Investigation of the predisposing factor of pemphigus and its clinical subtype through a genome-wide association and next generation sequence analysis

BACKGROUND

Pemphigus is an autoimmune blistering disease with pemphigus vulgaris (PV) and foliaceus (PF) as the two major histological subtypes. Associations with HLA molecules have been suggested, but specific HLA risk variants as well as non-HLA risk variants remain to be discovered.

METHODS

We performed a two-stage genome-wide association study in the Chinese Han population through a genome-wide discovery analysis and follow-up validation analysis in a total number of 210 PV, 159 PF and 2493 healthy controls. HLA imputation as well as high coverage next generation sequencing based HLA genotyping was employed to investigate the association of classical HLA alleles and amino acid change.

RESULTS

We have discovered independent novel associations with PF at rs2178077 on 12q24.33, located next to RAN (P_PF = 1.57 × 10^-9 ) and rs3888722 within the MHC region (P = 6.73 × 10^-9 ). For the HLA variants, we confirmed independent genome-wide level risk associations in HLA-DQB1 and HLA-DRB1, with DQB1*05:03 to be the strongest association with PV (P = 8.59 × 10^-68 , OR = 31.16) and PF (P = 4.84 × 10^-17 , OR = 5.64). In addition, DRB1*14 was demonstrated to be a second independent variants (P = 4.2 × 10^-63 , OR = 35.47) for PV, while DRB1*04:06 was demonstrated to be the second independent signal (P = 7.44 × 10^-13 , OR = 5.58) for PF.

CONCLUSIONS

These findings advance our understanding of the genetic basis of pemphigus susceptibility and may offer opportunities for risk prediction and preventive treatment for pemphigus, in particular for PV.

No association of DNM3 with age of onset in Asian Parkinson's disease

BACKGROUND AND PURPOSE

Genetic variability in DNM3 has been shown to modify age of onset of Parkinson's disease (PD) among LRRK2 Gly2019Ser carriers in North African Arab-Berber populations. In Asian populations, the Gly2019Ser mutation is rare or absent but two other LRRK2 variants, Gly2385Arg and Arg1628PPro, increase PD risk. We aimed to determine whether the DNM3 locus was associated with age of PD onset in both carriers and non-carriers of LRRK2 risk variants in Asians.

METHODS

We analyzed the association of DNM3 rs2421947 genotypes with age of PD onset in 3645 Chinese samples, of which 369 carried at least one of two Asian LRRK2 risk variants.

RESULTS

DNM3 rs2421947 genotypes were not associated with age of PD onset in Chinese samples. We observed no heterogeneity in the effect of rs2421947 between the Asian LRRK2 risk variant carriers and non-carriers.

CONCLUSIONS

DNM3 rs2421947 was not associated with age of PD onset in LRRK2 risk variant carriers and non-carriers in Chinese samples. Further studies in other Asian populations will be of interest.