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 table below for all DNA tests performed by the DNA Analysis Laboratory.

Specimen Submission (Use form G-1B) (only required for non-newborn screening specimens)

Required Sections for DNA test requests:

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

Send specimens to:

Specimen Acquisition
Texas Department of State Health Services
Laboratory Services Section
Mail Code 1947
PO Box 149347
Austin, TX 78714-9347

For contract and other information, call (512) 776-7430

Hemoglobinopathies

Mutations for hemoglobin types S, C, E, D-Los Angeles, and O-Arab, and two beta-thalassemia point mutations are detected by polymerase chain reaction and restriction fragment length polymorphism. Partial sequencing of the β-Globin gene is used for identification of other mutations. Specimens from the newborn screening program that test positive for specific hemoglobinopathies are referred for confirmatory DNA testing. Fee-for-service testing is also available. Click for more information

Galactosemia

Common mutations/variants in the galactose-1-phosphate uridyl transferase (GALT) gene are identified by a tetra-primer amplification refractory mutation system-polymerase chain reaction. The mutation detection rate is estimated to be 70 percent in Caucasians but reduced in other ethnic groups. Specimens from the newborn screening program that test abnormal for GALT enzyme activity are referred for confirmatory DNA testing. Fee-for-service testing is also available. Click for more information

Cystic Fibrosis (CF)

Forty common mutations in the cystic fibrosis transmembrane conductance (CFTR) regulator gene are identified by multiplex polymerase chain reactions and fluorescent signal detection. The mutation detection rate is estimated to be 38.7-89.12 percent, depending on the patient's ethnicity. Selected specimens from the newborn screening program with an abnormal immunoreactive trypsinogen level are referred for DNA testing. Fee-for-service testing is also available. 

Medium Chain Acyl-CoA Dehydrogenase Deficiency (MCADD)

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

Severe Combined Immunodeficiency (SCID)

All specimens are screened to detect reduced presence or absence of T-cell receptor excision circle (TREC) by Real-Time polymerase chain reaction.

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