Early Infantile Epileptic Encephalopathy 4

Disorders

Early Infantile Epileptic Encephalopathy 4

Gene Name STXBP1
Clinical info Early infantile epileptic encephalopathy (EIEE) is a group of disorders characterized by severe epilepsy beginning in infancy attributed to mutations in more than 10 different genes.

STXBP1 is associated with EIEE type 4. Patients with STXBP1 mutations have been reported to have partial complex seizures, tonic-clonic seizures, severe to profound intellectual disability, hypotonia, tremor, hypsarrhythmia, spastic diplegia and spastic quadriplegia.  The age of onset for seizures ranges from 3 days to 9 months.  Since EIEE4 is inherited in an autosomal dominant manner, most mutations are expected to be de novo.
Indications Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutation within a family to allow for carrier testing and prenatal diagnosis.
Associated Tests

Mutations in the ARX and CDKL5 genes are also associated with forms of EIEE.  Sequencing of these genes is available through the Molecular Diagnostic Laboratory.

Specimen Requirements 5 to 10 ml of peripheral blood collected in an EDTA (lavender top) Vacutainer tube is preferred. The minimal blood needed for reliable DNA isolation is 3 ml.
Transport The specimen should be kept at room temperature and delivered via overnight shipping.  FedEx is preferred.  If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature.  Do not freeze the specimen.  Samples collected on Friday can be safely designated for Monday delivery.
Turnaround time 6 weeks
Prenatal testing Prenatal diagnosis is available if the familial mutation is known. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen.
CPT Codes Unknown mutation: 81406

Known mutation: 81404

Deletion/Duplication Analysis: 81229
Cost $1800 for sequencing

$350 for known mutation

$700 for deletion/duplication analysis

Prenatal diagnosis for known mutation is $1000.  Please contact the laboratory for more information.

Contact For further information contact This email address is being protected from spambots. You need JavaScript enabled to view it. , MS, Lab Counselor at 1-800-473-9411.

Molecular Diagnostic Lab

The Molecular Diagnostic Lab offers DNA analysis for many genetic disorders via gene sequencing, targeted mutation analysis, MLPA deletion/duplication testing, trinucleotide repeat analysis and next generation sequencing panels.

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