| Angelman syndrome, Deletion 15q11.2, D15S10/UBE3A, FISH, for Genetic Diagnosis |
| WSLH Department: | Cytogenetics |
| WSLH Test Code: | 871F25 |
| Includes: | FISH analysis of 10 cells for deletion of the D15S10/UBE3A loci in 15q11.2 |
| Methodology: | **(CPT Codes: 88271, 88273)** Fluorescence in situ hybridization performed on metaphase cells using DNA probes (LSI Prader-Willi/Angelman Region D15S10; Vysis, Inc) specific for 15q11.2 (D15S10/UBE3A), simultaneously with a probe for 15p11.2 (D15Z1) in the short arm of chromosome 15 and a probe for 15q22 (PML) as controls. |
| Availability: | Monday-Friday 7:45 AM - 4:30 PM, Saturday 7:45 AM - 12:00 PM |
| Turn-around Time: | Approximately 10-14 days. (Reports are issued Monday-Friday 7:45 AM - 4:30 PM) |
| Recommended Uses: | Detection of deletion 15q11.2 associated with Angelman syndrome; phenotypic features include seizures, developmental delay, happy personality, little speech development, microcephaly. |
| Contraindications: | |
| Specimen Requirements: | 1-2 ml whole blood collected in sodium heparin vacuum type tube |
| Collection Kit/Container: | |
| Patient Preparation: | |
| Collection Instructions: | Draw blood using aseptic techniques into a sterile sodium heparin vacuum type tube. Invert tube to mix. If using larger tubes, draw to full volume to avoid over-treatment with heparin. |
| Specimen Handling and Transport: | Store and transport specimens at room temperature (may transport with coolant during hot, >85 degrees, weather). Specimens must be received by the laboratory within 24 hours of collection. |
| Unacceptable Conditions: | Blood that is collected in EDTA, sodium citrate, or other anti-coagulants is not acceptable. Blood that is clotted or hemolyzed is not acceptable. Blood must not be frozen. Plasma and serum are not acceptable. |
| Requisition Form: | Cytogenetics Lab Genetic Diagnosis Form #131 |
| Required Information: | Laboratory regulations require the following minimum information to be provided on the requisition form for a specimen to be accepted for testing: Patient name or unique identifier; date and time of collection, patient date of birth and sex, specimen type/site of collection, test request(s), reason for referral, clinician name and UPIN/NPI, and address for reporting results. Please be certain that name/identifier on the form matches that on the specimen label. |
| Results include: | Deletion 15q11.2 detected/not detected. Karyotype written using International System for Human Cytogenetic Nomenclature (ISCN) 2013 and interpretation of results. |
| Limitations: | Very small deletions, point mutations, uniparental disomy, and imprinting abnormalities are not detected by this assay. Negative FISH results do not rule out a diagnosis of Angelman syndrome. |
| Additional Tests Recommended: | Methylation specific PCR is recommended as the primary test for Angelman syndrome with FISH used to follow-up abnormal results to differentiate between deletion and uniparental disomy/imprinting abnormalities. Blood chromosome analysis is recommended to look for other causes of the abnormal phenotype. The FISH analysis may be performed as an independent test if chromosome analysis and/or MSPCR was performed previously. |
| Additional Comments: | If FISH assay is not performed in conjunction with chromosome analysis there is an additional charge for processing the specimen. |
| Additional Tests Performed: | |
