Mutations in the ATP2C1 gene in Chinese patients with Hailey-Hailey disease

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.

A novel mutation in the ATP2C1 gene is associated with Hailey-Hailey disease in a Chinese family

BACKGROUND

A three-generation Chinese family with Hailey-Hailey disease (HHD) was identified and characterized. The proband developed HHD with severe recurrent blisters and crusted erosions involving the body folds. Skin biopsy studies showed epidermal hyperkeratosis and defects in cell-to-cell adhesion. Three other members in the family were also affected with HHD and had the same clinical manifestations. The purpose of this study was to identify the pathogenic gene or mutation in the family.

METHODS

All exons and exon-intron boundaries of ATP2C1 were polymerase chain reaction (PCR) amplified and sequenced with DNA samples from the proband. Restriction fragment length polymorphism (RFLP) analysis for the intron 23-exon 24 boundary of ATP2C1 was performed in all family members and in 100 normal control subjects.

RESULTS

A novel 2-bp deletion (c.2251delGT) was detected in exon 24 of the ATP2C1 gene. The mutation was present in the three other affected family members and in two asymptomatic young carriers, but not in the other normal family members or the 100 normal controls. The mutation resulted in a frameshift change and led to the formation of a premature termination codon (PTC) four amino acid residues downstream from the sixth transmembrane domain.

CONCLUSIONS

Our results indicate that the novel c.2251delGT (p.V751fs) mutation in the ATP2C1 gene is responsible for HHD in this Chinese family. This study expands the spectrum of ATP2C1 mutations associated with HHD.

Molecular and clinical characterization in Japanese and Korean patients with Hailey-Hailey disease: six new mutations in the ATP2C1 gene

BACKGROUND

The autosomal dominant disorder Hailey-Hailey disease (HHD) results from mutations in the ATP2C1 gene, which encodes the human secretory pathway Ca2+/Mn2+ -ATPase protein 1. To date, over 90 pathological mutations scattered throughout ATP2C1 have been described with no indication of mutational hotspots or clustering of mutations. No paradigm for genotype-phenotype correlation has emerged.

OBJECTIVES

To determine the pathogenic ATP2C1 abnormality in additional patients with HHD in order to provide further contributions to the understanding of the molecular basis of this disorder and to add the data to the known mutation database.

METHODS

In this study, we investigated eight unrelated Japanese and Korean patients with HHD. We performed direct nucleotide sequencing of the ATP2C1 gene in all patients and RT-PCR analysis, using RNA extracted from a skin biopsy, in a patient with the mildest clinical features.

RESULTS

We identified seven different heterozygous mutations in seven of the eight investigated patients, including three new single nucleotide deletion/duplication mutations: c.520delC; c.681dupA; c.956delC, three new donor splice site mutations: c.360+1G>C; c.899+1G>T; c.1570+2T>C, as well as a previously described nonsense mutation: p.Arg153X. RT-PCR analysis in the mildest affected patient with a heterozygous c.360+1G>C mutation, demonstrated expression of a short in-frame mutant transcript with exon 5 skipping, which may account for the mild phenotype.

CONCLUSIONS

The results expand the known mutation spectrum in HHD and show the importance of RNA analysis for understanding the genotype-phenotype correlations more precisely.

Genetic diagnosis in a Chinese Hailey-Hailey disease pedigree with novel ATP2C1 gene mutation

Hailey-Hailey disease (HHD) is an autosomal dominant skin disorder characterized by recurrent eruption of vesicles and bullae at the sites of friction and in the intertriginous areas. Mutations in the ATP2C1 gene encoding the human secretory pathway calcium ATPase 1 (hSPCA1) have been identified as the causative mutations in HHD. In this study, we used direct sequencing and restriction endonuclease digestion to analyze mutations of the ATP2C1 gene in a Chinese three-generation pedigree. A heterozygous T-to-C transition at nucleotide 1004 in exon 12 of ATP2C1 gene was detected. After summarizing the reported cases with ATP2C1 mutation, we concluded that the T1004C transition resulted in a novel missense mutation of leucine condon (CTG) to proline (CCG) at amino acid residue 335(L335P) in hSPCA1. Here, a genetic diagnosis was made for the proband's daughter before the clinical presentation. The study realized the molecular diagnosis in the HHD pedigree. Our findings should be useful for genetic counseling and prenatal diagnosis for the affected family and in demonstrating the critical role of the ATP2C1 gene in the pathogenesis of HHD further.