This is a second-tier test and REQUIRES APPROVAL from ARUP's Genetic Counselor (800-242-2787 x2141) before ordering. Preferred initial test is the sequencing and deletion/duplication test.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 2 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Ambient: 72 hours; Refrigerated: 1 week; Frozen: Unacceptable
Characteristics: Mutations in the GLI3 gene cause multiple disorders. The most common disorders are Pallister-Hall syndrome (PHS) and Greig Cephalopolysyndactyly syndrome (GCPS).
PHS is characterized by hypothalamic hamartoma, postaxial/central polydactyly, and bifid epiglottis. Some individuals may exhibit imperforate anus, renal, genitourinary, pulmonary, or non-polydactyly skeletal anomalies.
GCPS is characterized by preaxial polysyndactyly, hypertelorism, and macrocephaly. Severe cases may exhibit seizures, hydrocephalus, and/or intellectual disability.
Inheritance: Autosomal dominant
Cause: Pathogenic germline mutations in the GLI3 gene.
Clinical sensitivity: PHS-unknown; GCPS-5-10 percent
Methodology: Multiplex ligation-dependent probe amplification (MLPA) to detect large exonic GLI3 deletions and duplications.
Analytical sensitivity and specificity: Greater than 98 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Single base pair substitutions, small deletions/duplications, regulatory region mutations, and deep intronic mutations are not detected. The breakpoints of large deletions/duplications are not determined.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.
|Component Test Code*||Component Chart Name||LOINC|
|2011425||GLI3-Related Disorders DelDup - Specimen||31208-2|
|2011426||GLI3-Related Disorders DelDup - Interp||35474-6|
- Greig Cephalopolysyndactyly syndrome (GCPS)
- Pallister-Hall syndrome (PHS)