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Rett syndrome

Rett syndrome is a progressive, neuro-developmental disorder that affects approximately 1 in 10,000 females. Classic Rett syndrome is diagnosed based on a defined set of clinical criteria and characterized by apparently normal development in the first 6-18 months, followed by an arrest in development and subsequent regression in language and motor skills. Frequent symptoms include […]

Rett syndrome is a progressive, neuro-developmental disorder that affects approximately 1 in 10,000 females. Classic Rett syndrome is diagnosed based on a defined set of clinical criteria and characterized by apparently normal development in the first 6-18 months, followed by an arrest in development and subsequent regression in language and motor skills. Frequent symptoms include loss of speech and purposeful hand use, stereotypic hand movements, ataxia, microcephaly, and seizures. “Atypical” Rett syndrome can be milder or more severe than typical Rett syndrome and is diagnosed when some but not all clinical criteria for Rett syndrome are present. The milder form may include mental retardation, mild learning disablilities and/or autism. Mutations in the MECP2 gene have been found to cause Rett syndrome and “atypical” Rett syndrome in females. In males, MECP2 mutations are not as common and responsible for a broad spectrum of neurodevelopmental phenotypes, ranging from severe neonatal encephalopathy to a variety of neuropsychiatric features or mild mental retardation. Rarely, males with a progressive neurodevelopmental syndrome, including mental retardation, spasticity, speech and social problems, have been found to have a duplication or triplication of the MECP2 gene.

CDKL5 mutations have been associated with X-linked mental retardation and a broad spectrum of neurological symptoms that show broad overlap with atypical Rett syndrome and Angelman syndrome. The majority of patients are females. Most patients have a severe phenotype with early-onset encephalopathy and infantile spasms, global developmental delay and mental retardation, although cases with much milder symptoms have been reported.

Tests Available

EpiXpanded Panel

FORMS AND DOCUMENTS

TEST DETAILS

Clinical Utility:
  • Molecular confirmation of a clinical diagnosis
  • To assist with decisions about treatment and management of individuals with epilepsy
  • Testing of at-risk relatives for specific known variant(s) previously identified in an affected family member
  • Prenatal diagnosis for known familial pathogenic variant(s) in at-risk pregnancies
Lab Method:
Next-gen Sequencing

ORDERING

Test Code:
921
Turnaround Time:
6 weeks
Preferred Specimen:
2-5 mL Blood - Lavender Top Tube
Alternative Specimen:
Oral Rinse (30-40 mL), Dried Blood Spots

BILLING

CPT Codes:
81404x4, 81405x3, 81406x2, 81407x1, 81408x2
New York Approved:
Yes
ABN Required:
Yes
Billing Information:
View Neurology Billing Policy
* For price inquiries please email zebras@genedx.com

REFERENCES

  1. Pong et al. (2011) Pediatric Neurology 44 (5):317-27 (PMID: 21481738)
  2. Dyment et al. (2014) Clinical Genetics : (PMID: 25046240)
  3. Michaud et al. (2014) Human Molecular Genetics 23 (18):4846-58 (PMID: 24781210)
  4. Veeramah et al. (2013) Epilepsia 54 (7):1270-81 (PMID: 23647072)
  5. Allen et al. (2013) Nature 501 (7466):217-21 (PMID: 23934111)
  6. EuroEPINOMICS-RES et al. American Journal Of Human Genetics 95 (4):360-370 (PMID: 25262651)
  7. Lee et al. (2014) Jama 312 (18):1880-7 (PMID: 25326637)
  8. McKnight D, Retterer K, Juusola J, Brandt T, Richard G, and Suchy S, Genetic Testing Strategies for Patients with Epilepsy and Neurodevelopmental Disorders; (Abstract #562). Presented at the 2015 ACMG Annual Clinical Genetics Meeting, March 27, 2015, Salt Lake City, UT.

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