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I Hausser

Publications and source records attributed to I Hausser.

At least 37 records · Page 2Linked to original sources
PubMed1997

Mutations in the COL5A1 gene are causal in the Ehlers-Danlos syndromes I and II.

The Ehlers-Danlos syndrome (EDS) is a heterogeneous connective-tissue disorder of which at least nine subtypes are recognized. Considerable clinical overlap exists between the EDS I and II subtypes, suggesting that both are allelic disorders. Recent evidence based on linkage and transgenic mice studies suggest that collagen V is causally involved in human EDS. Collagen V forms heterotypic fibrils with collagen I in many tissues and plays an important role in collagen I fibrillogenesis. We have identified a mutation in COL5A1, the gene encoding the pro(alpha)1(V) collagen chain, segregating with EDS I in a four-generation family. The mutation causes the substitution of the most 5' cysteine residue by a serine within a highly conserved sequence of the pro(alpha)1(V) C-propeptide domain and causes reduction of collagen V by preventing incorporation of the mutant pro(alpha)1(V) chains in the collagen V trimers. In addition, we have detected splicing defects in the COL5A1 gene in a patient with EDS I and in a family with EDS II. These findings confirm the causal role of collagen V in at least a subgroup of EDS I, prove that EDS I and II are allelic conditions, and represent a, so far, unique example of a human collagen disorder caused by substitution of a highly conserved cysteine residue in the C-propeptide domain of a fibrillar collagen.

Adolescent↗
PubMed1996

Autosomal recessive cutis laxa syndrome. A case report.

Congenital cutis laxa (CCL) is a rare, genetically heterogeneous connective tissue disorder, manifested by loose, hanging skin, giving the appearance of premature aging. We report a 6-year-old female child with autosomal recessive CCL type III, to assess possible correlations between clinical, ultrastructural, cellular and biochemical features. Morphological aberrations of the elastic and collagen tissue, increased collagen I mRNA expression associated with increased protein synthesis and increased collagenase gene expression of the cutis laxa fibroblasts could be established. Our results suggest that CCL is not only a disease of the elastic fibers of the connective tissue but also of the collagen fibers, with a central role of the fibroblast.

Cells, Cultured↗
PubMed1994

Differential ultrastructural aberrations of collagen fibrils in Ehlers-Danlos syndrome types I-IV as a means of diagnostics and classification.

Among the different subtypes of Ehlers-Danlos syndrome (EDS), the dominant types I-III have, so far, been uninformative biochemically and molecular genetically, and diagnostic problems with subgroup boundaries often arise. We have investigated the ultrastructural pattern of connective tissue macromolecules in skin biopsy specimens of some 85 patients aged 4 months-54 years who exhibit clinical symptoms or the suspicion of EDS I-IV. Based on the differential features of collagen fibrils and ground substance material, four distinct groups could be established. Group I (clinically EDS type I) showed disorganized collagen bundles and dense aggregations of collagen fibrils with bizarre shapes. Group II (clinically varying from EDS types I-III) revealed collagen bundles that regularly contained numerous "composite collagen fibrils" with enlarged "flower-like" cross-sections and rope-like longitudinal sections, often associated with increased amounts of matrix substances in the form of electron-dense irregular strands and filaments in a branched network. Group III (clinically EDS types II-III) presented smaller isolated collagen flowers and ropes associated with excessive filamentous ground substance material and flocculent material. Group IV (with clinical symptoms of EDS type IV) had a dermis thinned to one third of the normal and a reduced number of collagen bundles with small diameter fibrils. In 13 patients, the abnormal ultrastructural dermal architecture did not coincide with any of these four groups or with the pattern of any other inherited connective tissue disorder. In 16 additional patients with mostly mild clinical symptoms, such as muscle weakness and small joint hyperlaxity, no ultrastructural aberrations could be found. Even though the primary defects underlying the respective aberration of the collagen fibrils are still unknown, the differential ultrastructural changes of the collagen fibrils together with clinical symptoms should, as in other heterogeneous genetic disorders, facilitate the (provisional?) classification of EDS and permit the diagnosis of individual cases.

