The phenotype spectrum of X-linked ichthyosis identified by chromosomal microarray

Area of Science:

• Genetics
• Dermatology
• Genomic Medicine

Background:

• X-linked ichthyosis (XLI) is caused by Steroid sulfatase (STS) gene disruption.
• Chromosomal microarray (CMA) can incidentally detect STS deletions during genome-wide screening.
• CMA is typically used for noncutaneous congenital anomalies.

Purpose of the Study:

• To investigate the spectrum of skin features in patients with STS deletions identified by CMA.
• To compare these features with classic XLI cases from literature and clinical diagnosis.

Main Methods:

• Identified male patients with STS deletions from 23,172 CMA tests.
• Compared findings with a dermatology clinic cohort of biochemically confirmed XLI patients.
• Reviewed medical records, skin histopathology, photographs, and conducted a literature search.

Main Results:

• Patients diagnosed incidentally via CMA exhibited milder skin phenotypes (dryness/eczema).
• These patients did not present with the characteristic polygonal or "dirty" scale of XLI.
• Suggests STS deletions may present with less severe skin manifestations.

Conclusions:

• STS deletions can lead to a milder skin phenotype than typical XLI.
• Limitations include small sample size and limited clinical data.
• Further research is needed to fully understand the phenotypic variability.