DNA extraction; interpretation
Pertinent medical findings must accompany the test request form. A Clinical Questionnaire for Reveal SNP Microarray - Pediatric must be completed.
This test may also be performed on adults. When a child tested with this assay is found to have an abnormal array of unknown clinical significance that may be clarified through parental testing, there will be no charge associated with the follow-up parental testing that is based on the child's results. All other parental follow-up testing will be charged, including (but not limited to) autism susceptibility regions, known microdeletions/microduplications, autosomal recessive deletions/duplications, and large copy-number changes with likely pathogenic significance. The child's abnormal array results will indicate whether parental testing will be performed at no charge and will include the appropriate parental follow-up test number.
Whole blood or LabCorp buccal swab kit (buccal swab collection kit contains instructions for use of a buccal swab).
4 mL or LabCorp buccal swab kit
2 mL (neonatal) (Note: This volume does not allow for repeat testing.) or two buccal swabs
Green-top (heparin) tube (preferred), yellow-top (ACD) tube, or lavender-top (EDTA) tube or LabCorp buccal swab kit.
Maintain specimen at room temperature.
Causes for Rejection
Quantity not sufficient for analysis; wet buccal swab
Detects chromosomal imbalance that may be present in newborns or children with developmental delay/congenital anomalies/autism; genotyping in the array allows detection of uniparental disomy of autosomes, the presence of consanguinity, and the associated genomic location of recessive allele risk.
This assay does not detect balanced rearrangements and low-level mosaicism.
Whole genome SNP-based copy number microarray analysis targeting 2.695 million copy number and allele-specific genome sites
Positive evaluation criteria include: DNA copy gain/loss within known clinically significant gene region of 50 kb or greater. DNA copy number loss >200 kb or gain >500 kb outside known clinically significant regions with at least one OMIM annotated gene or within a region of clear clinical significance. UPD testing is recommended for patient results demonstrating a long contiguous region of homozygosity in a single chromosome >20 Mb interstitially or >10 Mb telomerically (15 and 8 Mb, respectively, for imprinted chromosomes). Contiguous homozygosity >10 Mb within multiple chromosomes suggests common descent. These regions of potential recessive allele risk are designated.
Shaikh TH. Oligonucleotide arrays for high-resolution analysis of copy number alteration in mental retardation/multiple congenital anomalies. Genet Med. 2007 Sep; 9(9):617-625.