11/389. Striate palmoplantar keratoderma resulting from desmoplakin haploinsufficiency. Recently, the first example of a human mutation in the gene encoding the desmosomal plaque protein, desmoplakin, has been described in a patient with autosomal dominant striate palmoplantar kerato-derma. We now report a further case of a desmoplakin mutation in a proband with striate palmoplantar keratoderma that also results in a null allele and haploinsufficiency. The mutation was a heterozygous G > A transition at the donor 1 site of intron 7 of the desmoplakin gene (939 1 G > A; Genbank M77830). The aberrant splicing leads to retention of the entire intron 7, which contains a premature termination codon within the N-terminal domain of the peptide. Because the mutant null allele could not be identified on cDNA sequencing, we determined by polymerase chain reaction the exon-intron organization of the desmoplakin gene to facilitate analysis of genomic dna. The gene spans approximately 45 kb of chromosome 6 and comprises 24 exons ranging in size from 51 bp to 3922 bp. We have also characterized fully the 3'UTR of the desmoplakin cDNA. This study demonstrates the relevance of haploinsufficiency for desmoplakin in the pathogenesis of this genodermatosis. Assessment of family members bearing the mutant allele also emphasizes the significance of an individual's age and exposure to skin trauma in manifesting full phenotypic expression of the disorder. ( info) |
12/389. A connexin 26 mutation causes a syndrome of sensorineural hearing loss and palmoplantar hyperkeratosis (MIM 148350). We report a missense mutation in the connexin 26 gene (GJB2) in a family with an autosomal dominant syndrome of hearing loss and hyperkeratosis. The affected family members have high frequency, slowly progressive, bilateral, sensorineural hearing loss and palmoplantar hyperkeratosis. The mutation causes an amino acid substitution (G59A), which may disrupt a reverse turn in the first extracellular loop of connexin 26. Connexin 26 mutations have been reported in syndromes of deafness and palmoplantar keratoderma. These data provide additional evidence for the role of connexin 26 in syndromes of this type. ( info) |
13/389. Palmoplantar keratoderma (Voerner) with composite keratohyalin granules: studies on keratinization parameters and ultrastructures. A case of the Voerner type palmoplantar keratoderma was studied for abnormalities of keratinization parameters. An enzyme and materials used to build the marginal band or cellular envelope of the cornified cell were all abnormally expressed; i.e. transglutaminase I (TGK), loricrin, and involucrin were abnormally immunostained. In the normal controls, their expression was limited to the upper epidermis, mainly in the granular layer. In the lesional skin, they were detected from the suprabasal layer to the lower horny layer. Filaggrin, the protein of the keratohyalin granule, was also expressed more widely than in controls. Ultrastructural abnormalities included a significantly higher frequency of composite keratohyalin granules than controls, early formation of a marginal band in the midepidermis, and, most remarkably, the clumping of tonofilaments causing vacuolization of the cytoplasm of affected keratinocytes. ( info) |
14/389. An SRY-negative XX male with Huriez syndrome. This report studies a 42-year-old 46,XX patient affected by palmoplantar keratoderma. clinically classified as Huriez syndrome. The patient showed a male phenotype with apparently normal male features including testicular development. Cytogenetic and chromosomal painting analysis excluded the presence of translocation of the y chromosome. PCR analysis of genomic dna failed to detect the presence of the testis-determining gene, SRY. The presence of other Y-chromosome genes, known to be involved in testicular maturation and spermatogenesis, has also been analyzed. The data suggest that the sex reversal in this 46,XX male patient is due to a defect on a yet unidentified autosomal or X-linked sex-determining gene. The relationship between the sex reversion and the presence of sclerotylosis is discussed. ( info) |
15/389. Transgrediens et progrediens palmoplantar keratoderma (Greither's disease) with particular histopathologic findings. We describe a patient with transgrediens et progrediens palmoplantar keratoderma (Greither's disease). Ten of the 25 members of this patient's family in six consecutive generations were affected by the disorder. The pedigree was consistent with an autosomal dominant inheritance pattern, with variable penetrance. The proband's physical examination showed typical signs of Greither's disease. The most striking findings were seen in histopathologic study and consisted of round, focal areas of orthohyperkeratosis located on delled areas of the epidermis. These histopathologic features were present in both the lesions of the palms and dorsum of the hands. We review the clinical manifestations and histopathologic findings of this particular variant of palmoplantar keratoderma and the differential diagnosis. ( info) |
