RETT SYNDROME
MECP2 Deletion Analysis
DNA ANALYSIS
Also see: Rett Syndrome - MECP2 Sequencing

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 (see MECP2 Sequencing Analysis). In addition, large MECP2 gene deletions have been identified in approximately 10% of Rett patients. Our laboratory offers Southern analysis to detect gene rearrangements involving MECP2 (exons 1 through 4) for patients with a documented negative MECP2 sequencing study.

Reasons for Referral:

Diagnostic testing
Prenatal testing for known familial mutation.

Testing Methodology:

Southern and densitometry analysis for gene rearrangements involving MECP2 exons 1-4.

Sensitivity:

Sequencing has an analytical sensitivity of ~99% for point mutations. Up to ~95% of classic Rett patients have small or large mutations in the MECP2 gene.

Specimen Requirements:

Blood: EDTA (purple-top) tubes: Adults: 14 cc; Child: 6 cc; Infant: 6 cc
Please contact the laboratory for specific requirements for prenatal testing.

Turnaround Time:

3 weeks

CPT Codes and Prices:

83891, 83892x2, 83894x4, 83896x2, 83897x2, 83912

References:

1. Amir R, et al. (1999) Nat. Genet. 23: 185-188.
2. Amir RE, Zoghbi HY. (2000) Am. J. Med. Genet. 97: 147-152.
3. Mnatzakanian GN, et al. (2004) Nat. Genet. 36: 339-342.
4. Laccone F, et al. (2004) Hum. Mutat. 23: 234-244.