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Diagnostic Services

Genetics Lab


Galactosemia Mutation Analysis (8 mutations)

Galactosemia is an inherited disorder of galactose metabolism. Individuals with galactosemia are unable to break down galactose, a sugar found primarily in dairy products and some vegetables and legumes. Galactosemia is caused by a deficiency in the enzyme galactose-1-phosphate uridyltransferase, and individuals with galactosemia have mutations in the GALT gene. They also have elevated galactose-1-phosphate, a metabolite of galactose metabolism. Galactosemia affects about 1/10000 individuals and is included in the Washington State newborn screening program.

Test Name: Galactosemia (8 Mutations)
Test Code:
Test Description:
Analysis of the GALT gene for the following mutations:
p.S135L (c.404 C>T)
p.F171S (c.512 T>C)
p.Q188R (c. 563 A>G)
p.L195P (c.625 A>G)
p.Y209C (c. 625 A>G)
p.K285N (c.855 G>T)
p. N314D (c. 940 A>G) (Duarte variant)
p. L218L (c.1721 C>T) (LA variant)
This test is used to:
-provide additional information regarding diagnosed patients
-provide carrier testing for at-risk family members (mutations must be known)
-provide carrier testing to the general population
-provide prenatal testing (mutations must be known)
Related Tests: Galactose-1-phosphate, Quantitative  
This test is used to monitor known galactosemia patients

Galactose-1-phosphate Uridyl Transferase, Quantitative  
This test is used to diagnose galactosemia in a symptomatic individual. It can also be helpful for determining carrier status

Maternal Cell Contamination - DNA  
Maternal DNA is compared to fetal DNA to evaluate whether maternal cell contamination of the fetal sample has occurred.

Galactosemia DNA 1 Mutation  
This test is used to provide carrier testing or prenatal testing for at-risk family members. Mutations must be known.

Clinical Links: Galactosemia GeneReview
Mon - Fri
Turnaround Time:
2-3 weeks
PCR and sequencing
Reference Range:
Interpretive report provided
Consent Form:
Sample Requirements: Type
Whole blood: 1-3 mL in EDTA (purple top) or ACD (yellow top).
DNA: 5-10ug extracted DNA
Prenatal Samples: 2 T-25 flasks

Do not spin. Refrigerate blood samples which will not be immediately shipped.

Room temperature via overnight shipping. Ship cultured cells in appropriate media
Samples Received:
Mon – Fri 8:00 am – 5:00 pm PST
Special Considerations:
For prenatal testing mutations must be known and maternal cell contamination testing is required (ordered separately)
Please e-mail Client Services or call at 206-987-2617 with any billing questions
CPT Code:
Please e-mail Client Services or call at 206-987-2617 with any billing questions