The Sjögren-Larsson syndrome (SLS) is a genetically determined syndrome with autosomal recessive inheritance originally and comprehensively described from Sweden. It is characterized by the three cardinal signs congenital ichthyosis, spastic di- or tetraplegia and mental retardation.The present investigation covers all 35 SLS patients alive in Sweden in 1978 and the genetic study all 58 SLS patients born in Sweden in 1886-1977. Forty-five of these were bom in a restricted area in the northeast of Sweden and five more had ancestors from this area. This concentration is probably the result of a founder effect — transmission of the SLS gene mutation from early immigrants to this area — followed by little migration to and from this area. Ancestors of SLS patients have been traced back to an early immigrant to this area in the 14th century.The mean yearly incidences of SLS per 100.000 newborn during the years 1901-1977 were 0.6 in the whole of Sweden, 10.2 in the county of Västerbotten and 2.7 in the county of Norrbotten. The corresponding prevalence figures for SLS on 31 December 1978 were 0.4, 8.3 and 2.6 per 100.000 in these areas, respectively.The ichthyosis in the SLS was found to be congenital in the true sense of the word, as it was always seen at birth. The characteristic skin findings indicate that the use of replicas in ichthyotic patients may be a good complement to the clinical and histopathological examinations.All SLS patients had mental retardation and spastic di- or tetraplegia. The first observation of these symptoms was made between the age of 4 and 30 months.Small white glistening dots located in the ocular fundus were noted in all 30 SLS patients examined in this respect and seem to be pathognomonic for SLS.The fatty acid patterns of plasma phospholipids, cholesteryl esters, triglycerides and free fatty acids in SLS patients were examined. The results suggest that SLS is possibly a disorder of fatty acid metabolism leading to an altered composition of polyunsaturated fatty acids due to a disturbance in the A6-desaturation of essential fatty acids. / <p>Some photos have been censored.</p><p>En del foton har blivit censurerade.</p> / digitalisering@umu

Monogenic disorders, i.e., disorders caused by mutations in a single gene, are rare and clinically heterogeneous conditions. Identification of the genetic cause of monogenic traits can bring new insights into molecular pathways and disease mechanisms. The aims of the present study were to identify the mutant genes in two autosomal recessive skin disorders and to characterize the functions of the mutated genes.  In order to identify candidate genes for the two disorders whole-genome SNP analysis, homozygosity mapping and gene sequencing were used. Autosomal recessive congenital ichthyosis (ARCI) is a group of disorders characterized by extensive scaling and redness of the skin.  A subgroup of ARCI patients (n=27) was selected based on specific ultrastructural aberrations in their skin, revealed by electron microscopy. Mutations were identified in the Ichthyin gene in 93% of the selected patients, indicating a strong association between mutant Ichthyin and the specific morphological abnormalities. Ichthyin mRNA levels were shown to increase during keratinocyte differentiation in cells from healthy and affected individuals. Electron microscopy revealed a localization of ichthyin protein to keratins and desmosomes in epidermis. Staining of epidermal lipids identified aberrant lipid aggregates in skin sections of patients with Ichthyin mutations, indicating a role for Ichthyin in epidermal lipid metabolism. In twelve KLICK syndrome patients with ichthyosis, palmoplantar keratoderma and keratotic striae on joints, a single-nucleotide deletion was identified in the 5’ region of the proteasome maturation protein (POMP) gene.  The deletion caused an increase in the proportion of POMP transcripts with long 5’ UTR’s in patient keratinocytes.  Immunohistochemical analysis of differentiated skin cell layers revealed aberrant expression of POMP, proteasome subunits and the skin protein filaggrin in patients. CHOP expression, associated with endoplasmic reticulum stress, was increased in the same layers. siRNA silencing of POMP in cell cultures reduced proteasome subunit levels and induced expression of CHOP.  The results indicate that the mutation in KLICK patients causes POMP and proteasome insufficiency with subsequent cellular stress. This study conclusively contributes to the understanding of epidermal physiology and the pathogenesis of two inherited skin diseases.

<p>Hereditary ichthyosis is a collective name for many dry and scaly skin disorders ranging in frequency from common to very rare. The main groups are autosomal recessive lamellar ichthyosis, autosomal dominant epidermolytic hyperkeratosis and ichthyosis vulgaris, and x-linked recessive ichthyosis. Anhidrosis, ectropion and keratodermia are common symptoms, especially in lamellar ichthyosis, which is often caused by mutations in the transglutaminase 1 (TGM1) gene. The aim of this work was to study patients with different types of ichthyosis regarding (i) the patho-aetiology (TGM1 and electron microscopy [EM] analysis), (ii) skin signs and symptoms (clinical score and subjective measure of disease activity), (iii) quality of life (questionnaires DLQI, SF-36 and NHP and face-to-face interviews) and (iv) a search for new ways of topical treatment. Patients from Sweden and Estonia with autosomal recessive congenital ichthyosis (n=83) had a broader clinical spectrum than anticipated, but a majority carried TGM1 mutations. Based on DNA analysis and clinical examinations the patients were classified into three groups, which could be further subdivided after EM analysis. Our studies indicate that patients with ichthyosis have reduced quality of life as reflected by DLQI and by some domains of SF-36, by NHP and the interviews. All the interviewees reported that their skin disease had affected them negatively to varying degrees during their entire lives and that the most problematic period was childhood. All patients with ichthyosis use topical therapy. In a double-blind study creams containing either 5% urea or 20% propylene glycol were found inferior to a cream formulation containing lactic acid 5% and propylene glycol 20% both regarding clinical improvement and thinning of the skin barrier. Improved topical therapy may reduce the need of more toxic, oral drugs. Future studies should elucidate whether this increases the quality of life of ichthyosis patients, especially if combined with more detailed information about the aetiology and inheritance of the diseases.</p>

Hereditary ichthyosis is a collective name for many dry and scaly skin disorders ranging in frequency from common to very rare. The main groups are autosomal recessive lamellar ichthyosis, autosomal dominant epidermolytic hyperkeratosis and ichthyosis vulgaris, and x-linked recessive ichthyosis. Anhidrosis, ectropion and keratodermia are common symptoms, especially in lamellar ichthyosis, which is often caused by mutations in the transglutaminase 1 (TGM1) gene. The aim of this work was to study patients with different types of ichthyosis regarding (i) the patho-aetiology (TGM1 and electron microscopy [EM] analysis), (ii) skin signs and symptoms (clinical score and subjective measure of disease activity), (iii) quality of life (questionnaires DLQI, SF-36 and NHP and face-to-face interviews) and (iv) a search for new ways of topical treatment. Patients from Sweden and Estonia with autosomal recessive congenital ichthyosis (n=83) had a broader clinical spectrum than anticipated, but a majority carried TGM1 mutations. Based on DNA analysis and clinical examinations the patients were classified into three groups, which could be further subdivided after EM analysis. Our studies indicate that patients with ichthyosis have reduced quality of life as reflected by DLQI and by some domains of SF-36, by NHP and the interviews. All the interviewees reported that their skin disease had affected them negatively to varying degrees during their entire lives and that the most problematic period was childhood. All patients with ichthyosis use topical therapy. In a double-blind study creams containing either 5% urea or 20% propylene glycol were found inferior to a cream formulation containing lactic acid 5% and propylene glycol 20% both regarding clinical improvement and thinning of the skin barrier. Improved topical therapy may reduce the need of more toxic, oral drugs. Future studies should elucidate whether this increases the quality of life of ichthyosis patients, especially if combined with more detailed information about the aetiology and inheritance of the diseases.