What Can Be Learned From This Test
Tier 1 testing is performed by sequencing the entire coding region of MECP2. This will detect point mutations, small deletions and small insertions. Reflexive testing for a partial or whole gene deletion by fragment analysis can be carried out; please note on submission form if this tiered approach is being requested.
A negative test result does not rule out a diagnosis of Rett syndrome. Sequencing alone will detect mutations in about 80% of individuals with classic Rett syndrome and in about 40% of individuals with atypical Rett syndrome. Deletion/duplication testing increases the detection rates to about 88% and 43%, respectively.
Draw 2ml–4ml of blood in EDTA/purple-top tube (minimum of 1ml–2ml for infants).
Turnaround time: 10-14 business days per tier
CPT Codes and Cost
Tier 1: Full Gene Sequencing
Tier 2: Dosage
Known Variant Testing