Congenital Nongoitrous Hypothyroidism

Gene: PAX8

Protein: paired box protein Pax-8

Clinical Characteristics

  • Thyroid dysgenesis: agenesis, hypoplasia or ectopia
  • Mild to severe hypothyroidism:
    • Elevated TSH
    • Low to normal total and free T4
  • Variable expressivity

Inheritance pattern: Autosomal dominant with reduced penetrance

What Can Be Learned From This Test

Testing is performed by sequencing the entire coding region and the promoter of the PAX8 gene. This will detect point mutations, small deletions and small insertions. It will not detect a partial or whole gene deletion or duplication.

A negative test result does not rule out a genetic cause of congenital hypothyroidism. Other genes are known to be associated with this condition, and this test will only detect mutations in PAX8.

Sample Requirements

Draw 2ml–4ml of blood in EDTA/purple-top tube (minimum of 1ml–2ml for infants).

Turnaround time: 10-14 business days

CPT Codes and Cost

Full Gene Sequencing

  • Code: 81479
  • Cost: $1,025

Known Variant Testing

  • Code: 81479
  • Cost: $225

Additional Information