16/389. A mutation in the V1 domain of K16 is responsible for unilateral palmoplantar verrucous nevus. Palmoplantar keratodermas are a group of heterogeneous diseases characterized by thickening, and marked hyperkeratosis, of the epidermis of the palms and soles. Palmoplantar keratodermas can be divided into four major classes: diffuse, focal, punctate, and palmoplantar ectodermal dysplasias. All forms are genetic diseases inherited as autosomal dominant disorders. We studied a patient exhibiting a localized thickening of the skin in parts of the right palm and the right sole, following Blaschko's lines, that does not fit into any classes already described. We sequenced the keratin 16 cDNA derived from skin biopsy material from affected and non affected palms. The keratin 16 cDNA sequence from lesional epidermis showed a 12 base pair deletion (309-320del), which deletes codons 104-107. The mutation is predicted to delete four amino acids, GGFA, from the V1 domain of the keratin 16 polypeptide, close to the 1A domain. Full-length keratin 16 cDNA sequence derived from the unaffected palm was completely normal, consistent with a postzygotic mutation as is suggested by the mosaicism observed. We defined this new clinical entity, "unilateral palmoplantar verrucous nevus", rather than localized or focal epidermolytic palmoplantar keratodermas, as the lesions are present only on one side of the body and follow Blaschko's lines. This study is a report of a mosaic mutation in keratin 16 and also the association of a mutation in the V1 domain of a type I keratin associated with a human disease. ( info) |
17/389. Implantable defibrillator therapy in Naxos disease. Naxos disease is a unique form of right ventricular cardiomyopathy with a high prevalence of malignant ventricular arrhythmias, including sudden cardiac death. As a hereditary systemic disease confined to a small island, it has been closely studied over the last 15 years. The implantation of an automatic defibrillator provides an alternative form of antiarrhythmic management to improve life expectancy in these high risk cardiac patients. We present the first two Naxos disease patients with malignant ventricular arrhythmias who had defibrillator implantation. ( info) |
18/389. Transient reactive papulotranslucent acrokeratoderma associated with cystic fibrosis. A 20-year-old female with cystic fibrosis presented with a white marginal palmar eruption after exposure to water. There was no family history of keratoderma. A biopsy showed hyperkeratosis around dilated eccrine ostia. These features are similar to a recently described condition, transient reactive papulotranslucent acrokeratoderma. This is thought to be a variant of hereditary papulotranslucent acrokeratoderma, one of the punctate keratodermas. association with cystic fibrosis has not been described previously. ( info) |
19/389. Papular palmoplantar hyperkeratosis following chronic medical exposure to arsenic: human papillomavirus as a co-factor in the pathogenesis of arsenical keratosis? This study presents the case of a 38-year-old patient from pakistan with vitiligo, who developed multiple verrucous papules on the palms and soles several years after receiving "herbal treatment" from a travelling Indian doctor for a period of 12 months. Histopathological examination showed changes consistent with the diagnosis of arsenical keratosis. Molecularbiological examination of a skin biopsy detected an atypical human papillomavirus. This observation supports the concept of human papillomavirus as a co-factor in the pathogenesis of premalignant arsenic-induced skin tumours. ( info) |
| Olmsted syndrome is a rare keratinization disorder; 18 cases have been published so far. It associates a mutilating cogenital palmoplantar keratoderma with periorificial erythematokeratotic lesions. We report herein two new unrelated male children with Olmsted syndrome (OS), one of whom was studied by light and electron microscopy. Our histological, immunohistochemical, and ultrastructural findings suggest that this disease is related to epidermal hyperproliferation. We present herein a review of the twenty cases published so far and discuss the major clinicopathological and genetic features of this disease. ( info) |