SCN1A Family-targeted Sequencing

Whole blood

7 mL

3 mL

Lavender-top (EDTA) tube or yellow-top (ACD) tube

This test is intended for testing of additional family members once a pathogenic variant or variant of uncertain significance has been identified in an affected individual. This option is available when the mutation is known and can be documented by the ordering physician. If the mutation cannot be documented, please order full gene sequencing.

This method does not reliably detect mosaic variants; large deletions; large duplications, inversions, or other rearrangements; deep intronic variants or variants outside of the regions targeted by this analysis. It may be affected by allele-dropout, it may not allow determination of the exact numbers of T/A or microsatellite repeats, and it does not allow any conclusion as to whether two heterozygous variants are present on the same or on different chromosome copies.

Results of this test are for investigational purposes only. The performance characteristics of this assay have been determined by LabCorp. The result should not be used as a diagnostic procedure without confirmation of the diagnosis by another medically established diagnostic product or procedure.

DNA sequencing

SCN1A-related seizure disorders encompass a spectrum of autosomal dominant disorders that ranges from simple febrile seizures (FS) and generalized epilepsy with febrile seizures plus (GEFS+) at the mild end to Dravet syndrome and intractable childhood epilepsy with generalized tonic-clonic seizures (ICE-GTC) at the severe end. Less commonly observed phenotypes include myoclonic-astatic epilepsy (MAE or Doose syndrome), Lennox-Gastaut syndrome (LGS), infantile spasms, and vaccine-related encephalopathy and seizures. Individuals with seizures on the more severe end of the spectrum most often carry a de novo pathogenic variant while individuals on the milder end of the spectrum often have an inherited pathogenic variant. In addition, the clinical presentation of family members carrying the same pathogenic SCN1A variant can vary. Consequently, testing combined with a detailed clinical history is recommended for the parents of any child with a SCN1A pathogenic variant or variant of uncertain significance.