Genes
COL1A1
Test Guide
Infantile cortical hyperostosis or Caffey disease is a dominantly inherited bone phenotype that is often identified in infancy with irritability, fever, soft tissue swelling and decreased movement of the involved limb. Radiographs reveal subperiosteal new bone formation without fracture. The hyperostosis of long bones, ribs or the mandible often resolves within months and may recur in childhood. The clinical description in more recent reported families includes short stature, compression fractures, scoliosis and genu varus. The disorder is associated with a c.3040C>T, p.Arg836Cys sequence variant, in exon 41 of COL1A1 The sensitivity of directed DNA sequencing of this region of COL1A1 in infants with the Caffey phenotype is roughly 90%. The mechanism by which the variant contributes to the phenotype is presently unknown.
In infants (or pregnancies) with normal directed COL1A1 sequencing, a second recurrent Caffey phenotype has emerged. In this population, the hyperostosis is prenatal in onset with many detected at premature delivery with poor lung maturation and stillbirth. Recurrence in siblings born to unaffected parents is observed in this group. Search for a genetic cause of this variable Caffey phenotype is ongoing.
Methodology
Sanger Sequencing: Targeted analysis of the COL1A1 c.3040C>T variant associated with Caffey disease
Specimen Requirements
BLOOD IS PREFERRED.
BLOOD: 2 EDTA (purple top) tubes
Adults: 5-10cc
Children: 3-5cc
Infants: 2-3cc
Whole blood may be stored up to 5-7 days in the refrigerator before shipping.
DNA:
5 µg DNA
SALIVA:
Oragene Saliva samples are accepted
PRENATAL:
Amniocytes or Cultured CVS Cells: Two confluent T-25 flasks of cultured amniocytes or CVS cells, well-labeled as Prenatal Sample. Please call ahead to notify the CDL that a prenatal sample will be coming.
Special Instructions
Blood samples (or DNA) should be well labeled with patient’s full name and an identifying number.
Ship sample at room temperature with overnight delivery.
Clinical information outlining the indication for the requested tests and pertinent medical history and family history is a necessary component of testing. Please include a clinic note when available.
Radiographs are welcome for analysis by Laboratory Directors.
CPT Code & Cost
81403$350.00