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Filaggrin (FLG) 2 Mutations
2007883
Ordering Recommendation

Confirm diagnosis of ichthyosis vulgaris and differentiate vulgaris from other forms of ichthyosis.

Mnemonic
FLG
Methodology
Polymerase Chain Reaction/Fluorescence Monitoring
Performed
Sun-Sat
Reported
7-10 days
New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
ARUP Consult®
Disease Topics
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 Filaggrin (FLG) 2 Mutations
Characteristics:
Two mutations in the FLG gene, c.1501C>T (R501X) and c.2282del4, are associated with ichthyosis vulgaris, keratosis pilaris and an increased risk for atopic disease, including atopic dermatitis (eczema), allergic rhinitis and asthma.
Incidence: Approximately 7-10 percent of Caucasian individuals have one or more mutations in the FLG gene.
Inheritance: Autosomal dominant with reduced penetrance.
Penetrance: 100 percent in individuals with two FLG loss-of-function mutations and approximately 88 percent in those with one mutation, though severity of symptoms is highly variable. Some individuals may be asymptomatic.
Cause:
The presence of at least one pathogenic FLG gene mutation. Mutations in other genes may also be causative.
Mutations Tested:FLG gene mutations c.1501C>T (R501X) and c.2282del4.
Clinical Sensitivity: Estimated to be 80 percent in Caucasians.
Methodology: Multiplex PCR followed by fluorescent monitoring using hybridization probes.
Analytical Sensitivity and Specificity: 99 percent.
Limitations:FLG mutations other than c.1501C>T (R501X) and c.2282del4 will not be evaluated. Diagnostic errors can occur due to rare sequence variations.

Note
CPT Code(s)
81401
Components
Component Test Code*Component Chart NameLOINC
2007884Filaggrin (FLG) 2 Mutations Specimen
2007885Filaggrin R501X
2007886Filaggrin 2282Del4
2007887Filaggrin Interpretation
* 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.
Aliases