Ordering Recommendation

Prenatal test for fetuses with ultrasound findings suggestive of CHARGE syndrome, or for individuals who had a previous child with CHARGE syndrome, but do not know the specific mutation.

Mnemonic
CHD7 FE
Methodology

Polymerase Chain Reaction/Sequencing

Performed

Sun-Sat

Reported

14-21 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

Cultured Amniocytes: Four T-25 flasks at 80 percent confluent cultured amniocytes. If the client is unable to culture amniocytes, this can be arranged by contacting Client Services at (800) 522-2787. 
Or Amniotic Fluid
: Amniotic fluid submissions will require cultured amniocytes (Order Amniocyte Culture, Four Flask).
AND Maternal Whole Blood: Lavender (K2EDTA), Lavender (K3EDTA), Pink (K2EDTA), or Yellow (ACD Solution A or B).

Specimen Preparation

Cultured Amniocytes: Fill flask with culture media. Transport four T-25 flasks at 80 percent confluent of culture amniocytes filled with culture media.
Amniotic Fluid
: Transport 10 mL unspun fluid (Min: 5 mL)
Maternal Whole Blood
: Transport 3 mL whole blood (Min: 1 mL)

Storage/Transport Temperature

Cultured Amniocytes: CRITICAL ROOM TEMPERATURE. Must be received within 48 hours of shipment due to liability of cells.
Amniotic Fluid:
Room temperature.
Maternal Whole Blood:
Room temperature.

Unacceptable Conditions

Plasma or serum.

Remarks
Stability

Fetal Specimen: Ambient: 48 hours; Refrigerated: Unacceptable; Frozen: Unacceptable
Maternal Whole Blood:
Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable

Reference Interval
Interpretive Data

Background Information for Charge Syndrome (CHD7) Sequencing, Fetal:
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, 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 fetuses 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.

For quality assurance purposes, ARUP Laboratories will confirm the result at no charge following delivery. Order Confirmation of Fetal Testing and include a copy of the original fetal report (or the mother's name and date of birth) with the test submission. Please contact an ARUP genetic counselor at (800) 242-2787 extension 2141 prior to specimen submission.

Compliance Category

Laboratory Developed Test (LDT)

Note

Maternal sample is recommended for proper test interpretation.

Hotline History
N/A
CPT Codes

81407; 81265 Fetal Cell Contamination (FCC)

Components
Component Test Code* Component Chart Name LOINC
0050548 Maternal Contamination Study Fetal Spec 59266-7
0050612 Maternal Contam Study, Maternal Spec 31208-2
2012718 CHD7 FE Sequencing, Specimen 31208-2
2012719 CHD7 FE Sequencing, Interpretation 42240-2
* 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, Fetal