Galactosemia (GALT), Sequencing
2006697
Ordering Recommendation
Molecular (DNA) test to identify the causative mutations for galactosemia when GALT enzyme activity is consistent with galactosemia and the 9 mutation panel does not identify two causative mutations. To diagnose or rule out galactosemia, refer to Galactosemia (GALT) Enzyme Activity and 9 Mutations (0051175).
Mnemonic
GALT FGS
Methodology
Sequencing
Performed
Sun- Sat
Reported
14-21 days  
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
 
Collect
Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).  
Specimen Preparation
Transport 3 mL whole blood. (Min: 1 mL)  
Storage/Transport Temperature
Refrigerated  
Unacceptable Conditions
  
Remarks
  
Stability
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable  
Reference Interval
By Report  
Interpretive Data
Background Information for Galactosemia (GALT), Sequencing:
Characteristics:
Vomiting, diarrhea, feeding problems, failure to thrive, hepatocellular damage, bleeding, sepsis, mental retardation, and neonatal death. If treated early, most symptoms resolve, although speech, motor problems, developmental delay and premature ovarian failure may persist.
Incidence:
Approximately 1 in 30,000.
Inheritance:
Autosomal recessive
Penetrance:
100 percent for severe mutations.
Cause:
Pathogenic galactose-1-phosphate uridyl transferase (GALT) gene mutations.
Clinical sensitivity:
98 percent.
Methodology:
Bidirectional sequencing of the entire GALT coding region, intron/exon boundaries and partial 5'UTR.
Analytic Sensitivity & Specificity:
99 percent.
Limitations:
Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations, deep intronic mutations, and large deletions/duplications will not be detected. Mutations in genes other than GALT are not evaluated.





See Compliance Statement C: www.aruplab.com/CS
Statement C: The performance characteristics of this test were validated by ARUP Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test; however, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. ARUP is authorized under Clinical Laboratory Improvement Amendments (CLIA) and by all states to perform high-complexity testing.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
 
Note
 
CPT Code(s)
81406
Components
Component Test Code*Component Chart NameLOINC
2006698Galactosemia (GALT) Sequencing Specimen 
2006699Galactosemia (GALT) Sequencing Interp 
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Aliases
  • Galactosemia Carrier Testing
  • Galactosemia Confirmation Test
  • Galactosemia genotyping
  • GALT DNA sequencing