Indications for Assure SNP Microarray Analysis
- Abnormal fetal ultrasound findings with a normal karyotype
- De novo apparently balanced chromosomal rearrangement
- Identification of marker chromosome
- Desire for additional information not provided by routine karyotyping
- Abnormal Ultrasound
- Family history of a chromosome abnormality
- Abnormal NIPT
- No growth for a POC sample
Specimen Requirements
Prenatal: 30 ml of amniotic fluid or 20 mg of chorionic villi tissue if fetal microarray analysis is requested on direct amniotic fluid or chorionic villi for a quicker turnaround time. 20 ml of amniotic fluid or 10 mg of chorionic villi tissue if microarray analysis is to be performed on cultured cells. 10mg of POC tissue (Fetal/villi).
Specimen Container
- Amniotic fluid: Sterile 15 ml screw-top container
- CVS: Sterile 15 ml screw cap containing sterile transport medium
- POC: Sterile container containing sterile transport medium
- Cultured Cells: 2 T25 flasks
All specimens must be labeled with the patient’s name, Date of birth and include a completed test requisition.
Methodology
SNP (single nucleotide polymorphism) microarray analysis utilizing more than 2.6 million copy and allele specific genomic sites. SNP analysis can detect copy neutral changes including uniparental disomy (UPD) and areas of homozygosity suggestive of consanguinity. Abnormal results are confirmed with Fluorescence In Situ Hybridization (FISH analysis).
Transport Temperature
Room temperature (DO NOT refrigerate, freeze, or centrifuge).
Causes for Rejection
- Amniotic fluid: Frozen specimen, excessive amounts of blood, inappropriate container
- CVS: Frozen specimen, absence of fetal tissue, inappropriate transport medium.
- POC: Frozen specimen, absence of fetal tissue, inappropriate transport medium
- Cultured cells: Frozen specimen, contamination
- Delay in transport >72 hours.
Turnaround Time
- Direct: amnio, CVS or POC 7 days
- Cultured cells: 7 days (additional time required for culturing is 10-14 days)