For patients with mutations not identified by full gene sequencing, a separate deletion/duplication assay is available using a targeted CGH array (HH).
1. Vockley and Ensenauer. Isovaleric Acidemia: New Aspects of Genetic and Phenotypic Heterogeneity. Am J Med Genet Part C (Seminars in Medical Genetics) 142C:95-103 (2006).
2. Sweetman and Williams. 2001. Branched chain organic acidurias. In: Scriver C, Beaudet AL, Sly W, Valle D, editors. The metabolic and molecular basis of inherited disease, 8th edition. New York: McGraw-Hill, p.2125-2164.
3. Vockley et al. Identification of the molecular defects responsible for the various genotypes of isovaleric acidemia. Prog Clin Biol Res 1992, 375:533-540.
4. Vockley et al. Exon skipping in IVD RNA processing in isovaleric acidemia caused by point mutations in the coding region of the IVD gene. Am J Hum Genet 2000, 66:356-367.
5. Ensenauer et al. A Common Mutation Is Associated with a Mild, Potentially Asymptomatic Phenotype in Patients with Isovaleric Acidemia Diagnosed by Newborn Screening. Am J Hum Genet 2004, 75:1136-1142.
6. Lin et al. Genetic mutation profile of isovaleric acidemia patients in Taiwan. Mol Genet Metab 2007, 90:134-139.
7. Schulze et al. Expanded newborn screening for inborn errors of metabolism by electrospray ionization-tandem mass spectrometry: results, outcome, and implications. Pediatrics 2003, 111(6 Pt 1):1399-406.
- Confirmation of clinical/biochemical diagnosis of IVA
- Carrier testing in adults with a family history of IVA
Clinical Sensitivity: 38/38 mutations identified in 19 patients ; 12/12 mutations identified in 6 patients .
Analytical Sensitivity: ~99%
Results of molecular analysis must be interpreted in the context of the patient's clinical and/or biochemical phenotype.
Prevalence: IVA has an estimated incidence of 1:62,500 live births .
Submit only 1 of the following specimen types
Preferred specimen type: Whole Blood
Type: Whole Blood
Specimen Requirements:In EDTA (purple top) or ACD (yellow top) tube:
Infants (<2 years): 2-3 ml
Children (>2 years): 3-5 ml
Older Children & Adults: 5-10 ml
Specimen Collection and Shipping: Refrigerate until time of shipment. Ship sample within 5 days of collection at room temperature with overnight delivery.
Specimen Requirements:OrageneTM Saliva Collection kit (available through EGL) used according to manufacturer instructions.
Specimen Collection and Shipping: Store sample at room temperature. Ship sample within 5 days of collection at room temperature with overnight delivery.
- Plasma Amino Acid (AA) analysis, Urine Organic Acids (OA), and Plasma Acylcarnitine Profile (AR) are used in the diagnoses of a patient with IVA
- Custom Diagnostic Mutation Analysis (KM) is available to family members if mutations are identified by sequencing.
- A Deletion/Duplication Assay is available separately for individuals where mutations are not identified by sequence analysis. Refer to the test requisition or contact the laboratory for more information.
- Prenatal testing is available for known familial mutations only. Please call the Laboratory Genetic Counselor before collecting a fetal sample.