Test name: Combination Testing - Next Generation Sequencing (NGS) / Microarray
Indications for Combination Testing:
- Developmental delay(DD) / Intellectual disability (ID)
- Autism spectrum (ASD) and other Neurodevelopmental disorders
- Dysmorphic features
- Congenital anomalies
- Seizure disorders
- Neuromuscular disorders
- Imprinting-associated disorders, such as: Angelman syndrome (AS) and Prader-Willi syndrome (PWS)
- Suspected consanguinity
Combination Test Information:
- Combination testing combines our Autism/Intellectual Disability/Multiple Anomalies Next Generation Sequencing Panel AND our High Density SNP Microarray to provide your patients with our laboratory’s comprehensive assessment for common genetic causes of autism, intellectual disabilities, and multiple congenital anomalies.
- Our Combination Test is designed to be most helpful when a patient has findings suspicious of multiple potential genetic causes (microdeletions, microduplications, isodisomy, single gene conditions, etc.), generally the result of clinical ambiguity due to marked phenotypic overlap between various syndromes or numerous genetic causes for a single disorder.
- Ordering our Combination Test, rather than ordering the component tests sequentially, shortens the turnaround time for test results.
- Combination testing requires a single sample submission, ideal for difficult to draw patients.
- Both Next Generation Sequencing and SNP Microarray technologies provide cost-effective advantages over traditional testing methods such as Sanger sequencing, previous microarrays, and FISH testing.
- Combination testing is NOT whole exome sequencing or whole genome sequencing and does not detect small partial or whole gene deletions and duplications, balanced chromosome rearrangements, or low level mosaicism. The test will only identify single gene mutations in the genes included on the Autism/Intellectual Disability/Multiple Anomalies Next Generation Sequencing Panel.
- For more detailed information regarding the components of the Combination Test, please see the test’s respective webpages, Autism/Intellectual Disability/Multiple Anomalies Next Generation Sequencing Panel and High Density SNP Microarray.
- Our Combination Test will not identify small partial or whole gene deletions and duplications. For some genes, deletion and duplication analysis by an additional testing method, such as Multiple Ligation Probe Analysis (MLPA), may be indicated.
- For some indications, additional genetic testing may be appropriate. For example, if an imprinting disorder, such as Angelman syndrome, is suspected, methylation analysis may be indicated. Recommendations for additional testing differ based on the disorder suspected.
- If trisomy 13, 18, or 21 (Down syndrome) is suspected, chromosome analysis is recommended as the first-tier test.
- Depending on the clinical presentation of a patient, a disease specific Next Generation Sequencing panel may be most appropriate.
For questions regarding the usefulness of complementary testing for your patient, please call our laboratory at 402-559-5070 and ask to speak with a laboratory genetic counselor.
Specimen Requirements: Test kits are available – please contact the laboratory
- Blood: One 3-5 ml EDTA (purple top) tube
- For patients who have not previously been tested on NGS: Autism/ID/MA Panel GeneList1
- NGS: Autism/ID/MA Expanded Panel: 81302, 81321, and 81405(x3)
- High Density SNP Array: 81229 and 88230
Pricing: Contact the laboratory billing staff for current costs
Required Forms: Postnatal Test Request Form
Turn-around time: Results are typically available in 6-10 weeks
- ARTICLE: Chromosomal Microarray Is a First-Tier Clinical Diagnostic Test for Individuals with Developmental Disabilities or Congenital Anomalies. Am J Hum Gen 2010.
Step-by-step ordering instructions:
1) Access the postnatal test request form on the Human Genetics Laboratory website.
2) Complete the 2-page form. Under TEST SELECTION, mark the box next to the Combination Testing: NGS / Microarray to order tests simultaneously.
3) When ordering tiered testing, such as one test at a time, under SPECIAL TEST INSTRUCTIONS, indicate the order in which you would like the tests performed. For example, “Please complete microarray first. If negative, reflex to Next Gen Sequencing.”
4) Provide any clinical information that may be important for interpretation.
5) Obtain insurance pre-authorization when necessary; forms available.
6) Following HGL shipping & handling requirements, send completed test request form and specimen at room temperature within 24 hours of collection.