Carrier screening or diagnostic testing for lipoamide dehydrogenase deficiency 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: Lipoamide dehydrogenase deficiency has a variable presentation that ranges from early-onset neurologic disease to adult-onset disease which is primarily hepatic. Early-onset neurologic disease presents in infancy with hypotonia, lethargy, vomiting and progressive encephalopathy resulting in death within the first or second year of life. Adult-onset primarily hepatic disease has a variable onset from infancy to the fourth decade and presents with liver injury or failure that is usually preceded by nausea and vomiting.
Incidence: 1 in 35,000 in Ashkenazi Jewish individuals.
Inheritance: Autosomal recessive.
Cause: DLD pathogenic variants.
Variants Tested: p.Y35X (c.104dupA), p.G229C (c.685G>T).
Clinical Sensitivity: 99 percent in Ashkenazi Jewish individuals; unknown in other ethnicities.
Methodology: Polymerase chain reaction (PCR) and fluorescence monitoring.
Analytical Sensitivity and Specificity: Greater than 99 percent.
Limitations: Variants other than those tested will not be detected. Diagnostic errors can occur due to rare sequence variations.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
|2013736||Lipoamide Dehydrogenase Def, Specimen|
|2013737||Lipoamide Dehydrogenase Def, Allele 1|
|2013738||Lipoamide Dehydrogenase Def, Allele 2|
|2013739||Lipoamide Dehydrogenase Def, Interp|
- Dihydrolipoamide dehydrogenase deficiency