Fluorescence in situ Hybridization (FISH)
*performed by affiliate laboratory
5.0 mL (min. 3.0 mL) peripheral blood, sodium heparin
Protect from extreme temperature. Ship with cool pack (refrigerated). Ship on Saturday for Monday delivery only if sample is protected from extreme temperature.
Clotted specimen; Specimen exposed to extreme temperature; Anticoagulant or collection vessel toxic to cells; Insufficient number of cells; Specimen exposed to fixative
Presence or absence of the microdeletion
It is recommended that all FISH studies be done in conjunction with routine cytogenetic studies. If the FISH result is normal, a chromosome analysis allows identification of more complex abnormalities.
Wolf-Hirschhorn syndrome, causing deletion of the short arm of chromosome 4, affects approximately 1 in 50,000 births.