Recessive ichthyosis congenita type II

Abstract

In the heterogeneous group of recessive congenital ichthyoses the disorder of desquamation seems to be a basic problem. Desquamation is strongly dependent on the normal lipid metabolism of the keratinocytes. We describe a group of patients who have a typical clinical picture of large scale ichthyosis and cholesterol clefts in the thickened corneal layer, evidencing a disturbance of the lipid metabolism of the skin. The corneocytes also show a thin or absent cornified envelope, which could indicate a disturbance of protein synthesis. These patients have a severe ichthyosis, but good general health and no associated symptoms. This disorder has recently been named 'ichthyosis congenita type II' by the Heidelberg group on the basis of electron microscopic findings. According to the present examination this group corresponds clinically to the currently used diagnosis 'lamellar ichthyosis'.

Development of ichthyosiform skin compensates for defective permeability barrier function in mice lacking transglutaminase 1

“…In keeping with our finding, the characteristic abnormal granules have also been recently documented in an adult LI patient with a TGase 1 mutation (45). Vacuoles or lipid droplets reported in IC type I and in some cases of IC type II seem to correspond to vacuoles seen in the cornified cells of the mature TGase 1 -/-mouse skin (14)(15)(16). The origin of those vacuoles is unknown, but some are fused with remnants of lamellar granules in the SC, suggesting that they are related to lipid metabolism.…”

Inability of keratinocytes lacking their specific transglutaminase to form cross-linked envelopes: Absence of envelopes as a simple diagnostic test for lamellar ichthyosis

“…Lamellar ichthyosis refers to a heterogeneous group of genetic skin disorders, some but not all of which are due to mutations in the TGase1 gene (19)(20)(21)(22)(23)(24)(25)(26). Some of the common features in these diseases include a defective stratum corneum with reduced barrier function (27)(28)(29) and thinning of the marginal band of the corneocyte (30). By using cultured keratinocyte strains and epidermal scales from patients with ichthyoses, we show herein that, in the absence of TGase1, no cross-linked envelopes are formed.…”

Revised nomenclature and classification of inherited ichthyoses: Results of the First Ichthyosis Consensus Conference in Sorèze 2009

“…160 The ultrastructural features of the so-called EM classification described by the Heidelberg group are based on a glutaraldehyde fixation of the skin biopsy specimen. [206][207][208][209][210] With this technique polygonal clefts in the SC can be observed as an ultrastructural key feature of TGase-1 deficiency, 211 aberrant vesicular structures may indicate NIPAL4 (;ICHTHYIN ) mutations in ARCI, 33 and trilamellar membrane aggregations in the SC and SG (EM type IV) are pathognomonic for ichthyosis prematurity syndrome. 89 Detachment of the SC from the SG with asymmetric cleavage of corneodesmosomes is a specific feature of NS.…”