Renal Hypouricemia Type 1 & Type 2

Gene: SLC22A12 (URAT1)

Protein: solute carrier family 22, member 12

Gene: SLC2A9 (GLUT9)

Protein: solute carrier family 2, facilitated glucose transporter member 9

Clinical Characteristics

  • Impaired reabsorption of uric acid by the kidney:
    • Decreased serum uric acid level of less than 2.0 mg/dL (<119 umol/L)
    • Increased fractional excretion of uric acid (FEUA) of greater than 10%
  • Majority of individuals are asymptomatic
  • Some have urolithiasis
  • Some are predisposed to exercise-induced acute kidney injury (EI-AKI)
  • RHUC1 is due to SLC22A12 mutations
  • RHUC2 is due to SLC2A9 mutations

Inheritance pattern:  Autosomal recessive

What Can Be Learned From This Test

Testing is performed by sequencing all exons and the surrounding intronic regions of the SLC22A12 and SLC2A9 genes. This will detect point mutations, small deletions and small insertions. It will not detect a partial or whole gene deletion or duplication.

To date, a deletion of exon 7 as well as a large duplication of exons 1a — 11, have been reported in the SLC2A9 gene. A copy number assay for these regions of SLC2A9 can also be performed.

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: $550


  • Code: 81479
  • Cost: $800

Deletion/Duplication Analysis

  • Code: 81479
  • Cost: $350

Known Variant Testing

  • Code: 81479
  • Cost: $225

Additional Information

OMIM entries