Multimodal Imaging of Pre-Descemet Corneal Dystrophy Associated With X-Linked Ichthyosis and Deletion of the STS Gene

Abstract

Purpose: To investigate the presence of pre-Descemet corneal dystrophy (PDCD) in association with X-linked ichthyosis (XLI) in an 11-year-old boy using multimodal imaging and genetic analysis. Methods: Corneal opacities were examined and imaged with slit-lamp biomicroscopy, anterior segment optical coherence tomography, noncontact specular microscopy, and in vivo confocal microscopy. Cytogenomic array analysis was performed using genomic DNA isolated from the patient. Results: Corneal opacities characteristic of PDCD located in the posterior corneal stroma just anterior to Descemet membrane were identified by slit-lamp biomicroscopy. A pre-Descemet hyper-reflective line, consistent with these opacities, was seen with anterior segment optical coherence tomography. Scheimpflug tomography revealed a bimodal peak light scattering. In vivo confocal microscopy findings were unremarkable. Copy number analysis identified a 4389 kbp hemizygous deletion on the X chromosome (chr. X: 6,540,898–8,167,604), resulting in the deletion of 4 genes, including the known locus of XLI, the STS gene. Conclusions: This report demonstrates that PDCD-associated XLI may present in children and that the diagnosis may be confirmed through multimodal imaging in conjunction with genetic analysis.

Prenatally detected six duplications at Xp22.33-p11.22: a case report

“…STS belongs to the sulfatase family and hydrolyses several 3β-hydroxysteroid sulphates, which serve as metabolic precursors for oestrogens, androgens, and cholesterol [ 10 ]. Large deletions/duplications of the STS gene are associated with X-linked ichthyosis ( XLI) and are inherited in a recessive manner on the X chromosome [ 11 ]. Several previous studies have proven that the STS gene in the Xp22.3 chromosome is associated with some inherited diseases, including Turner syndrome and Klinefelter syndrome [ 12 ].…”

Advanced Anterior Eye Segment Imaging for Ichthyosis

“…Dystrophy is characterized by the accumulation of polymorphic grey hyperreflective opacities located anterior to Descemet’s membrane and revealed by slit-lamp examination. In vivo confocal microscopy (IVCM) reveals enlarged hyperreflective keratocytes with extracellular deposits in the posterior corneal stroma [ 8 , 9 , 10 , 11 ].…”

“…In recent years, multimodal imaging in ophthalmology, combining topography, pachymetry, corneal biomechanics, and morphology data, has provided significant new insights into the diagnosis of ocular surface, corneal, and anterior eye segment diseases, especially in cases of rare congenital diseases, such as corneal dystrophies [ 8 , 21 , 22 ]. The experience gained based on corneal dystrophy analysis may be utilized in ichthyoses to provide comprehensive assessments in terms of topography, morphology, and cellular imaging.…”

“…The experience gained based on corneal dystrophy analysis may be utilized in ichthyoses to provide comprehensive assessments in terms of topography, morphology, and cellular imaging. To date, multimodal imaging has only been described for specific ichthyosis-related syndromes, such as PPCD [ 8 , 9 , 10 , 11 ]. Describing the morphological features of ichthyoses, including the character of abnormalities, anterior and posterior keratometry values, and the morphology of all corneal layers, using non-invasive imaging methods, would produce new valuable data in the context of the impact of ichthyoses on the corneal structure.…”

“…This technique is useful for several clinical conditions, including infectious keratitis, dry eye disease (DED), corneal dystrophies, and degenerations [ 26 , 27 ]. To date, the use of IVCM in ichthyoses was limited to PPCD in RXLI [ 8 , 9 , 10 , 11 ].…”