MECP2 Related Disorders

Test name:  MECP2 Gene Testing
Also known as: MECP2-Related Disorders: Classic Rett Syndrome, Atypical Rett Syndrome, MECP2-Related Severe Neonatal Encephalopathy, PPM-X Syndrome, MECP2 Microduplication Syndrome

Indications:

• Clinical features of MECP2-related disorders including classic Rett Syndrome, atypical Rett syndrome, MECP2-related severe neonatal encephalopathy, or PPM-X syndrome
  • Classic Rett syndrome is a progressive neurodevelopmental disorder seen most often in females which is associated with normal developmental until approximately 6-18 months when regression in skills involving language and motor are seen following a later long-term stabilizing of skills. Common findings include specific stereotypical movements of the hands, seizures/tremors, acquired microcephaly, autistic features, apnea/hyperpnea, and/or certain behaviors.
  • Atypical Rett syndrome can be seen in individuals with clinical diagnosis of Angelman syndrome but no molecular confirmation, individuals with both spasticity/tremor and intellectual disability, females with mild learning concerns in females, and, rarely, females with an autism diagnosis only. Regression may occur after a few years of life with milder symptoms
  • MECP2-related severe neonatal encephalopathy is seen most often in affected males and often results in death before age 2.
  • PPM-X syndrome is associated with X-linked intellectual disability that may range from mild and non-progressive to severe intellectual disability in males with additional findings of manic depressive psychosis, pyramidal signs, parkinsonian features, and macro-orchidism.
  • MECP2 microduplication syndrome can be associated with hypotonia in the infant, severe intellectual disability, lack of speech, seizures, and/or respiratory infections.

• Prenatal and postnatal testing for at risk relative of and individual with a previously identified aberration in MECP2.

Test Information: Testing typically begins for a proband with MECP2 sequencing, and if sequencing is negative, then deletion/duplication analysis is recommended. However, if MECP2 microduplication syndrome is suspected, then testing would begin with MECP2 deletion/duplication analysis and would be followed by MECP2 sequencing, if requested. 

Additional tests available on postnatal samples (refer to additional pages for details):
          Single gene testing – refer to Test Catalog for tests offered at HGL
          Coming soon: Next Generation Sequencing (includes a Rett/Atypical Rett/Angelman subpanel)

Specimen requirements:

• Adult: one 3-5 ml whole blood EDTA (purple top)tube
• Newborn: one 3-5 ml whole blood EDTA (purple top) tube (minimum 1 ml)

CPT codes:

• MECP2 gene sequencing: 83894, 83896(x11), 83898(x8), 83904(x16)*
• MLPA: 83896(x13), 83900, 83901(x11), 83904*
• Familial Mutation Analysis:  Contact the laboratory billing staff for current codes 

*Unless using stored DNA from a prior sample, the following DNA Extraction codes (83891, 83894, 83907, 84311) will also apply once for molecular testing.

Pricing: Contact the laboratory billing staff for current costs

Shipping & Handling

Required forms: Postnatal Test Request Form

Turn-around time (times are estimates and may change with volume):

• MECP2 sequencing: 4 weeks
• MLPA: 4 weeks
• Familial Mutation Analysis:  2 weeks

Additional links: GeneReviews

 Revised 7-11-12