Gene Symbol: FGFR2
Chromosomal Locus: 10q26
Protein: Fibroblast growth factor receptor 2
Pseudonyms: exon 7/IIIa & exon 10/ IIIc, Craniosynostosis
TURNAROUND TIME: 15 days
Testing offered as a Craniodysmorphology screen or panel
Screen: 83890 x 1, 83892 x 6, 83894 x 3, 83898 x6, 83904 x 6, 83912 x 3
Panel: 83890 x 1, 83892 x 6, 83894 x 4, 83898 x 7, 83904 x 12, 83912 x 4
- Collect: Prefer two 5ml whole blood EDTA (lavender top) tube.
- Min. Collection: 0.7 ml whole blood EDTA.
- Transport: Blood EDTA at Room Temp shipped regular next day air (No Saturday delivery; store specimen refrigerated and ship Monday).
- Stability: Ambient: up to 7 days; Refrigerated: 2 weeks. Frozen: unacceptable
- Unacceptable Conditions: Serum. Frozen or severely hemolyzed blood. Clotted blood.
- Prenatal testing: Direct: 5ml direct unspun amniotic fluid or 15mg CVS tissue with a backup flask growing. Culture: confluent T25 flask. Maternal blood sample is required for maternal cell contamination studies.
Counseling and informed consent are recommended for genetic testing. A consent form
is available as a resource but not required.
Incidence: Incidence: 1 in 2,000 for Craniosynostosis; 1 in 60,000 for Crouzon and Pfeiffer syndromes combined.
Inheritance: Spontaneous or inherited in an autosomal dominant manner. In the inherited form, the diseases are considered fully penetrant although variable expression is typical.
Disease Characteristics: Premature closure of the sutures between the bones of the skull, causingunicoronal or bicoronal craniosynostosis or cloverleaf skull. Also distinctive facial features and variable abnormalities of the hands and feet.
Molecular Genetic Mechanism: A variety of missense, nonsense and insertion/deletion mutations have been described. The majority of the mutations are located within exons 8 and 10 of the FGFR2 gene.
Clinical Sensitivity: 80%
Analytical Sensitivity: 99%
Test Limitations: Deletions of the entire gene or mutations outside the tested regions of the genes will not be detected. Rare diagnostic errors can occur due to primer or probe site mutations or rare polymorphisms.
INDICATIONS FOR USE:
- To determine the genetic basis for craniodysmorphology in an affected individual.
- To discriminate between syndromes with overlapping clinical symptoms.
- Prenatal diagnosis for individuals at risk or with ultrasound findings.