Fish Analysis, Miller-Dieker Syndrome, Isolated Lissencephaly and Subcortical Band Heterotopia

Cytogenetics Test Requisition Specimen Information Billing Information Contact Us CPT Codes     Print Page

FISH ANALYSIS, MILLER-DIEKER SYNDROME, ISOLATED LISSENCEPHALY and SUBCORTICAL BAND HETEROTOPIA

Chromosomal Locus: 17p13.3

Pseudonyms: PAFAH1B1-Associated Lissencephaly/Subcortical Band Heterotopia, 17-Linked Subcortical Band Heterotopia, Isolated 17-Linked Lissencephaly
 
TURNAROUND TIME: 7 to 10 days
 
 
TESTING METHODOLOGY: Fluorescence in situ hybridization
 
SPECIMEN REQUIREMENTS:
  • Collect: 3-5 mL peripheral blood in sodium heparin (green) for children and adults; 1-2 mL peripheral blood in sodium heparin (green) for newborns
  • Min. Collection: 1 mL for newborns; 2 mL for children and adults
  • Transport: peripheral blood in sodium heparin (green) at 20-25°C
  • Stability: Ambient: 24 hours; Refrigerated: 72 hours; Frozen: unacceptable
  • Unacceptable Conditions: Frozen or clotted specimens; specimens in anticoagulants other than sodium heparin.
A Cytogenetics Laboratory Test Requisition must accompany the specimen. Contact the Cytogenetics Laboratory at 918-502-1722 to obtain further information.
 
INTERPRETATIVE DATA:
 
Test Summary: Test can detect microdeletions of the LIS1 gene on chromosome 17. Miller-Dieker syndrome is associated with deletions that include both LIS1 and YWHAE in 17p13.3. Approximately 54% of patients with isolated lissencephaly have a deletion of LIS1 detectable by FISH. Mosaic deletions of LIS1 have been identified in patients with subcortical band heterotopia.
 
 
Methods: A dual-color FISH analysis performed on metaphase cells using a probe for the LIS1 gene in 17p13.3 and a chromosome 17 control probe; analysis of 10 metaphase cells and 20 interphase cells.
 
Indications for Use:
  • Patients suspected of having Miller-Dieker syndrome on the basis of clinical findings such as lissencephaly, seizures, developmental delay, and distinct facial features.
  • Patients with isolated lissencephaly
  • Patients with subcortical band heterotopia.
ADDITIONAL RESOURCES: