Association Of Single Nucleotide Polymorphism Of CYP19A1 Gene And Polymorphic CAG Repeat Numbers In The Androgen Receptor Gene With Female Pattern Hair Loss In Chinese Han Ethnic Group

BackgroundFemale pattern hair loss(FPHL) is a common female hair disease, manifested as the head or front area of diffuse hair density reduced, with or without the front hairline shift. The pathogenesis of female pattern loss includes elevated androgens, iron deficiency and metabolic abnormalities, addition to genetic factors. And the androgen is the focal point now. The binding of androgen and androgen receptor can lead to the atrophy and degeneration of hair follicles. CYP19A1 gene and the androgen receptor (androgen receptor, AR) gene play an important role in the regulation and metabolism of androgen in the female body.ObjectiveOur aim is to explore the association between single nucleotide polymorphism of CYP19A1 gene, polymorphic CAG repeat numbers in the androgen receptor gene and female pattern hair loss in Chinese Han Ethnic group.Methods200 cases of Chinese Han patients with female pattern hair loss (Ludwig Ⅱ class 142 cases, Ludwig Ⅲ grade 58 cases) and 200 healthy controls were enrolled in our study, the separation and purification of genomic DNA was extracted from peripheral venous blood, the gene was amplified by PCR, SNaPshot technology was used to detect CYP19A1 gene candidate SNPs and polymorphism analysis of fluorescently was used to analyze CAG repeat length polymorphism.Result1. All SNPs are coincident with the Hardy-Weinberg equilibrium test.2. Rs6493497, rs7176005 allele frequencies were significantly different (p=0.001) between patients and normal controls:For rs6493497 patient group (A=62, G=338), the control group (A=100, G=300), p= 0.001; for rs7176005 patient group (T=62, C=338), the control group (T=100, C=300), p=0.001; in the analysis of the genotype, the genotype distributions of rs6493497 and rs7176005 were significantly different (p =0.003) between patients and normal controls:For rs6493497 patient group (AA=6, AG=50, GG=144), the control group (AA=12, AG=76, GG=112), p=0.003; for rs7176005 the patient group (TT=6, CT=50, CC=144), the control group (TT=12, CT=76, CC=112), p=0.003.3. Rs6493497, rs7176005 allele frequencies were significantly different (p=0.006) between Ludwig Ⅱ and Ludwig Ⅲ controls:For rs6493497 Ludwig Ⅱ group (A=53,G=231), Ludwig Ⅲ group (A=9,G=107), p=0.006; for rs7176005 Ludwig Ⅱ (T=53,C=231), Ludwig Ⅲ (T=9,C=107), p=0.006; in the analysis of the genotype, the genotype distributions of rs6493497 and rs7176005 were significantly different (p=0.028) between Ludwig II and Ludwig Ⅲ group:For rs6493497 Ludwig II group (AA=6, AG=41,GG=95), Ludwig Ⅲ group (AA=0,AG=9,GG=49), p=0.028; for rs7176005 Ludwig II group (TT=6, CT=41, CC=95), Ludwig III group (TT=0, CT=9, CC=49), p=0.028.4. In the analysis of linkage disequilibrium, we found that rs6493497 and rs7176005 are in the situation of complete linkage disequilibrium (D’=1, r2=1).5. There were not any other positive results in other SNPs allele frequency and genotype distribution between the two groups.6. There were no significant differences of CAG repeat in AR gene between patients and control group (patient group 23.73±2.04 and control group 23.90±2.13, p=0.481); There were no significant differences of CAG repeat between Ludwig II group and Ludwig III group (Ludwig II group 23.60 ±1.92 and Ludwig III group 24.07±2.28, p=0.164).ConclusionCYP19A1 gene rs6493497, rs7176005 locus are related to female pattern hair loss and the rs649349 genotype GG and rs7176005 genotype CC may increase the risk of female pattern hair loss in Chinese Han ethnic group; AR gene CAG repeats are not related to female pattern hair loss in Chinese Han ethnic group.