FISH, X‑Linked Ichthyosis Steroid Sulfatase Deficiency
Also known as: X-Linked Ichthyosis Syndrome
Use
This test uses fluorescent in situ hybridization (FISH) to detect deletions of the steroid sulfatase (STS) gene on the X chromosome, confirming a diagnosis of X‑linked ichthyosis (steroid sulfatase deficiency), a condition characterized by generalized, dark brown, polygonal scaling present from birth. Detection of STS deletions via FISH provides a rapid diagnostic tool, though deletions account for up to 90% of cases, and negative results may require further molecular testing to rule out point mutations or partial deletions.
Special Instructions
Not provided.
Limitations
FISH detects only deletions of the STS gene and may miss partial deletions or point mutations; a negative FISH result in the setting of high clinical suspicion should prompt further molecular genetic studies such as sequence analysis or deletion/duplication analysis.
Methodology
Chromosomal / Cytogenetics
Biomarkers
Unknown CNV
Copy Number Region
Result Turnaround Time
Not provided.
Related Documents
For more information, please review the documents below
Not provided.
Other tests from different labs that may be relevant