Ichthyosis X-linked

Recessive X-linked ichthyosis (RXLI) steroid sulfatase deficiency STS Xp22.32 308100... 

Recessive X-linked ichthyosis (RXLI) is a dermatological condition that is caused by steroid sulfatase deficiency (STSD), although the mechanism by which the deficiency causes the characteristic scaly skin has not been adequately explained. RXLI is the most common genetic disorder of steroid metabolism, affecting about 1 2000 males. Epstein and workers [16] first demonstrated that serum cholesterol sulfate was elevated in the condition, and this compound has become the preferred analyte for diagnosis. The serum level is more than tenfold greater than normal in the condition. 

Epstein EH Jr, Krauss RM, Shackleton CH (1981) X-linked ichthyosis increased blood cholesterol sulfate and electrophoretic mobility of low-density lipoprotein. Science 214 659-660... 

Shackleton CH, Reid S (1989) Diagnosis of recessive X-linked ichthyosis quantitative HPLC/ mass spectrometric analysis of plasma for cholesterol sulfate. Clin Chem 35 1906-1910... 

In recessive X-linked ichthyosis, the amount of cholesterol sulfate in the stratum corneum is increased due to a deficiency in cholesterol sulfatase deficiency [69,70], Lipid analysis of scales reveals a nearly 10-fold increase in the cholesterol sulfate to free cholesterol ratio as compared to healthy stratum corneum [71]. Previous x-ray diffraction studies on isolated ceramide mixtures revealed that increased cholesterol sulfate levels induce the formation of a fluid phase, which is likely to reduce the skin barrier function [72]. 

Cholesterol sulfate is another intercellular lipid. Addition of low levels of cholesterol sulfate, as observed in normal healthy stratum corneum, to lipid mixtures has little effect on the phase behavior at room temperature. However, addition of high levels of cholesterol sulfate, at levels similar to that observed in the skin disease recessive X-linked ichthyosis, promotes the formation of the long periodicity phase, induces the formation of a fluid phase, and increases the solubility of cholesterol in the lamellar phases [72,80],... 

Zettersten, E., et al. Recessive x-linked ichthyosis Role of cholesterol-sulfate accumulation in the barrier abnormality. J Invest Dermatol 111 784. 

Rehfeld, S.J., et al. 1988. Calorimetric and electron spin resonance examination of lipid phase transitions in human stratum corneum Molecular basis for normal cohesion and abnormal desquamation in recessive X-linked ichthyosis. J Invest Dermatol 91 499. 

Williams, M.L., and P.M. Elias. 1981. Stratum corneum lipids in disorders of cornification Increased cholesterol sulfate content of stratum corneum in recessive x-linked ichthyosis. J Clin Invest 68 1404. 

An accumulation of scales on the skin surface may be due to either an increased production of corneocytes, such as in psoriasis, or to a delayed desquamation. It may be predicted that conditions with delayed desquamation, once their pathophysiology on the molecular level is understood, will be highly informative with regard to the understanding of desquamation. Two such conditions are recessive X-linked ichthyosis (RXI) and lamellar ichthyosis. 

Koppe, G., Marinkovic-Ilsen, A., Rijken, Y., and De-Groot, W.R, X-linked ichthyosis. A sulfatase... 

X-linked Ichthyosis Sjogren - Larsson Lamellar Ichthyosis Vohwinkel syndrome I. Bullosa Siemens Epidermolytic PPK Pachonychia congen EHK (I. Bullosa) Palmopl. Keratoderma GABEB... 

FIGURE 8.2 Extremities showing (a) ichthyosis vulgaris in a 40-year-old woman and (b) X-linked ichthyosis in a 20-year-old man (from the author s files). 

Accumulates in stratum corneum of patients with X-linked ichthyosis 13... 

Ichthyosis vulgaris X-Linked ichthyosis Lamellar ichthyosis (nonbullous ichthyosiform erythroderma) Epidermolytic hyperkeratosis (bullous ichthyosis)... 

Shapiro, L. and Weiss, R., X-linked ichthyosis due to steroid sulfatase deficiency, Lancet, 14, 70, 1978. 

Ibsen, H., Brandrup, F., Blaabjerg, I., and Lykkesfeldt, G., Lipoprotein electrophoresis in recessive x-linked ichthyosis, Acfa Derm. Venereol., 66, 59, 1986. 

Zettersten, E., Man, M.-Q., Sato, J., Denda, M., Farrell, A., Ghadially, R., Williams, M., Feingold, K., and Elias, R, Recessive x-linked ichthyosis role of cholesterol sulfate accumualtion in the barrier abnormality, J. Invest. Dermatol., Ill, 784, 1998. 

Lykkesfeldt, G. and Hoyer, H., Topical cholesterol treatment of recessive x-linked ichthyosis, Lancet, 2, 1337, 1983. 

Abnormalities in lipid lamellar structure or corneodesmolysis are apparent in scaling disorders like X-linked Ichthyosis, atopic dry skin, or in winter xerosis.2,10 Susceptibility to dry skin also shows a tendency to increase with age.3 Exposure to dry environment or extreme shifts in external humidity produces important alterations in underlying skin. Dry environment stimulates epidermal hyperplasia and early markers of inflammation. Shift in external humidity induces a profound defect in... 

Atperin, E. S and Shapiro, L. J. 1997). Characterization of point mutations in patients with X-linked ichthyosis. /. BroJ. Orem. 172, 20756 20763. 

Any disruption in the biosynthetic pathway will lead to very low maternal serum UE3. Conditions that cause disruption include fetal anencephaly, placental sulfatase deficiency, fetal death, chromosome abnormalities, molar pregnancy, and Smith-Lemlit Opitz syndrome (SLOS). Placental sulfatase deficiency presents in the infant as X-linked ichthyosis. It is present in approximately 1 in every 2000 males. Because of the lack of uEj, the mother often has delayed onset of labor. The cesarean section rate is significantly higher in these mothers. SLOS is a serious, rare birth defect that is the result of an inborn error in cholesterol metabolism, 7-dehydrosterol-7-reductase deficiency. Down syndrome leads to a modest decrease in uEj. Screening for Down syndrome is now the most common application of uEs measurements. ... 

Crawfurd, M. D., Review Genetics of steroid sulfatase deficiency and X-linked ichthyosis. J. Inherited Metab. Dis. 5, 153-163 (1982). 

Shapiro, L. J., Steroid sulfatase deficiency and X-linked ichthyosis. Clin. Biochem. 12,205-270... 

A third physiological role postulated for CS involves the stratum comeum of the skin. CS is present in this layer, and apparently contributes to the intercellular lipid [134]. It may promote cellular adhesion in the stratum comeum because a 5-fold increase in CS content has been found in a form of X-linked ichthyosis characterized by steroid sulfatase deficiency [135,136],... 

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