DNA Analysis Laboratory

The DNA Analysis Laboratory performs first-tier testing for Severe Combined Immunodeficiency (SCID) as part of the Newborn Screening Panel. Second-tier testing is also offered for other disorders in support of the Newborn Screening Program, as well as other individuals, to determine carrier status or for mutational analysis. See the table below for all DNA tests performed by the DNA Analysis Laboratory.

Test Purpose Description Availability

Hemoglobinopathy

Detect variants causing hemoglobins S, C, E, D-Los Angeles, and O-Arab, and beta-thalassemia –29- and -88-point variants

Variants for hemoglobin types S, C, E, D-Los Angeles, and O-Arab, and two beta-thalassemia variants are detected by allelic discrimination real-time polymerase chain reaction. Partial sequencing of the β-Globin gene is used for the identification of other variants. Specimens from the Newborn Screening Program that test positive for specific hemoglobinopathies are referred for second-tier DNA testing. Fee-for-service testing is also available.

Available now

Galactosemia

Identify common variations in galactose-1-phosphate uridyl transferase

Common variants in the galactose-1-phosphate uridyl transferase (GALT) gene are identified by a tetra-primer amplification refractory mutation system-polymerase chain reaction. The variant detection rate is estimated to be 70 percent in Caucasians but reduced in other ethnic groups. Specimens from the Newborn Screening Program that test abnormally for GALT enzyme activity are referred for second-tier DNA testing. Fee-for-service testing is also available.

Available now

Cystic Fibrosis

Identify common variants in cystic fibrosis transmembrane conductance regulator gene

Sixty-four common variants in the cystic fibrosis transmembrane conductance (CFTR) regulator gene are identified by multiplex polymerase chain reactions and fluorescent signal detection. The variant detection rate is estimated to be 54.4 percent to 95.9 percent, depending on the patient's ethnicity. Selected specimens from the Newborn Screening Program with an abnormal immunoreactive trypsinogen level are referred for second-tier DNA testing. Fee-for-service testing is also available.

Available now

MCADD

Identify common variants in medium-chain acyl-CoA dehydrogenase gene

Four common variants in the medium-chain acyl-CoA dehydrogenase (MCAD) gene are identified by Real-Time polymerase chain reaction. The variant detection rate is estimated to be 86 percent of disease alleles in the Texas population. Specimens from the Newborn Screening Program with presumptive positive results for MCADD deficiency are referred for second-tier DNA testing. Fee-for-service testing is also available.

Available now

Severe Combined Immunodeficiency (SCID) 

 

Detect reduced presence or absence of T-cell receptor excision circle (TREC) 

All specimens are screened to detect reduced presence or absence of T-cell receptor excision circle (TREC) by Real-Time polymerase chain reaction. Fee-for-service testing for SCID is not available. 

Available only as part of NBS panel

VLCAD

Identify variants in very long-chain acyl-CoA dehydrogenase gene

Variants in the ACADVL gene coding for very long-chain acyl-CoA dehydrogenase (VLCAD) are identified by Sanger sequencing.  Of the known variants in this gene, approximately 95% can be detected using this methodology.  Specimens from the Newborn Screening Program with presumptive positive results for VLCAD deficiency are referred for second-tier DNA testing.  Fee-for-service testing is also available.

Available now

Specimen Submission to the DNA Analysis Laboratory 

All non-newborn screening specimens must be accompanied by a completed G-1B Form (PDF 218kb) when submitted for testing.

Required Sections of the G-1B form for DNA test requests

  • Submitter Information
  • Patient Information
  • Payer Source
  • DNA Analysis—test(s) requested

Specimen Shipping information

For Overnight/Priority Shipping (UPS, FedEx, etc.):

Texas Department of State Health Services
Laboratory Services Section, MC 1947
1100 W. 49th Street
Austin, TX 78756-3199

For regular mail:

Texas Department of State Health Services
Laboratory Services Section, MC 1947
PO Box 149341
Austin, TX 78714-9341

Result Reports

 

  • Galactosemia, MCADD, hemoglobinopathy common variants, and Cystic Fibrosis DNA results are available within 4-8 days after receipt of the specimen.

  • Hemoglobinopathy sequencing and VLCAD sequencing results are available within 7-18 days after receipt of the specimen.

  • Severe Combined Immunodeficiency (SCID) testing is completed as part of the Newborn Screening Panel and results are available within 4 to 8 days after receipt of the specimen

  • Healthcare providers may contact Laboratory Reporting for result reports, Monday through Friday, 8 am -5 pm by:

    • Faxing requests to 512-776-7533 or

    • Call 1-888-963-7111 ext. 7578 or for local calls 512-776-7578.