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

Congenital Ichthyosis: Current Approaches to Prenatal Diagnoses

INTRODUCTION

Congenital ichthyosis represents a wide spectrum of diseases. This article reviews prenatal testing for ichthyosis.

METHODS

We used pubmed.ncbi.nlm.nih.gov to search for 38 types of congenital ichthyosis combined with 17 words related to prenatal testing.

RESULTS

Search resulted in 408 publications covering 13 types of ichthyoses and four types of tests.

DISCUSSION

Biochemical testing is diagnostic in trichothiodystrophy, but nonspecific in X-linked ichthyosis and Refsum syndrome. Except in X-linked ichthyosis, biochemical testing requires invasive procedures to obtain fetal skin biopsy, amniocytes, or chorionic villus samples. It is superior to histological and cytological examination of fetal skin biopsy or amniocytes because keratinization occurs later in pregnancy and microscopy cannot differentiate between ichthyosis types. Imaging is more acceptable due to noninvasiveness and routine use, although ultrasonography is operator-dependent, nonspecific, and captures abnormalities at late stage. Molecular tests are described in at-risk pregnancies but testing of free fetal DNA was not described.

Placental steroid sulphatase deficiency: an approach to antenatal care and delivery

Placental steroid sulphatase deficiency (SSD) is an X-linked inborn error of metabolism. Congenital X-linked ichthyosis (XLI) is a genetic disorder of keratinisation caused by steroid sulphatase (STS) deficiency, which results in a scaling skin condition in male infants shortly after birth. It may be associated with failed induction of labor and prolonged labor leading to cesarean delivery due to 'cervical dystocia'. We present two cases of congenital ichthyosis. Thorough counselling of women with a previously affected pregnancy during the antenatal period should include discussion about mode of delivery and a critical review of the complexities of prenatal diagnosis in this condition. We propose a clinical management pathway to offer women with a previous pregnancy affected by this rare condition. SIMILAR CASES PUBLISHED: Less than 50 cases reported.

Hypoplastic thyroid, growth hormone deficiency, corneal opacities, cataract and hyperkeratotic skin disease: a possible new ichthyosis syndrome associated with endocrinopathies

A 56 year old man presented with ichthyosis vulgaris since early childhood, clinically characterised by fine scaling of the trunk and hyperkeratotic scales on the exterior surfaces of the upper and lower extremities. The patient also showed hypothyroidism due to hypoplastic thyroid, cataract, hypercholesterinemia with concommitant arcus cornealis and biliary concrements. Renal lithiasis caused by calcio-oxalate was additionally present. Endocrinological screening revealed growth hormone deficiency in the 1.55 m tall man-(secondary) osteoporosis was observed. The clinical symptomatology indicates that this case cannot be considered as a subtype of the inherited ichthyosis group, but suggests a new syndrome as a separate nosologic entity.