In situ hybridization on interphase cells and on chromosomal spreads with fluorochrome-labeled DNA probes (FISH) has in recent years expanded the diagnostic potential of cytogenetics to the recognition of cryptic chromosomal rearrangements or microdeletions that cannot be resolved with traditional microscopic observation.

The use of specific probes for chromosome regions involved in the main cytogenetic pathologies (Down syndromes; Edwards; Patau; Turner etc.) allows a rapid diagnosis in 24-48h from the collection of fetal cells.

Molecular cytogenetic analyzes using the FISH technique:

Numerical diagnosis of trisomy 21,13,18
Diagnosis of numerical anomalies of sex chromosomes X, Y
Cytogenetic diagnosis of microdeletion syndromes (Angelman / Prader-Willi / Williams, Wolf-Hirschhorn, Di George)
Study of the chromosomal structure in sperm cells (Probes 13,18,21 XeY)