Adolescent↗
PubMed1994

[Hyalinosis cutis et mucosae and Ehlers-Danlos syndrome. A rare combination of syndromes].

We report on a 7-year-old boy suffering from two rare genetic diseases, namely hyalinosis cutis et mucosae and Ehlers-Danlos syndrome. The diagnosis was finally established after 7 years, by means of light and electron microscopy and immunohistology. Therefore, this report deals with the typical clinical and morphological features of both genetic disorders.

Basement Membrane↗
PubMed1993

Is filaggrin really a filament-aggregating protein in vivo?

Filaggrin, a basic protein of the stratum corneum, was named as such because of its capability to aggregate keratin intermediate filaments in vitro. To investigate its filament-aggregating capability in vivo, we performed immunoelectron microscopy in three autosomal dominant genodermatoses serving as in vivo models of abnormalities of keratin filament aggregation. In bullous congenital ichthyosiform erythroderma Brocq and epidermolytic palmoplantar keratoderma Voerner suprabasal clumping of keratin filaments prevents the normal spreading of keratohyalin between keratin filaments. Keratohyalin granules, either isolated or attached to clumped keratins, were specifically labelled by the anti-filaggrin antibody, whereas tonofilament clumps did not show any reaction. In epidermolysis bullosa herpetiformis Dowling-Meara the abnormal filament aggregation occurred in basal cell keratins where no reaction of the anti-filaggrin antibody was detected. In high level keratinocytes with normal distribution of tonofilaments, normal stellate keratohyalin reacted specifically. In all instances keratin filament clumping occurred independently of, and spatially separated from, the first signs of profilaggrin synthesis and keratohyalin granule formation. Thus, in these disorders, filaggrin is not involved in filament aggregation.

Adult↗
PubMed1993

[Olmsted syndrome. Successful therapy by treatment with etretinate].

A 36-year-old North American patient has been suffering from Olmsted syndrome since early childhood. This rare inborn error of keratinization consists in pronounced, multilating keratoderma of palms and soles and associated periorificial keratoses. The patient has now been treated with etretinate for more than 6 years, resulting in a marked reduction of hyperkeratoses. Electron microscopic investigation of skin biopsies taken before and during therapy have confirmed the significant clinical improvement. Even though this retinoic acid derivative, a powerful regulating agent with a de-differentiating effect, cannot cure the basic defect, the marked hyperproliferation of the epidermis is reduced, so that terminal differentiation is delayed and thereby normalized. At the same time, the synthesis of keratinization proteins, such as keratins and keratohyalin, which is suppressed before therapy, increases. The familial connective tissue disorder existing independently of Olmsted syndrome in this patient (perhaps a mild form of Ehlers-Danlos syndrome) is not influenced by the retinoid therapy.

Adult↗
PubMed1991

Early preclinical diagnosis of dominant pseudoxanthoma elasticum by specific ultrastructural changes of dermal elastic and collagen tissue in a family at risk.

The preferred description for the Grönblad-Strandberg syndrome, pseudoxanthoma elasticum (PXE), refers only to the cutaneous aspect of the disease, although the skin is the least severely involved organ. The potential catastrophic manifestation of this heterogeneous heritable disorder is described in a dominant pedigree where mother and grandmother died because of major vascular problems. The family requested predictive testing of the three children. Diagnosis of PXE is usually performed by morphological examination of skin lesions, which reveal incrustations formed by inorganic ions (mainly calcium) and various organic (degraded?) materials in the elastin moiety of the elastic fibers. The ubiquitous elastic fibers in other organs and arteries may be similarly involved. Moreover, there is co-involvement of collagen fibrils at the electron microscopical level. The three adolescent siblings did not show any clinical PXE symptoms. However, ultrastructural investigation of overtly normal skin in predilection sites gave a positive diagnosis for this dominant PXE type. Dermal connective tissue showed a specific aberrant pattern: elastin of elastic fibers regularly contained small foci of calcification resembling those in perilesional skin of the mother and other PXE patients; in collagen bundles adjacent to altered elastic fibers, collagen fibrils occurred with thickened diameters and flower-like contours; ground substance material was increased. The possible pathogenetic mechanism and problems posed by predictive testing of adult-onset diseases are discussed.

