codon 92. (A) Wild-type (homozygote) for the Val/Val genotype (Valine/Valine-GG). (B) Homozygote mutant for Met/Met genotype (Methionine/Methionine-AA). (C) Heterozygote variant for the Val/Met genotype (Valine/methionine-GA).

Figure 2 Sequencing results of the heterozygote Arg163Gln genotype of the MC1R gene polymorphisms.

Notes: The MC1R Arg163 Gln polymorphism involved amino acid substitution from Arginine to Glutamine at codon 163. (A) Wild-type (homozygote) for the Arg/Arg genotype (Arginine/Arginine-GG). (B) Homozygote mutant for the Gln/Gln genotype (Glutamine/Glutamine-AA). (C) Heterozygote variant for the Arg/Gln genotype (Arginine/Glutamine-GA).

Table 2 Association between Val92Met and Arg163Gln genotypes of MC1R gene polymorphisms and melasma

Genotype	Melasma n=79 (%)	Non-melasma n=79 (%)	OR (95% CI)	p
Val 92 Met
Val/Val (GTG/GTG)	17 (21.52)	29 (36.71)	Ref.
Val/Met (GTG/ATG)	52 (65.82)	35 (44.30)	2.53 (1.21–5.29)*	0.012**
Met/Met (ATG/ATG)	10 (12.66)	15 (18.99)	1.14 (0.42–3.09)	0.801
Arg163Gln
Arg/Arg (CGA/CGA)	20 (25.32)	16 (20.25)	Ref.
Arg/Gln (CGA/CAA)	43 (54.43)	40 (50.63)	0.86 (0.39–1.89)	0.711
Gln/Gln (CAA/CAA)	16 (20.25)	23 (29.12)	0.56 (0.22–1.39)	0.208

Notes: Ref., reference; *Chi-Square test, **Significant p<0.05.