Two novel ATP2C1 mutations in patients with Hailey-Hailey disease and a literature review of sequence variants reported in the Chinese population

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.

Novel and recurrent variants of ATP2C1 identified in patients with Hailey-Hailey disease

Hailey-Hailey disease (HHD) is a rare, late-onset autosomal dominant genodermatosis characterized by blisters, vesicular lesions, crusted erosions, and erythematous scaly plaques predominantly in intertriginous regions. HHD is caused by ATP2C1 mutations. About 180 distinct mutations have been identified so far; however, data of only few cases from Central Europe are available. The aim was to analyze the ATP2C1 gene in a cohort of Polish HHD patients. A group of 18 patients was enrolled in the study based on specific clinical symptoms. Mutations were detected using Sanger or next generation sequencing. In silico analysis was performed by prediction algorisms and dynamic structural modeling. In two cases, mRNA analysis was performed to confirm aberrant splicing. We detected 13 different mutations, including 8 novel, 2 recurrent (p.Gly850Ter and c.325-3 T > G), and 6 sporadic (c.423-1G > T, c.899 + 1G > A, p.Leu539Pro, p.Thr808TyrfsTer16, p.Gln855Arg and a complex allele: c.[1610C > G;1741 + 3A > G]). In silico analysis shows that all novel missense variants are pathogenic or likely pathogenic. We confirmed pathogenic status for two novel variants c.325-3 T > G and c.[1610C > G;1741 + 3A > G] by mRNA analysis. Our results broaden the knowledge about genetic heterogeneity in Central European patients with ATP2C1 mutations and also give further evidence that careful and multifactorial evaluation of variant pathogenicity status is essential.

View of the clinic, diagnosis and treatment of familial benign pemphigus (Hailey — Hailey disease). Literature review

The article describes modern views on predisposing factors, histological and genetic changes, the role of ATP2C1 encoding a mutant gene, localized on chromosome 3 in the pathogenesis of Hailey — Hailey disease. Diagnostic criteria, differential diagnostics with other diseases and methods of modern treatment of this disease are presented.

Identification of 2 Novel Mutations in ATP2C1 Gene in Hailey-Hailey Disease and a Literature Review of Variations in a Chinese Han Population

Background

Hailey-Hailey disease (HHD) is a rare autosomal dominant skin condition. The ATP2C1 gene was identified as the defective gene in HHD. To date, 166 pathogenic mutations in ATP2C1 have been observed worldwide. The aim of this study was to identify variations in HHD and summarize the features of the mutations identified in China.

Material/Methods

We examined 2 familial and 2 sporadic cases of HHD. Genomic DNA polymerase chain reaction and direct sequencing of the ATP2C1 were performed from HHD patients, unaffected family members, and 200 healthy individuals. We also searched the published literature for data about the ATP2C1 gene using PubMed and the Chinese Biological Medicine Database.

Results

We detected 3 heterozygous mutations, including 2 novel frameshift mutations (c.819insA (273LfsX) and c.1264insTAGATGG (421LfsX)) and 1 recurrent nonsense mutation (c.115C>T (R39X)). To the best of our knowledge, 90 different mutations (including our current results) have been reported in China, all of which occurred in the Chinese Han population.

Conclusions

Our data may add to the existing list of ATP2C1 mutations and provide new insight into genetic variants of HHD in China.

ATP2C1 gene mutations in Hailey-Hailey disease and possible roles of SPCA1 isoforms in membrane trafficking

ATP2C1 gene codes for the secretory pathway Ca(2+)/Mn(2+)-ATPase pump type 1 (SPCA1) localizing at the golgi apparatus. Mutations on the human ATP2C1 gene, causing decreased levels of the SPCA1 expression, have been identified as the cause of the Hailey-Hailey disease, a rare skin disorder. In the last few years, several mutations have been described, and here we summarize how they are distributed along the gene and how missense mutations affect protein expression. SPCA1 is expressed in four different isoforms through alternative splicing of the ATP2C1 gene and none of these isoforms is differentially affected by any of these mutations. However, a better understanding of the tissue specific expression of the isoforms, their localization along the secretory pathway, their specific binding partners and the role of the C-terminal tail making isoforms different from each other, will be future goals of the research in this field.