Table 1.

Molecular technology applications in Wisconsin routine newborn screening.

Molecular Application	Example Condition	Molecular Marker	Technology
First-tier markers	Severe combined immunodeficiency	T-cell receptor excision circles	Real-time polymerase chain reaction (PCR)
	Spinal muscular atrophy	Homozygous SMN1 exon 7 deletion	Real-time PCR
Second-tier markers	Cystic fibrosis	CFTR variants	Next generation sequencing
Supplemental “just-in-time” 1 information	Galactosemia	GALT c.563A>G, c.404C>T, and c.940A>G	Tetra-primer amplification refractory mutation system (Tetra-primer ARMS)–PCR
	Maple syrup urine disease	BCKDHA c.1325 T>A	Tetra-primer ARMS–PCR
	Sickle cell disease	HBB c.20 A>T	Sanger sequencing
	Pompe disease	GAA coding region and intron-exon junctions	Sanger sequencing
	Spinal muscular atrophy	SMN2 copy number	Droplet digital PCR

¹ Screening positive determination is based on the first-tier result, and “just-in-time” gene variant information is intended to help clinicians better interpret the first-tier testing results and be better prepared for their initial communication and discussion with families regarding newborn screening positive results.