Galactosemia Type 1 Sequencing

Galactosemia is a rare genetic metabolic disorder that affects an individual's ability to metabolize the sugar galactose properly. Although the sugar lactose can metabolize to galactose, galactosemia is not related to and should not be confused with lactose intolerance.(1) Its incidence is about 1 per 60,000 births for Caucasians. In other populations the incidence rate differs. Galactosemia is also very common within the Irish Traveller population.(2)

Galactosemia is inherited in an autosomal recessive manner, meaning a child must inherit one defective gene from each parent to show the disease. Heterozygotes are carriers, because they inherit one normal gene and one defective gene.(3) Carriers show no symptoms of galactosemia.

Galactose is converted into glucose by the action of three enzymes, known as the Leloir pathway. There are diseases associated with deficiencies of each of these three enzymes:

Type 1, GALT gene, 9p13 locus, galactose-1-phosphate uridyl transferase enzyme

Type 2, GALK1 gene, 17q24 locus, galactokinase enzyme

Type 3, GALE gene, 1p36-35 locus, UDP galactose epimerase enzyme

Methodology: Sequencing for eight common mutations/PCR for 5kb deletion

Purpose:Confirmation of Clinical Diagnosis

ICD-9 Code 271.1

Test Requisition: Sequencing Requisition

CPT Code: 81406 Cost: $473.00

Turn-around-time: 5-7 days