Darier-White disease and dermatofibrosarcoma protuberans

Whole-transcriptome sequencing identifies postzygotic ATP2A2 mutations in a patient misdiagnosed with herpes zoster, confirming the diagnosis of very late-onset segmental Darier disease

An 82-year-old female patient presented with a recent onset of painful skin lesions in unilateral distribution on the abdominal area following the lines of Blaschko; the initial diagnosis of Varicella-zoster infection was made. However, because the individual lesions appeared as hyperkeratotic papules and were unresponsive to antiviral therapy, a skin biopsy was performed, which revealed hyperkeratosis, suprabasal acantholysis and dyskeratosis with corps ronds and grains, consistent with acantholytic dyskeratotic acanthoma. Since this entity has been associated with Darier disease, whole transcriptome sequencing by RNA-Seq was performed on RNA isolated from a lesion as well as from adjacent normal appearing skin, and a recently developed bioinformatics pipeline that can identify both genomic sequence variants and the presence of any of over 900 viruses was applied. Two pathogenic missense mutations in the ATP2A2 gene were identified in the lesional but not in normal appearing skin, and no evidence of Varicella-Zoster infection was obtained. These findings confirm the diagnosis of segmental Darier disease due to postzygotic mutations in the ATP2A2 gene, and attest to the power of a novel single-step application of RNA-Seq in providing correct diagnosis in this rare genodermatosis.

Darier disease: A rare genodermatosis

Darier disease (DD), also known as keratosis follicularis or dyskeratosis follicularis, is a rare autosomal dominant genodermatosis with high penetrance and variable expressivity. It is caused by mutations of ATP2A2 gene which encodes the sarco/endoplasmic reticulum Ca²⁺ ATPase isoform 2. It is clinically manifested by hyperkeratotic papules primarily affecting seborrheic areas on the head, neck and thorax, with less frequent involvement of the oral mucosa. When oral manifestations are present, they primarily affect the palatal and alveolar mucosa, are usually asymptomatic and are discovered in routine dental examination. Histologically, the lesions show suprabasal clefts with acantholytic and dyskeratotic cells. We present a case of 35-year-old female patient with typical clinical and histological features of DD.

Dyskeratosis follicularis disease: case reports and review of the literature

BACKGROUND

Dyskeratosis follicularis (Darier's disease) is rare autosomal dominant disease characterized by the loss of adhesion between epidermal cells and by abnormal keratinization.

METHODS

We performed a retrospective study of all the patients diagnosed with Darier's disease at the Department of Dermatology of Charles Nicolle Hospital of Tunis, between 1971 and 2002.

RESULTS

During the observation period, we identified 12 patients with Darier's disease; five males and seven females with a mean age of 17.36 years. No family history was found in eight patients. Skin lesions in the form of keratotic papules were noted in seborrhoeic areas, essentially the face (nine patients), chest and scalp. Seven patients had nail lesions. UV light exposure exacerbated the disease symptoms in seven cases. The patients were treated with topical and systemic retinoids (six cases).

CONCLUSION

Although Darier's disease has a chronic course, most patients manage to lead a relatively normal life. Treatment is usually unsatisfactory despite much progress in understanding of the underlying abnormalities in Darier's disease.