Carrier screening or diagnostic testing for familial dysautonomia for individuals of Ashkenazi Jewish descent.
- 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
- Plasma or serum. Specimens collected in sodium heparin or lithium heparin tubes.
- Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 1 month
Characteristics: Familial dysautonomia is a debilitating disease caused by abnormal development and survival of sensory, sympathetic and parasympathetic neurons. Symptoms include gastrointestinal dysfunction, vomiting and autonomic crises, recurrent pneumonia, altered sensitivity to pain and temperature, scoliosis, and cardiovascular instability. Other characteristics include infantile hypotonia, deteriorating wide-based ataxic gait, and decreased life expectancy.
Incidence: 1 in 3,600 Ashkenazi Jewish individuals.
Inheritance: Autosomal recessive.
Cause: IKBKAP pathogenic variants.
Variants Tested: p.R696P (c.2087G>C) and c.2204+6T>C.
Clinical Sensitivity: 99 percent in Ashkenazi Jewish individuals, unknown in other ethnicities.
Methodology: Polymerase chain reaction (PCR) and fluorescence monitoring.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Variants other than p.R696P (c.2087G>C) and c.2204+6T>C will not be detected. Diagnostic errors can occur due to rare sequence variations.
|Component Test Code*||Component Chart Name||LOINC|
|0051465||Fam. Dysautonomia (IKBKAP), Allele 1||32653-8|
|0051466||Fam. Dysautonomia (IKBKAP), Allele 2||32653-8|
|0051467||Fam. Dysautonomia (IKBKAP), Interp||46992-4|
|2001327||Fam. Dysautonomia (IKBKAP), Specimen|
- Riley-Day syndrome