Further insights into implications of undetectable or very low unconjugated estriol in maternal serum during the second trimester

X-linked ichthyosis: Molecular findings in four pedigrees with inconspicuous clinical manifestations

Background

X‐linked ichthyosis (XLI) is the second most common type of ichthyosis, which is characterized by wide and symmetric distribution of adherent, dry, and polygonal scales on the skin. Steroid sulfatase (STS) gene, which is located at chromosome Xp22.31, has been identified as the pathogenic gene of XLI.

Methods

In this study, chromosome karyotype analysis, bacterial artificial chromosomes‐on‐Beads™ (BoBs) assay, fluorescence in situ hybridization (FISH), and single nucleotide polymorphism array (SNP‐array) were employed for the prenatal diagnoses in three pregnant women with high‐risk serological screening results and a pregnant woman with mental retardation.

Results

STS deletion was identified at chromosome Xp22.31 in all four fetuses. Postnatal follow‐up confirmed the diagnosis of ichthyosis in two male fetuses and revealed normal dermatological manifestations in other two female fetuses carrying ichthyosis.

Conclusion

The results of the present study demonstrate that a combination of karyotypying, prenatal BoBs, FISH, and SNP‐array may avoid the missed detection of common microdeletions and ensure the accuracy of the detection results, which provides a feasible tool for the reliable etiological diagnosis and better genetic counseling of XLI.

X linked recessive ichthyosis: Current concepts

In the present review, we describe the most important aspects of the X-linked ichthyosis (XLI) and make a compilation of the some historic details of the disease. The aim of the present study is an update of the XLI. Historical, clinical, epidemiological, and molecular aspects are described through the text. Recessive XLI is a relatively common genodermatosis affecting different ethnic groups. With a high spectrum of the clinical manifestations due to environmental factors, the disease has a genetic heterogeneity that goes from a point mutation to a large deletion involving several genes to produce a contiguous gene syndrome. Most XLI patients harbor complete STS gene deletion and flanked sequences; seven intragenic deletions and 14 point mutations with a complete loss of the steroid sulfatase activity have been reported worldwide. In this study, we review current knowledge about the disease.

Role of cholesterol sulfate in epidermal structure and function: lessons from X-linked ichthyosis

X-linked ichthyosis is a relatively common syndromic form of ichthyosis most often due to deletions in the gene encoding the microsomal enzyme, steroid sulfatase, located on the short area of the X chromosome. Syndromic features are mild or unapparent unless contiguous genes are affected. In normal epidermis, cholesterol sulfate is generated by cholesterol sulfotransferase (SULT2B1b), but desulfated in the outer epidermis, together forming a 'cholesterol sulfate cycle' that potently regulates epidermal differentiation, barrier function and desquamation. In XLI, cholesterol sulfate levels my exceed 10% of total lipid mass (≈1% of total weight). Multiple cellular and biochemical processes contribute to the pathogenesis of the barrier abnormality and scaling phenotype in XLI. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. Guest Editors: Kenneth R. Feingold and Peter Elias.

Placental steroidogenesis in pregnant women with polycystic ovary syndrome

OBJECTIVE

To evaluate the placental activity of steroid sulfatase (STS), 3β-hydroxysteroid dehydrogenase type 1 (3β-HSD-1) and P450 aromatase (P450arom) in polycystic ovarian syndrome (PCOS) compared to normal pregnant women.

DESIGN

Twenty pregnant women with PCOS and 30 control pregnant women who delivered at term were studied. Samples of placental tissue and cord blood were obtained after delivery. A maternal blood sample was obtained during the 34th week of gestation. In placental tissue, the activities of STS, 3β-HSD-1 and P450arom were evaluated. In the blood samples, progesterone, DHEAS, DHEA, androstenedione, testosterone, estrone, estradiol and total estriol were determined.

RESULT

In placental tissue from women with PCOS, higher 3β-HSD-1 and lower P450 aromatase activities were observed compared to control women. Moreover, women with PCOS showed higher androstenedione and testosterone concentrations compared to normal pregnant women (p=0.016 and p=0.025, respectively). In cord blood, female newborns of women with PCOS exhibited lower androstenedione and higher estriol concentrations compared to daughters of control women (p=0.038; p=0.031, respectively).

CONCLUSION

These data suggest that placental tissue from women with PCOS shows changes in the activities of two important enzymes for steroid synthesis, higher 3β-HSD-1 and lower P450, which could increase androgen production during pregnancy.