Saethre-Chotzen Syndrome (TWIST) Sequencing and MLPA

Disorder Saethre-Chotzen
Gene Name TWIST
Clinical info Saethre-Chotzen Syndrome is one of the most common autosomal dominant disorders of craniosynostosis, affecting approximately 1/2000 newborn infants. It is characterized by craniofacial and limb anomalies. Mutations in the TWIST gene, which maps to chromosome 7p21-p22 are found in a majority of individuals with Saethre-Chotzen syndrome. Nonsense, missense, insertion, and deletion mutations of the TWIST gene have been found in studies of patients with Saethre-Chotzen syndrome.
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 Deletion/duplication analysis for TWIST via multiplex ligation-dependent probe amplification (MLPA) is also available upon request.
Detection Sequencing of the gene will detect mutations in >50% of individuals with Saethre-Chotzen syndrome.
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 Sequencing: 2 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: 81404

Known mutation: 81404

MLPA: 881406

Cost $500 for sequencing
$350 for known mutation
$500 for MLPA deletion/duplication analysis
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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