Limb Defects Sequencing Panel


Related Gene(s): GLI3, HOXD13, ROR2, SALL1, SALL4, TBX5, WNT7A, ZRS

Congenital limb defects (CLDs) are relatively common, complex disorders of upper and/ or lower limb development. The incidence of congenital limb defects is estimated to be at 1 in 1,500 to 1 in 3,000 live births and represents the second most common congenital malformation after cardiac defects. Common clinical presentation includes polydactyly, syndactyly, limb reduction or long bone deficiencies, and multiple anomalies and/or generalized skeletal syndromes. Genetic syndromes, including CLD, may be caused by germline mutations in genes involved in cell fate regulation and patterning during embryogenesis. Phenotypes resulting from many of these can be quite variable. Genetic testing may be clinically useful in the postnatal period for individuals that display characteristic features or in the prenatal period for fetuses that present with certain ultrasound findings (polydactyly, limb reduction, etc.) after a normal chromosome analysis. Our Limb Defects Sequencing Panel tests for the following genes: GLI3, SALL1, SALL4, TBX5, ROR2, HOXD13, WNT7A, and ZRS (sonic hedgehog (SHH) cis-regulator).

Testing can be ordered a select number of these genes, or the entire panel. Additionally, targeted mutation analysis can be performed if a previous familial mutation has already been identified. Prenatal diagnosis is also available. Prior to ordering prenatal testing, please contact our laboratory at 212-241-7518 to discuss.


Specimen Requirements

Prenatal

  • Chorionic villi: 4 mg in conical tube with sterile saline or transport media
  • Amniotic fluid: 15 mL in conical tube
  • Cultured cells: Two confluent T-25 flasks

  • Additionally, please send:
  • Maternal blood: 5-10 mL in EDTA tube (lavender top) required to perform MCC studies on all prenatal samples and in case maternal confirmation studies are necessary
  • Paternal blood: 5-10 mL in EDTA tube (lavender top) in case paternal confirmation studies are necessary

Postnatal

  • For adults
  • Blood: Two 5-10 mL tubes with EDTA (lavender top) or two 5-10 mL tubes with ACD (yellow top) from the patient
  • Additionally, please send two 5-10 mL tubes with EDTA (lavender top) or two 5-10 mL tubes with ACD (yellow top) from both parents

  • For newborns or children
  • Blood: 2 mL in pediatric EDTA tube (lavender top) or 2 mL in pediatric ACD tube (yellow top) from patient
  • Additionally, please send two 5-10 mL tubes with EDTA (lavender top) or two 5-10 mL tubes with ACD (yellow top) from both parents

Ordering Information

Shipping

  • Ship at room temperature

Turnaround Time

  • 2-3 weeks


Resources

General Test Requisition
Limb Defects Sequencing Panel Information Sheet