Prenatal diagnosis for placental steroid salfatase deficiency with fluorescence in situ hybridization: A case of X‐linked ichthyosis

Abstract

X-linked ichthyosis (XLI) is a relatively common genetic disorder that occurs in about one in every 2000-6000 male births. Clinically, XLI is characterized by a generalized scaling of the skin, with large, polygonal, dark brown scale, and more prominent on the extensor aspects of the limbs. It is known that an undetectable maternal serum, unconjugated estriol, associated with placental steroid sulfatase (STS) deficiency, may be the cause of cause of XLI. In most case, STS deficiency is caused by a complete or partial deletion of the STS gene mapped on chromosome Xp22.3. We describe here the prenatal detection of a male fetus affected with STS deficiency as a result of an undetectable unconjugated estriol in the second-trimester maternal serum screening. Microdeletion of the STS gene was confirmed by fluorescence in situ hybridization analysis of cultured amniotic fluid.

Topical Tazarotene 0.05% versus Glycolic Acid 70% Treatment in X-linked Ichthyosis due to Extensive Deletion of the STS Gene

“…The presence of exon 1 and exon 14 of the Kallman gene in our patient ruled out a contiguous gene syndrome. Prenatal molecular diagnosis recently demonstrated microdeletion of the STS gene by fluorescence in situ hybridization analysis of cultured amniotic fluid in a case of XLI (12).…”

Prenatal diagnosis of genodermatoses: current scope and future capabilities

“…Although it is routinely indicated for the screening of neural tube defects, trisomy 21, and trisomy 18, maternal serum screening during the second trimester of pregnancy can also be useful for the identification of XLI, a disorder that affects approximately one in 4000 male fetuses. 43 Maternal serum screening is available either as a triple screen, which includes alpha-fetoprotein, human gonadotropin, and unconjugated estriol (Ue3), or as a quad screen, which includes the hormone inhibin A in addition to the above. Isolated low levels of maternal serum Ue3 can be found in several conditions, including intrauterine fetal death, congenital adrenocortical hypoplasia, and Smith-Lemli-Opitz syndrome (OMIM #270400), but steroid sulfatase (STS) deficiency is the most likely cause.…”

“…Isolated low levels of maternal serum Ue3 can be found in several conditions, including intrauterine fetal death, congenital adrenocortical hypoplasia, and Smith-Lemli-Opitz syndrome (OMIM #270400), but steroid sulfatase (STS) deficiency is the most likely cause. [43][44][45][46] STS deficiency, the molecular basis of XLI, is due to a complete deletion of the STS gene is 90% of families. 44 In 10% of the cases of STS deficiency, a contiguous gene deletion syndrome may result in the association of Kallmann syndrome (OMIM #308700) and chondrodysplasia punctata (OMIM #302950).…”

“…Although it is routinely indicated for the screening of neural tube defects, trisomy 21, and trisomy 18, maternal serum screening during the second trimester of pregnancy can also be useful for the identification of XLI, a disorder that affects approximately one in 4000 male fetuses 43 . Maternal serum screening is available either as a triple screen, which includes alpha‐fetoprotein, human gonadotropin, and unconjugated estriol (Ue3), or as a quad screen, which includes the hormone inhibin A in addition to the above.…”

“…Maternal serum screening is available either as a triple screen, which includes alpha‐fetoprotein, human gonadotropin, and unconjugated estriol (Ue3), or as a quad screen, which includes the hormone inhibin A in addition to the above. Isolated low levels of maternal serum Ue3 can be found in several conditions, including intrauterine fetal death, congenital adrenocortical hypoplasia, and Smith‐Lemli‐Opitz syndrome (OMIM #270400), but steroid sulfatase (STS) deficiency is the most likely cause 43–46 . STS deficiency, the molecular basis of XLI, is due to a complete deletion of the STS gene is 90% of families 44 .…”