Use

This fluorescence in situ hybridization (FISH) assay screens for numerical chromosomal abnormalities associated with common prenatal aneuploidies, including trisomy 13, trisomy 18, trisomy 21 (Down syndrome), and sex chromosome abnormalities such as Turner syndrome, Klinefelter syndrome, and triploidy. It does not detect other chromosome aneuploidies, structural abnormalities, or low‑level mosaicism. A positive FISH result should be confirmed by chromosome analysis or supported by consistent clinical information before irreversible therapeutic decisions are made.