Lipoamide Dehydrogenase Deficiency (DLD), 2 Variants

Background Information for Lipoamide Dehydrogenase Deficiency (DLD), 2 Variants:
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.