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Lab Dept:
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Anatomic Pathology
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Test Name:
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RETT SYNDROME (MECP2) SEQUENCING
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General Information
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Lab Order Codes:
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RSSA
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Synonyms:
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MECP2 Sequencing Analysis
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CPT Codes:
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81302 – MECP2 gene analysis; full sequence analysis
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Test Includes:
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DNA sequencing of MECP2 exons 1-4 in both directions using 96-capillary sequencer
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Logistics
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Test Indications:
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Rett syndrome is an X-linked neurodevelopmental disorder caused by mutations in the MECP2 gene which encodes the Methyl CpG Binding Protein 2 transcriptional repressor. Rett syndrome affects ~1 in 10,000 females with symptoms including loss of speech and purposeful hand use, microcephaly, seizures, ataxia, and stereotypic hand movements. MECP2 mutations manifest a broader spectrum of clinical phenotypes in female and rare male patients, with features overlapping with other mental retardation disorders. Mutations in the MECP2 coding region can be detected by sequence analysis in up to ~85% of Rett cases. Medical Genetics offers DNA sequencing analysis of MECP2 exons 1 through 4.
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Lab Testing Sections:
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Anatomic Pathology - Sendouts
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Referred to:
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Baylor College of Medicine-Medical Genetics Laboratories
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Phone Numbers:
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MIN Lab: 612-813-6280
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STP Lab: 651-220-6550
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Test Availability:
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Daily, 24 hours
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Turnaround Time:
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3 weeks
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Special Instructions:
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Please include completed Baylor Request Form and Consent Form.
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Specimen
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Specimen Type:
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Whole blood
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Container:
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Lavender top (EDTA) tube
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Draw Volume:
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3 - 5 mL Children/adults
3 mL Infants
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Processed Volume:
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Same as Draw Volume
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Collection:
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Routine venipuncture
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Special Processing:
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Lab Staff: Do Not centrifuge. Specimen should be kept in original collecton container. Ship the specimen FedEX Monday through Thursday only, ship at room temperatures.
Note: For specimens collected Friday – Sunday (or on a holiday), they should be held in Children’s Laboratories at refrigerated temperatures and shipped at room temperature on Monday (or the next business day Monday – Thursday).
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Patient Preparation:
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None
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Sample Rejection:
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Mislabeled or unlabeled specimens
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Interpretive
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Reference Range:
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No mutations detected
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Critical Values:
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N/A
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Limitations:
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Previously, testing laboratories had performed sequence analysis of the MECP2 coding region which was thought to consist of exons 2 through 4. Recently, rare mutations in MECP2 exon 1 have been reported in a few Rett patients. For patients who had previously tested negative by sequence analysis of exons 2 through 4, targeted sequencing analysis of MECP2 exon 1 can be requested through our laboratory. More significantly, testing may be considered for MECP2 gene deletions which have been identified in approximately 10% of Rett patients. (See MECP2 Deletion Analysis which is offered as a separate test).
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Methodology:
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PCR amplification, gel electrophoresis
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References:
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Baylor College of Medicine – Medical Genetics November 2010
(800) 411-4363 Fax (713) 798-2787
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Updates:
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2/11/2013: CPT update
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