Review of 52 cases with Hailey-Hailey disease identified 25 novel mutations in Chinese Han population

Two Novel and a Recurrent ATP2C1 Mutations in Chinese Population with Hailey-Hailey Disease

Purpose

Hailey-Hailey disease (HHD), also known as familial benign chronic pemphigus, is a rare autosomal dominant inherited blistering dermatosis. Pathogenic variants in ATP2C1 have been associated with HHD since 2000. This study aimed to identify the mutations in the ATP2C1 gene in two Chinese pedigrees and two sporadic cases with HHD.

Patients and Methods

Two Chinese pedigrees and two sporadic cases were included in this study. Whole-exome sequencing and Sanger sequencing were performed to detect the mutation of the ATP2C1 gene. Predictions of protein structure and function were performed using bioinformatics tools, including Mutation Taster, Polyphen-2, SIFT, and Swiss-Model.

Results

In this study, we detected three heterozygous mutations, including novel compound mutations of (c.1840-4delA and c.1840_1844delGTTGC), splice site mutation of c.1570+3A>C, and a previously known nonsense mutation c.1402C>T in the ATP2C1 gene. Combined with our previous study, ten patients with c.1402C>T mutation in the ATP2C1 gene have been identified, and all these patients originated from Jiangxi Province.

Conclusion

c.1402C>T mutation in the ATP2C1 gene was considered a regional highly prevalent mutation in the Chinese population with HHD. The results added new variants to the database of ATP2C1 mutations associated with HHD.

Two Novel Variants and One Previously Reported Variant in the ATP2C1 Gene in Chinese Hailey-Hailey Disease Patients

Hailey-Hailey disease (HHD) is a rare autosomal dominant genodermatosis. It is characterized clinically by recurrent erosions, blisters and erythematous plaques at the sites of friction and intertriginous areas. The pathogenic gene of HHD was reported to be the ATPase calcium-transporting type 2C member 1 gene (ATP2C1). In this study, genomic DNA polymerase chain reaction (PCR) and direct sequencing of ATP2C1 were performed from 3 Chinese pedigrees and 4 sporadic cases of HHD. We detected 3 heterozygous mutations, including 2 novel mutations (c.1673_1674insGTTG and c.2225A>G) and 1 recurrent nonsense mutation (c.1402C>T; NM_014382.4). The ATP2C1 gene was also screened in the asymptomatic members of pedigrees. Our results would further expand the mutation spectrum of the ATP2C1 gene and be helpful in the genetic counseling of patients with HHD.

Whole exome sequencing improves mutation detection in Hailey-Hailey disease

Hailey-Hailey disease (HHD) is an autosomal dominant monogenic disease that is defective in the ATP2C1 gene. In previous studies, Sanger sequencing was the main method applied to detect mutations in HHD patients, and no mutations in the ATP2C1 gene were found in 12-55% of those reported. The aim of our study was to carry out whole exome sequencing (WES) for the HHD patients in whom efforts to identify mutations by Sanger sequencing had failed, and to find a new pathogenic gene. WES was performed using genomic DNA from 13 HHD patients and 364 in-house healthy controls. Potential pathogenic mutations were subsequently validated by Sanger sequencing. As a result, eight mutations in the ATP2C1 gene were identified using WES. In the remaining five patients, we found one mutation in the ATP2A2 gene which was the causal gene of Darier's disease. Four patients had no detectable mutations in ATP2C1 and the other ATPase genes. Together with our previous study in 2019, the total mutation rate was calculated to be 47/52 (90.4%). These findings demonstrate that WES is capable of improving the mutation detection sensitivity in HHD compared with Sanger sequencing.

Generalized Hailey-Hailey disease: Novel splice-site mutations of ATP2C1 gene in Chinese population and a literature review

BACKGROUND

Hailey-Hailey disease (HHD; OMIM: 169600) is an autosomal dominate genodermatosis, characterized by recurrent blisters and erosions clinically and remarkable acantholysis pathologically. The underlying pathogenic factor is the mutation of ATP2C1 gene (OMIM: 604384), which encodes secretory pathway Ca²⁺ /Mn²⁺ -ATPase (SPCA1). Skin folds are the predilection site of HHD. Atypical cases with a generalized pattern have rarely been reported, making it prone to misdiagnosis.

METHODS

In this study, we presented three Chinese pedigrees of Hailey-Hailey disease with generalized skin lesions. ATP2C1 mutations were screened by DNA sequencing and their transcripts were further confirmed by minigene assay. We also performed a literature review of previously published generalized HHD over past two decades together with our cases.

RESULTS

Three splice-site mutations were identified: c.2487+1G>A, c.2126+1G>A, and c.1891-2A>G, which resulted in an exon 25-truncated transcript, two exon 22-truncated transcripts, and two exon 21-truncated transcripts, respectively. The c.2487+1G>A and the c.1891-2A>G mutations are novel mutations which have not been reported before. No clustered mutations of ATP2C1 gene were found in generalized HHD patients in literature along with our novel mutations.

CONCLUSION

We found no hot spot mutations in ATP2C1 correlated with the generalized pattern of HHD. Our study expanded the spectrum of ATP2C1 mutations, which would be useful for disease diagnosis and genetic counseling.