DNA Analysis Laboratory

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