High levels of oxysterol sulfates in serum of patients with steroid sulfatase deficiency.

Steroid sulfatase (STS) deficiency is the underlying cause of the skin condition known as recessive X-linked ichthyosis (RXLI). RXLI patients show scales on their skin caused by high concentrations of cholesterol sulfate (CS), as they are not capable of releasing the sulfate group from its structure to obtain free cholesterol. CS has been reported, so far, as the sole sulfated steroid with increased concentrations in the blood of RXLI patients. A non-targeted LC-MS approach in negative mode detection (LC-MS precursor ion scan mode) was applied to serum samples of 12 RXLI patients and 19 healthy males. We found that CS was not the only sulfated compound consistently elevated in RXLI patients, because a group of compounds with a m/z of 481 was found in high concentrations too. Further LC-MS/MS demonstrated that the main contributor to the m/z 481 signal in RXLI serum is 27-hydroxycholesterol-3-sulfate (27OHC3S). Accordingly, a new method for 27OHC3S quantification in the context of RXLI has been developed and validated. Other hydroxycholesterol sulfate compounds were elevated as well in RXLI patients.

[Lipoprotein and apolipoprotein electrophoresis in X-chromosome recessive ichthyosis]. / Lipoprotein- und Apolipoproteinelektrophorese bei X-chromosomalrezessiver Ichthyose.

BACKGROUND AND OBJECTIVE: The clinical differentiation of the hereditary ichthyosis forms is difficult and without laboratory markers hardly possible. Serum lipoprotein electrophoresis is one tool for detecting patients with recessive X-linked ichthyosis (XRI). Compared to controls, XRI patients show elevated electrophoretic mobilities of low density (LDL) and very low density lipoproteins (VLDL). This change in pattern is only partially explained by the increased LDL cholesterin sulfate concentration and is the subject of this study. PATIENTS/METHODS: Patients suffering from XRI and ichthyosis vulgaris, healthy controls. SDS-PAGE-electrophoresis and isoelectric focusing for detection of XRI-associated variations in apolipoproteins apo B-100, apo C-III and apo E. RESULTS: XRI-associated apolipoprotein variants were not found. In contrast to the literature, an increased electrophoretic mobility was also observed for HDL (high density lipoproteins) from XRI patients. CONCLUSIONS: The underlying cause of the increased electrophoretic mobility of VLDL and HDL in XRI patients remains unclear. Future studies should investigate other apolipoproteins and verify the cholesterin sulfate concentrations reported for VLDL and HDL from XRI patients.

X-linked ichthyosis: relation between cholesterol sulphate, dehydroepiandrosterone sulphate and patient's age.

Steroid sulphatase deficiency is a feature of recessive X-linked ichthyosis (RXLI) that causes the accumulation of sulphated steroids (SS) in various organs and cells. In a previous study, we detected elevated cholesterol sulphate (CS) and dehydroepiandrosterone sulphate (DHEAS) serum levels in a group of 15 RXLI patients selected in a narrow age range. In the present study both CS and DHEAS serum levels were qualitatively and quantitatively determined using gas-chromatographic analysis in a group of 33 RXLI patients ranging in age from 3 to 70 years. The levels of CS and DHEAS were significantly increased in all patients. Variations in SS were related both to patients' ages and clinical course of the disease; Serum SS levels start to increase in early infancy, peak at puberty, remain elevated in adults and decrease slightly in the elderly.

Very low maternal serum unconjugated estriol and prenatal diagnosis of steroid sulfatase deficiency.

Twenty-four women out of 7,875 pregnant women who enrolled in a prenatal screening program showed extremely low levels of unconjugated estriol (< 0.15 MOM). In 19 cases, intrauterine fetal death was reported. In 1 case anencephalus was detected. In the remaining 4 cases apparently normal healthy babies (1 female and 3 males) were born following uneventful pregnancies. Physical examination of the 3 boys at 4-6 weeks revealed mild ichthyosis compatible with the X-linked type. Two of them had a positive family history of X-linked ichthyosis. The examination of the girl did not reveal any significant findings. In both cases in which amniocentesis was performed, low levels of steroid sulfatase and arylsulfatase C were found. The prevalence of X-linked ichthyosis in this study is higher than previously reported, i.e. 1:1,300 males. Our results suggest that the prenatal screening program for neural tube defects and for Down's syndrome is useful for the prenatal detection of X-linked ichthyosis as well. These results are in accordance with two recent reports. The implications regarding genetic counseling are discussed.

Hypogonadotrophic hypogonadism with hyposmia, X-linked ichthyosis, and renal malformation syndrome.

OBJECTIVE: The aim of this study was the endocrinological, enzymatic, and genetic evaluation of a family with a complex syndrome associating hypogonadotrophic hypogonadism with hyposmia, X-linked ichthyosis and renal malformation. DESIGN: Hypothalamic-pituitary-testicular function, olfaction, steroid sulphatase activity, and morphological renal studies were assessed. DNA molecular analyses were carried out in all the patients. PATIENTS: Two brothers and their maternal uncle showed the clinical picture of congenital ichthyosis, hypogonadism, hyposmia and unilateral renal maldevelopment. MEASUREMENTS: LH and FSH were determined by RIA basally and after GnRH stimulation, and the test repeated after a period of GnRH priming. Testosterone response to hCG was measured. Arylsulphatase C assay was performed as a measure of steroid sulphatase activity. DNA amplification analysis and Southern blot analysis of four Xp22.3 loci were performed. RESULTS: Low levels of gonadotophins, basally and after acute GnRH, increased clearly after GnRH priming. Low testosterone levels increased promptly after hCG. Subnormal levels of arylsulphatase C were detected. Hyposmia and renal hypoplasia or aplasia were demonstrated. A large Xp 22.3 deletion including the genes responsible for X-linked ichthyosis (steroid sulphatase deficiency) and Kallmann syndrome was demonstrated. CONCLUSIONS: The absence of the gene encoding steroid sulphatase accounts for the X-linked ichthyosis in these patients, whereas the absence of the Kallmann syndrome gene accounts for hypogonadism, anosmia and for the single kidney found in two of the three patients.

Increased levels of DHEAS in serum of patients with X-linked ichthyosis.

The metabolic basis of X-linked ichthyosis is a deficiency of steroid sulphatase, a microsomal enzyme which removes sulphate groups from sulphated steroids. We report on a carefully controlled group of 15 patients with recessive X-linked ichthyosis, selected in a narrow age range (22-33 years), in whom, through the use of gas chromatographic analysis and conventional radioimmunoassay, we have measured not only elevated serum cholesterol sulphate levels but also significantly elevated serum dehydroepiandrosterone sulphate levels. The latter finding has been controversial in previous reports. We believe that the radioimmunoassay procedure generally used should be held responsible for such controversy since it often gives rise to false positive and/or false negative values. Gas chromatography, although more exacting, appears to be far more reliable for the assessment of elevated serum dehydroepiandrosterone.