Test Code: 1127

Epilepsy and Seizure Disorders: Deletion/Duplication Panel
Test Code: 1127
Turnaround time: 3 weeks

CONDITION DESCRIPTION

Epilepsy is defined as a disorder in which an individual has recurrent, unprovoked seizures. It has a prevalence of about 5-10 per 1000 people. While the causes of epilepsy are diverse, a significant proportion are considered to be genetic in origin. Epilepsy can occur as part of a clinical spectrum that is associated with a particular genetic syndrome, such as Mowat Wilson syndrome, Dravet syndrome, and “chromosomal” epilepsies. Common “chromosomal” epilepsies include 1p36 deletion syndrome, Wolf-Hirschhorn syndrome, Angelman syndrome, Miller-Dieker syndrome, 15q inversion- duplication, Down syndrome and ring chromosome 14 and 20. In addition, epilepsy can occur as an isolated finding, 40% of which are believed to be due to genetic causes. Approximately 2% of the genetic causes of isolated epilepsy are due to monogenetic causes while the rest are thought to be due to multifactorial genetic and environmental causes. Of the monogenetic genes identified, the majority code for ion channel subunits and neurotransmitter receptors.

The Epilepsy and Seizure Disorders Panel is comprised of a next generation sequencing (NGS) for syndromic and non-syndromic causes of seizures. It is recommended that individuals with seizures have a chromosomal microarray as a first tier test. Please read further about CEN4GEN’s CGH and SNP array tests (Test code: 4159 and 6798).

References:

  • Michelucci et al., (2012), Curr Neurol Neurosci Rep, 12:445-455.
  • Nicita et al., (2012), Seizure, 21:3-11.
  • Pal et al., (2010), Nat Rev Neurol, 6:445-453.
  • Pandolfo, (2011), Semin Neurol, 31:506-518.
  • Poduri and Lowenstein, (2011), Curr Opin Genet Dev, 21:325-332.

GENES

ABAT, ADSL, ALDH7A1, ARHGEF9, ARX, ASPM, ATP1A2, ATP6AP2, BCKDK, CACNA1A, CACNB4, CASK, CASR, CDKL5, CENPJ, CHRNA2, CHRNA4, CHRNB2, CLN3, CLN5, CLN6, CLN8, CNTNAP2, CPA6, CSTB, CTSD, DCX, DNAJC5, EFHC1, EMX2, EPM2A, FLNA, FOLR1, FOXG1, GABRA1, GABRG2, GAMT, GATM, GOSR2, GPR56, GPR98, GRIN2A, HCN1, HCN4, KCNA1, KCNJ10, KCNJ11, KCNMA1, KCNQ2, KCNQ3, KCNT1, KCTD7, LGI1, LIAS, MAGI2, MBD5, MCPH1, MECP2, MEF2C, MFSD8, MTHFR, NDE1, NDUFA1, NHLRC1, NRXN1, OPHN1, PAFAH1B1, PCDH19, PHF6, PLCB1, PNKP, PNPO, POLG, PPT1, PRICKLE1, PRICKLE2, RELN, SCARB2, SCN1A, SCN1B, SCN2A, SCN3A, SCN8A, SCN9A, SHH, SIX3, SLC19A3, SLC25A19, SLC25A22, SLC2A1, SLC9A6, SPTAN1, SRPX2, ST3GAL3, ST3GAL5, STIL, STXBP1, SYN1, TBC1D24, TCF4, TPP1, TSC1, TSC2, TSEN54, UBE3A, WDR62, ZEB2

INDICATIONS
This test is indicated for:

  • Individuals with epilepsy.

METHODOLOGY

Deletion/Duplication Analysis: DNA isolated from peripheral blood is hybridized to a gene-targeted CGH array to detect deletions and duplications. The targeted CGH array has overlapping probes that cover the entire genomic region.

Please note that a “backbone” of probes across the entire genome are included on the array for analytical and quality control purposes. Rarely, off- target copy number variants causative of disease may be identified that may or may not be related to the patient’s phenotype. Only known pathogenic off-target copy number variants will be reported. Off-target copy number variants of unknown clinical significance will not be reported.

DETECTION

Deletion/Duplication Analysis: Detection is limited to duplications and deletions. The CGH array will not detect point or intronic mutations. Results of molecular analysis must be interpreted in the context of the patient’s clinical and/or biochemical phenotype.

SPECIMEN REQUIREMENTS

Submit only 1 of the following specimen types
Type: Whole Blood

Specimen Requirements: In EDTA (purple top) tube: Infants (2 years): 3-5 ml
Older Children & Adults: 5-10 ml.

Specimen Collection and Shipping: Ship sample at room temperature with overnight delivery.

Type: Isolated DNA
Specimen Requirements: In microtainer: 10 μg
Isolation using the QiagenTM Puregene kit for DNA extraction is recommended.

Specimen Collection and Shipping: Refrigerate until time of shipment in 100 ng/ul of TE buffer. Ship sample at room temperature with overnight delivery.

RELATED TESTS

  • CEN4GEN’s CGH and SNP array tests (Test code: 4159 and 6798).
  • Custom diagnostic mutation analysis (test code: 6875) is available to family members if mutations are identified by targeted mutation testing or sequencing analysis.
  • Epilepsy and Seizure Disorders: Sequencing Panel.