Dataset Information

A novel deletion and two recurrent substitutions on type VII collagen gene in seven Iranian patients with epidermolysis bullosa.

ABSTRACT:

Objectives

Epidermolysis bullosa is one of the most important series of mechano-bullous heritable skin disorders which is categorized into four major types according to the layer that bullae forms within basement membrane zone. In dystrophic form of the disease, blisters are made in the sublamina densa zone, at the level of type VII collagen protein which produce anchoring fibrils. Type VII collagen gene is the only responsible gene for this form. The aim of this study was to survey causative mutations of type VII collagen gene among Iranian patients with epidermolysis bullosa.

Materials and methods

For this purpose, exons 73-75 were investigated by polymerase chain reaction followed by direct sequencing.

Results

In current study, we found three different point mutations in type VII collagen alleles in 7 out of 50 patients. Four patients were homozygous for a new deletion which resulted in frame shift (p.Pro2089fs). Two patients were homozygous for a recurrent glycine substitution (p.G2031S) and one patient was detected with an allele carrying a substitution (p.R2069C).

Conclusion

The results emphasized heterogeneity in the type VII collagen gene and will provide a sign for early diagnosis and future study of the disease pathogenesis.

SUBMITTER: Hamidi AK

PROVIDER: S-EPMC5048121 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature

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Publications

A novel deletion and two recurrent substitutions on type VII collagen gene in seven Iranian patients with epidermolysis bullosa.

Hamidi Armita Kakavand AK Moghaddam Mohammad M Hatamnejadian Nasim N Ebrahimi Ahmad A

Iranian journal of basic medical sciences 20160801 8

<h4>Objectives</h4>Epidermolysis bullosa is one of the most important series of mechano-bullous heritable skin disorders which is categorized into four major types according to the layer that bullae forms within basement membrane zone. In dystrophic form of the disease, blisters are made in the sublamina densa zone, at the level of type VII collagen protein which produce anchoring fibrils. Type VII collagen gene is the only responsible gene for this form. The aim of this study was to survey caus ...[more]

PMID: 27746867

Similar Datasets

Project description:BackgroundRecessive dystrophic epidermolysis bullosa (RDEB) is an incurable disease caused by mutations in the gene encoding type VII collagen, the major component of anchoring fibrils (AF). We previously demonstrated that gentamicin produced functional type VII collagen in RDEB cells harboring nonsense mutations. Herein, we determined whether topical or intradermal gentamicin administration induces type VII collagen and AFs in RDEB patients.MethodsA double-blind, placebo-controlled pilot trial assessed safety and efficacy of topical and intradermal gentamicin in 5 RDEB patients with nonsense mutations. The topical arm tested 0.1% gentamicin ointment or placebo application 3 times daily at 2 open erosion sites for 2 weeks. The intradermal arm tested daily intradermal injection of gentamicin solution (8 mg) or placebo into 2 intact skin sites for 2 days in 4 of 5 patients. Primary outcomes were induction of type VII collagen and AFs at the test sites and safety assessment. A secondary outcome assessed wound closure of topically treated erosions.ResultsBoth topical and intradermal gentamicin administration induced type VII collagen and AFs at the dermal-epidermal junction of treatment sites. Newly created type VII collagen varied from 20% to 165% of that expressed in normal human skin and persisted for 3 months. Topical gentamicin corrected dermal-epidermal separation, improved wound closure, and reduced blister formation. There were no untoward side effects from gentamicin treatments. Type VII collagen induction did not generate anti-type VII collagen autoantibodies in patients' blood or skin.ConclusionTopical and intradermal gentamicin suppresses nonsense mutations and induces type VII collagen and AFs in RDEB patients. Gentamicin therapy may provide a readily available treatment for RDEB patients with nonsense mutations.Trial registrationClinicalTrials.gov NCT02698735.FundingEpidermolysis Bullosa Research Partnership, Epidermolysis Bullosa Medical Research Foundation, NIH, and VA Merit Award.

Project description:Dystrophic epidermolysis bullosa, a severely disabling hereditary skin fragility disorder, is caused by mutations in the gene coding for collagen VII, a specialized adhesion component of the dermal-epidermal junction zone. Both recessive and dominant forms are known; the latter account for about 40% of cases. Patients with dominant dystrophic epidermolysis bullosa exhibit a spectrum of symptoms ranging from mild localized to generalized skin manifestations. Individuals with the same mutation can display substantial phenotypic variance, emphasizing the role of modifying genes in this disorder. The etiology of dystrophic epidermolysis bullosa has been known for around two decades; however, important pathogenetic questions such as involvement of modifier genes remain unanswered and a causative therapy has yet to be developed. Much of the failure to make progress in these areas is due to the lack of suitable animal models that capture all aspects of this complex monogenetic disorder. Here, we report the first rat model of dominant dystrophic epidermolysis bullosa. Affected rats carry a spontaneous glycine to aspartic acid substitution, p.G1867D, within the main structural domain of collagen VII. This confers dominant-negative interference of protein folding and decreases the stability of mutant collagen VII molecules and their polymers, the anchoring fibrils. The phenotype comprises fragile and blister-prone skin, scarring and nail dystrophy. The model recapitulates all signs of the human disease with complete penetrance. Homozygous carriers of the mutation are more severely affected than heterozygous ones, demonstrating for the first time a gene-dosage effect of mutated alleles in dystrophic epidermolysis bullosa. This novel viable and workable animal model for dominant dystrophic epidermolysis bullosa will be valuable for addressing molecular disease mechanisms, effects of modifying genes, and development of novel molecular therapies for patients with dominantly transmitted skin disease.

Dataset Information

A novel deletion and two recurrent substitutions on type VII collagen gene in seven Iranian patients with epidermolysis bullosa.

Objectives

Materials and methods

Results

Conclusion

Publications

A novel deletion and two recurrent substitutions on type VII collagen gene in seven Iranian patients with epidermolysis bullosa.

Similar Datasets

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