Adolescent↗
PubMed1991

Keratohyalin granules are heterogeneous in ridged and non-ridged human skin: evidence from anti-filaggrin immunogold labelling of normal skin and skin of autosomal dominant ichthyosis vulgaris patients.

Recent biochemical and morphological investigations have provided evidence for a heterogeneous composition of keratohyalin in human skin. A major component is filaggrin. In interfollicular epidermis the heterogeneity of keratohyalin is not directly visible, whereas in normal ridged skin bicomponent keratohyalin is revealed by electron microscopy. Skin biopsies of ridged and non-ridged skin of normal individuals and patients with autosomal dominant ichthyosis vulgaris (ADI)--characterized by defective keratohyalin synthesis and lack of filaggrin--were investigated by routine transmission electron microscopy and immunogold postembedding techniques using a commercial monoclonal anti-filaggrin antibody. In normal interfollicular epidermis filaggrin labelling was demonstrated on keratohyalin granules and in the lowermost cornified cells, whereas in ADI patients crumbly keratohyalin granules were present that did not show specific labelling for filaggrin. In normal ridged skin only the major (more electron-dense) component reacted with anti-filaggrin, whereas the attached (less electron-dense) component did not react. Ridged skin of ADI patients contained globular keratohyalin that did not react with anti-filaggrin, thus corresponding to the attached keratohyalin component in normal ridged skin. Our results provide a visible counterpart to the recent biochemical investigations of keratohyalin protein heterogeneity and contribute to the understanding of terminal differentiation in human skin and of the defective keratohyalin synthesis in ADI.

Adult↗
PubMed1991

[Hyalinosis cutis et mucosae (Urbach-Wiethe disease)--ultrastructural and immunological characteristics].

In this report on a young female patient with hyalinosis cutis et mucosae (Urbach-Wiethe disease, lipoid proteinosis), we present the clinical, immunological and ultrastructural features of this inherited disorder and discuss the differential diagnosis against other interstitial connective tissue depositions. Immunologically, the most important result was the increased amount of collagen type IV at the junction zones of epidermis, dermal vessels and appendages. This was in accordance with the ultrastructural deposition of hyalin material, mainly consisting of multiplied basal laminae at the respective junction zones. The pathogenesis (gene defect or defective gene regulation?) and therapy are discussed.

Adult↗
PubMed1990

Prenatal diagnosis of genodermatoses by ultrastructural diagnostic markers in extra-embryonic tissues: defective hemidesmosomes in amnion epithelium of fetuses affected with epidermolysis bullosa Herlitz type (an alternative prenatal diagnosis in certain cases).

We report the first use of amnion epithelium for prenatal diagnosis. Prenatal diagnosis of recessive epidermolysis bullosa atrophicans generalisata gravis Herlitz type can at present be achieved with safety by detailed ultrastructural analysis of fetal skin. Because of the close developmental origin of amnion and skin, which has been elucidated by the recent development of anti-amnion antibodies against dermo-epidermal junction antigens and by their abnormal binding in epidermolysis bullosa skin, there is presumably some morphological relationship between amnion epithelium and skin. In a comparative study of extra-embryonic tissues, we found ultrastructurally complete hemidesmosomes in all 24 investigated normal amnion samples from gestational weeks 15-27, but not in 7 reflected chorion samples from weeks 16-22. The results of placental chorion samples were not reliable. Amnion of 5 fetuses affected with epidermolysis bullosa atrophicans generalisata gravis revealed only hypoplastic hemidesmosomes, the same defect as in the respective skin. In a recent case where unfortunately only non-skin material was available, a positive prenatal diagnosis of epidermolysis bullosa atrophicans gravis Herlitz was performed from the amnion material. The diagnosis was confirmed by investigation of the fetal skin after termination. Investigation of amnion membranes is therefore an alternative for prenatal diagnosis of epidermolysis bullosa atrophicans gravis Herlitz in certain cases. The possibility and limitations of the general use of amnion for prenatal diagnosis are discussed.

