Diagnostic testing and carrier screening for FGS1.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Characteristics: Mental retardation, congenital hypotonia, constipation/anal anomalies, characteristic face, brain anomalies, behavioral issues and extreme clinical variability.
Incidence: Estimated at 1 in 15,000.
Inheritance: X-linked dominant with reduced penetrance for MED12 gene mutations.
Cause: At least seven X-linked loci have been associated with FG syndrome. The deleterious p.R961W (c.2881C>T) MED12 gene mutation is causative for FG cases localized to Xq13 (FGS1 locus).
Penetrance: Believed 100 percent in males; variable in females.
Clinical Sensitivity: Approximately 7 percent for FG syndrome.
Methodology: Polymerase chain reaction and fluorescence monitoring.
Analytical Sensitivity and Specificity: 99 percent.
Limitations:Diagnostic errors can occur due to rare sequence variations.MED12 gene mutations, other than R961W, and mutations in other causative genes, will not be detected.
This test is performed pursuant to an agreement with Roche Molecular Systems, Inc.
|Component Test Code*||Component Chart Name||LOINC|
|0051753||FG Syndrome, FGS1 (MED12) R961W Mutation|
|2002914||FG Syndrome Specimen|
- FG Syndrome type 1
- MED12 (R961W)