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Labcorp # 511277 MECP2 Seq
Test Code2511277
Alias/See Also
• Rett Syndrome
CPT Codes
81302
Preferred Specimen
Whole blood, amniotic fluid, chorionic villus sample (CVS) (Submission of maternal blood is required for fetal testing.) or LabCorp buccal swab kit (The buccal swab collection kit contains instructions for use of a buccal swab.)
Minimum Volume
3 mL whole blood, two buccal swabs, 5 mL amniotic fluid, or 10 mg CVS
Instructions
A completed screening questionnaire must accompany specimens. Call 800-345-4363 to request forms, or photocopy the form Clinical Questionnaire for MECP2-related Disorders.
Transport Container
Lavender-top (EDTA) tube, yellow-top (ACD) tube, sterile plastic conical tube or two confluent T25 flasks for fetal testing, or LabCorp buccal swab kit
Specimen Stability
Maintain specimen at room temperature or refrigerated at 4°C.
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Frozen specimen; hemolysis; quantity not sufficient for analysis; improper container; wet buccal swab; one buccal swab
Methodology
DNA Sequencing
Limitations
This test does not detect variants in any other gene, nor does it detect genomic deletions or promoter or deep-intron variants. Molecular-based testing is highly accurate, but as in any laboratory test, rare diagnostic errors may occur
Clinical Significance
"Detects mutations in the gene for methyl-CpG-binding protein 2 (MECP2), which causes Rett syndrome, a severe neurological disorder leading to regression of developmental behaviors and expressive language skills. There are some suspected cases in males, but Rett syndrome primarily affects females. It is the second most common cause of mental retardation in females (frequency: 1:15,000 to 1:8,500 births). The risk of development of Rett syndrome seems to be equal among different ethnic groups.
Mutations in the gene for methyl-CpG-binding protein 2 (MECP2) are the most common cause of Rett syndrome. The MECP2 protein is one of the many components involved with the regulation of gene expression. Rett syndrome is considered to be the first syndrome identified directly related to mutations in a gene controlling gene expression.
The MECP2 gene is located on the X chromosome. Currently, the criterion for Rett syndrome diagnosis is completely clinical. A group of standardized clinical benchmarks has been used to identify Rett syndrome and to distinguish relative subsets within the Rett population. The most clinically defined group is referred to as classic Rett. Of these, the majority (80%) have MECP2 gene mutations. Although 12 mutations account for 73% of mutation-positive cases, nearly 300 disease-causing mutations have been identified.
"
Mutations in the gene for methyl-CpG-binding protein 2 (MECP2) are the most common cause of Rett syndrome. The MECP2 protein is one of the many components involved with the regulation of gene expression. Rett syndrome is considered to be the first syndrome identified directly related to mutations in a gene controlling gene expression.
The MECP2 gene is located on the X chromosome. Currently, the criterion for Rett syndrome diagnosis is completely clinical. A group of standardized clinical benchmarks has been used to identify Rett syndrome and to distinguish relative subsets within the Rett population. The most clinically defined group is referred to as classic Rett. Of these, the majority (80%) have MECP2 gene mutations. Although 12 mutations account for 73% of mutation-positive cases, nearly 300 disease-causing mutations have been identified.
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