Amnion↗
PubMed1989

Netherton's syndrome: ultrastructure of the active lesion under retinoid therapy.

A young female patient, expressing the symptom triad of Netherton's syndrome, i.e., ichthyosis linearis circumflexa Comèl, trichorrhexis invaginata and other hair shaft defects, and atopic diathesis, has been treated successfully with the new retinoid preparation Etretin. Our electron microscopical study especially focused on the ultrastructural effect on the characteristic, active part of the skin lesions, which is only found within a narrow borderline just preceding the lesion's margin. In untreated skin, this part is characterized by dermal inflammation, immigrating inflammatory cells, and specific keratinization disturbances: synthesis of keratinization proteins is suppressed, serum exudates invade the epidermis, either filling the intercellular spaces of the upper spinous and the granular layer as finely granular, amorphous material, or they are partly phagocytosed and lie within intracellular, round-oval inclusions. The portions of the lesions lying towards the center are unspecific and represent recovery stages, ultrastructurally resembling stages of normal wound repair. Oral therapy with Etretin did not heal the basic defect, but drastically reduced exoserosis and the deposition of intra- and extracellular material. Keratinization seemed to normalize. The condition of the hair was also improved.

Acitretin↗
PubMed1989

[Successful retinoid therapy of Netherton syndrome].

A young patient with Netherton's syndrome characterized by the classic triad of ichthyosis linearis circumflexa, trichorhexis invaginata and atopy was treated with Acitretin, a new retinoid preparation: 35 mg Acitretin/day resulted in a severe, erosive dermatitis which necessitated interruption of therapy. Even with 10 mg/day the patient had intolerable irritation of the integument. After a further dosage reduction to 5 mg/day there were no obvious side effects and a long-term treatment was possible, resulting in an obvious reduction of the ichthyotic lesions and improved hair growth. Electron microscopy in the active part of the skin lesions from untreated skin revealed granular, membrane-enclosed material intracellularly and in the intercellular spaces of the granular layer. Keratinization was almost completely suppressed. Therapy with Acitretin drastically reduced the deposition of intra- and extracellular material and normalized keratinization. Our results underline the importance of starting retinoid therapy in Netherton's syndrome at a low dosage and adjusting it carefully in each case with reference to the skin manifestations and the side effects.

Acitretin↗
PubMed1988

Ultrastructure of first trimester chorionic villi with regard to the prenatal diagnosis of genodermatoses.

Hopes are held out for chorion villus sampling, a technique which is gaining more and more importance for the first trimester prenatal diagnosis of chromosomal aberrations and metabolic abnormalities. A variety of inherited skin diseases can be diagnosed postnatally and prenatally (in the second trimester) by ultrastructural diagnostic markers. For evaluation of prenatal diagnosis in the first trimester, we investigated chorionic villi derived from the trophoblast layer of the early pregnancy by light microscopy and conventional electron microscopy. The ultrastructure of the cellular layers covering the villi, i.e., the inner cytotrophoblast and the outer syncytiotrophoblast, as well as that of the connective tissue of the inner extraembryonic mesoderm, are thoroughly described in relation to the ultrastructural changes in certain genodermatoses including epidermolyses and keratinization disorders. We found that chorionic villi have only a few of the characteristics differentiated in skin, and none of the structures which are relevant to the diagnosis of genodermatoses. In our view, the ultrastructural approach is not suitable for first trimester prenatal diagnosis of genodermatoses in chorionic villi.

