Ordering Recommendation

Recommended test to confirm a clinical diagnosis or suspected diagnosis of CHARGE syndrome.

Mnemonic
CHD7 FGS
Methodology

Polymerase Chain Reaction/Sequencing

Performed

Sun-Sat

Reported

28-35 days

New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
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
Interpretive Data

Background Information for CHARGE Syndrome (CHD7) Sequencing:
Characteristics: CHARGE is an acronym for the major features of the condition, which are Coloboma, Heart defects, choanal Atresia, Restricted growth and delayed development, Genital abnormalities and Ear anomalies. This condition has a highly variable presentation.
Incidence: About 1 in 10,000.
Inheritance: Autosomal dominant.
Cause: Pathogenic CHD7 gene mutations.
Clinical Sensitivity: Approximately 90 percent for individuals fulfilling clinical criteria for CHARGE.
Methodology: Bidirectional sequencing of all coding regions and intron-exon boundaries of the CHD7 gene.
Analytical Sensitivity and Specificity:  99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Regulatory region mutations, deep intronic mutations and large deletions/duplications in CHD7 will not be detected.

Compliance Category

Laboratory Developed Test (LDT)

Note
Hotline History
N/A
CPT Codes

81407

Components
Component Test Code* Component Chart Name LOINC
2012610 CHD7 FGS Sequencing Specimen
2012611 CHD7 FGS Sequencing 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
CHARGE Syndrome, CHD7 Sequencing