Tay-Sachs disease, DNA analysis-13555

Test info

  
Tay-Sachs disease, DNA analysis
  
13555
  
LAB13555
  
TAYSACHDNA
  
Hexosaminidase A deficiency
  

Pre- and postnatal determination of Tay-Sachs disease carrier status; resolution of pseudodeficiency allele status.

Specimen

  
EDTA whole blood
  
  
7 mL
  
3 mL
  

Immediatley following collection, mix sample thoroughly by gently inverting 8 - 10, times to prevent clotting

  

Lavender (EDTA), 10mL

  
ACD whole blood
Amniotic fluid;Chorionic villus sample (CVS) (submission of maternal blood is required for fetal testing)
  

Yellow ACD (A or B)

 

Sterile vial/container

 

 

 

 

  
Amniotic fluid - 10 mL (minimum 5mL); CVS - 20 mg (minimum 10 mg)
  

Yellow ACD (A or B)

Sterile vial/container

  
  

Ambient

  
  • Frozen specimen
  • Hemolysis
  • Quantity not sufficient for analysis (QNS)
  • Improper container

Performance

  
LabCorp RTP (510404): R-LC
  
2 X / wk, or as needed
  
8 - 14 days
  

Polymerase chain reaction (PCR); primer extension; flow- sorted bead array analysis for five mutations and two pseudodeficiency alleles in the hexosaminidase A gene

Clinical and Interpretive info

  

An interpretive report will be provided

  

Tay-Sachs disease is an autosomal recessive lysosomal storage disorder that causes progressive neurological deterioration ranging in severity from forms with infantile onset to those with adult onset. If the individual tested by DNA analysis is not of Ashkenazi Jewish descent, carrier testing by enzyme analysis is strongly recommended. Couples who are both carriers have a one in four risk of having a child with Tay-Sachs disease. DNA test results should be combined with enzyme test results and clinical information for the most accurate interpretation. The mutations tested include: 1278insTATC, G269S, IVS9+1 G>A, 1421+1 G>C, 7.6 kb deletion. Pseudodeficiency alleles tested include: R247W and R249W.

NOTE: The pseudodeficiency mutation, R247W, accounts for 32% of enzyme-defined carriers in the non-Jewish population, while R249W accounts for 4% of pseudodeficiency among Ashkenazi Jews. These mutations affect the enzyme test, but do not affect in vivo function of beta-hexosaminidase A. Carriers of these mutations are not at increased risk to to have children with Tay-Sachs disease.

Billing

  
This test may require preauthorization from the insurance provider. Check the payer guidelines and, if needed, obtain the pre-authorization prior to sample collection.
  
81255
  
Yes
  
Result 32632-2
  

Medical necessity

Hospital clients submitting a request for this assay on an outpatient with Medicare should complete and submit a Molecular Medical billing request form along with the sample.

  • Complete and submit the form to notify us of the need for Allina Health Laboratory to bill insurance for Molecular testing performed
  • All information requested is required in order for your request to be completed

Molecular Medicare billing request

Tracking

  
04/11/2019
  
06/23/2023
  
04/11/2022