Chorionic Villi↗
PubMed1987

Electron microscopy as a means for carrier detection and genetic counselling in families at risk of tuberous sclerosis.

In otherwise asymptomatic parents of two unrelated children severely affected with tuberous sclerosis (TS), the ultrastructure of hypomelanotic skin lesions was investigated. In the hypomelanotic macules of both mothers of the two families, the population density of melanocytes was normal, melanization, however, was markedly suppressed. Therefore, these macules represent typical "white leaf-shaped macules" characteristic of tuberous sclerosis. Especially by applying the dihydroxyphenylalanine (DOPA) reaction to the ultrastructural level, it was possible to separate the TS-macules from the vitiliginous lesions of one father with a decrease of functional melanocytes as well as from other congenital circumscribed hypomelanoses. Thus electron microscopy in combination with the DOPA reaction may be helpful in recognizing a "forme fruste" of the dominantly inherited tuberous sclerosis (i.e. identification of white leaf-shaped macules) to enable genetic counselling and family planning by marking carriers of the mutant TS gene amongst the relatives of a patient and to exclude a sporadic mutation.

Adult↗
PubMed1987

Disseminated cicatricial pemphigoid in a child and in an adult. Ultrastructural diagnostic criteria and differential diagnosis with special reference to acquired epidermolysis bullosa.

The first case of an infant affected with a rare, disseminated variant of benign cicatricial pemphigoid is described, showing the same ultrastructural features of initial blister formation as an adult patient. These consist in edematous changes within the superficial dermis caused by vesiculation or dissolution of cellular and noncellular connective tissue elements, coalescing into subepidermal blisters. Differential diagnosis excludes other nonhereditary bullous disorders because of the ultrastructure of the dermo-epidermal junction in nascent blisters and in perilesional skin. In spite of evident clinical, histological, and immunohistological similarities as well as controversial and confusing immunological studies, acquired epidermolysis bullosa can be clearly separated from our case by a diagnostic hallmark on the electron-microscopical level, i.e., band-like IgG depositions beneath the basal lamina. This is demonstrated in comparing the two cases of disseminated cicatricial pemphigoid with three patients suffering from acquired epidermolysis bullosa, thus providing evidence that disseminated cicatricial pemphigoid and acquired epidermolysis bullosa are two distinct nosologic entities.

Adult↗
PubMedDate not supplied

Strong founder effect for a transglutaminase 1 gene mutation in lamellar ichthyosis and congenital ichthyosiform erythroderma from Norway.

Autosomal recessive congenital ichthyosis (ARCI) is a clinically heterogeneous disorder of keratinisation. It was recently shown that mutations in the transglutaminase 1 (TGM1) gene may be associated with the clinical subtypes lamellar ichthyosis (LI) and non-bullous congenital ichthyosiform erythroderma (CIE). Thirty-six Norwegian families with LI and seven with non-bullous CIE were studied with microsatellite markers linked to the TGMI gene. One common haplotype for two markers was found on 74% of disease associated chromosomes. Three individuals homozygous for the common haplotype, two affected by LI and one affected by CIE, were analysed for mutations in the TGM1 gene. All three patients were found homozygous for a single A to G transition located in the canonical splice acceptor site of intron 5. Probands from the remaining 40 families with LI and CIE were screened for this mutation and the A to G transition was found on 61 out of 72 alleles associated with LI and on 9 out of 15 alleles associated with CIE. These findings suggest a single founder mutation for the majority of patients with LI and CIE in Norway. The 2526A-->G mutation results in the insertion of a guanosine at position 877 (876insG) in the mature cDNA and the frame shift creates a premature termination at codon 293. The mutation was previously observed in one family with a resulting cDNA that included the entire intron 5. These results suggest that the mutation can result in variant transcripts in different individuals.

Alleles↗