Description:

The deficiency of hypoxanthine phosphoribosyl transferase (HPRT) results in the Lesch-Nyhan syndrome. This assay measures the conversion of ¹⁴C-hypoxanthine into inosine monophosphate. Lesch-Nyhan syndrome is an X-linked disorder and is almost universally observed in males. The protocol uses the natural substrate, hypoxanthine, and measures the production of inosine. This protocol is not useful for carrier detection or other diagnostic testing in females.

Specimen Requirements:

The assay is routinely performed on red blood cells. Draw 3-5 ml in a yellow top (ACD) tube and ship to us on wet ice in an insulated container by overnight express. Sample must arrive at our location within 48 hrs. For fibroblasts, send two T25 flasks of confluent cells in an insulated container by overnight carrier. Contact the laboratory for information regarding prenatal diagnosis studies.

Normal Range:

Red Blood Cells:400-2200 nmoles/min/gm Hb
Skin Fibroblasts:1.0-3.4 nmoles/min/mg protein

Turnaround Time:

Amniotic Cell Culture, Cultured Chorionic Villus Cells: 3 weeks
Red Blood Cells: 2 weeks
Skin fibroblasts assays are growth dependent.

CPT Codes and Prices:

Amniotic Cell Culture: 82489x2, 82658x2, 84155x2, 88235x4, 88240x2, 83891x2, 83894x8, 83901x8, 83912x2
Cultured Chorionic Villus Cells: 82489x2, 82658x2, 84155x2, 88235x4, 88240x2, 83891x2, 83894x8, 83901x8, 83912x2
Red Blood Cells: 82658, 83026
Skin Fibroblast Culture: 82489, 82658, 84155, 88233, 88240

Shipping Information

Forms:

>> Biochemical Requisition
>> Biochemical Prenatal Consent
>> Prenatal Requisition

Test Codes:

Amniotic Cell Culture: 4570
Cultured Chorionic Villus Cells: 4571
Red Blood Cells: 4572
Skin Fibroblast Culture: 4573

Medical Genetics Laboratories
Baylor College of Medicine · Houston, TX 77030
Phone: 1-800-411-GENE · Fax: 713-798-6584
E-mail: