Chromosome analysis, stimulated peripheral blood
Clinical indications
- Individuals and couples with infertility, multiple miscarriages
- Delayed puberty, ambiguous genitalia, amenorrhea
- Developmental delay/intellectual disability, dysmorphology, birth defects
- Clinical features suggestive of multiple congenital anomalies/aneuploidy syndrome, including Down syndrome, Trisomy 13 syndrome, and Trisomy 18 syndrome
- Family history of chromosomal abnormality
- Confirmation of prenatal diagnosis
What it detects
- Microscopic aberrations >5 Mb in size:
- Aneuploidy
- Translocations
- Deletions/duplications
- Inversions
- Polymorphic variants
Test Limitations
- Does not detect aberrations < 5 Mb
Specimen Requirements
- Volume: 5 ml of whole peripheral blood (minimum of 1 ml)
- Container: green top (sodium heparin)
- Transportation conditions: room temperature
Methodology
- PHA stimulated cell culture followed by G-banded chromosome analysis.
- 20 metaphase cells examined, with a minimum of 5 cells fully analyzed and 2 cells karyotyped.
- Additional 30 cells screened in case a non-clonal abnormality is identified or a sex chromosome mosaicism identified in fewer than 10 of the original 20 cells.
- The majority of cells analyzed at or above the 500-band level.