Specimen:

Various

Collection Medium:

Alternate
Collection Media:

Pink top tube (EDTA sprayed)

Minimum:

Specimen must arrive reference laboratory within 96 hours of 
collection.

Collect blood in a lavender top (EDTA) tube(s), and send 4.0 mL of EDTA 
whole blood in original VACUTAINER(S). Invert several times to mix 
blood. Forward unprocessed whole blood promptly at ambient temperature.
Preferred minimum:  3.0 mL
Absolute minimum:  1.0 mL

Please call the Clinical Pathology Core Laboratory at 356-3527 for 
other specimen types.

Analytic Time:

1 week

Reference Range:

An interpretive report will be provided.

Comments:

Useful for:
1) Confirmation of diagnosis of galactosemia

2) Identifying galactosemia carriers in families where there is an 
affected individual of know genotype

3) Documenting germline mutations

4) Resolution of potential Duarte and Duarte/Los Angeles genotypes

5) Follow-up testing for low or borderline GALT enzyme tests

This interpretive report includes an overview of the results and their 
significance, a correlation to available clinical information, elements 
of differential diagnosis, and recommendations for additional testing.  
For diagnostic purposes, results should be interpreted in the context 
of biochemical results.

CAUTIONS:
Many disorders may present with symptoms similar to those present in 
galactosemia.  Therefore, biochemical testing is recommended to 
establish the diagnosis of galactosemia prior to DNA analysis.

This panel will be run only when the GALT enzyme level is <18.4 U/g of 
hemoglobin (GALT reference range = 18.5-28.5 U/g of hemoglobin) or if 
enzyme testing cannot be performed.

Not all individuals with galactosemia demonstrate the mutations 
included in this panel.  The absence of such mutations, therefore, does 
not eliminate the possibility of the presence of a mutation in another 
region of the gene.

Methodology:

Direct Mutation Analysis by Polymerase Chain Reaction (PCR)

CPT Code:

83890, 83896(x6), 83898(x6), 83912