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.



Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.

See Compliance Statement C: www.aruplab.com/CS
Note
CPT Code(s)
81406
Components
Component Test Code*Component Chart Name
2006698Galactosemia (GALT) Sequencing Specimen
2006699Galactosemia (GALT) Sequencing Interp
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Cross References
  • Galactosemia Carrier Testing
  • Galactosemia Confirmation Test
  • Galactosemia genotyping
  • GALT DNA sequencing