Canavan Disease, DNA Analysis

CPT 81200
Synonyms
  • Aminoacylase-2 Deficiency
  • ASP(A) Deficiency
  • Aspartoacylase Deficiency

Test Details

Use

Identification of carrier and affected individuals for four mutations, E285A, Y231X, 433-2A>G, and A305E, associated with Canavan disease. Prenatal testing is available.

Special Instructions

If cultured cells are needed, an additional 7-12 days may be required. Additional culture fee may be included.

Limitations

This test detects ∼98% of mutations responsible for Canavan disease in Ashkenazi Jews, and ∼60% of mutations in non-Jewish Caucasians.

Methodology

Polymerase chain reaction (PCR); primer extension; flow-sorted bead array analysis of four aspartoacylase gene mutations

References

American College of Obstetricians and Gynecologists Committee on Genetics. ACOG committee opinion. Nº 298, August 2004. Prenatal and preconceptional carrier screening for genetic diseases in individuals of Eastern European Jewish descent. Obstet Gynecol. 2004 Aug; 104(2):425-428. 15292027
Kaul R, Gao GP, Aloya M, et al. Canavan disease: Mutations among Jewish and non−Jewish patients. Am J Hum Genet. 1994 Jul; 55(1):34-41. 8023850
Matalon R. Canavan disease: Diagnosis and molecular analysis. Genet Test. 1997; 1(1):21-25. 10464621
Monaghan KG, Feldman GL, Palomaki GE, Spector EB; Ashkenazi Jewish Reproductive Screening Working Group; Molecular Subcommittee of the ACMG Laboratory Quality Assurance Committee. Technical standards and guidelines for reproductive screening in the Ashkenazi Jewish population. Genet Med. 2008 Jan; 10(1):57-72. 18197058

Additional Information

Canavan disease (OMIM 271900) is an autosomal recessive progressive leukodystrophy that often leads to death in the first decade of life. It is caused by a deficiency of the enzyme, aspartoacylase (ASPA). Canavan disease is more common in the Ashkenazi Jewish population where about 1 in 40 persons is estimated to be a carrier. Couples who are both carriers have a one in four risk of having a child with Canavan disease. A305E is the Canavan mutation found among individuals of non-Ashkenazi Jewish ancestry. DNA test results must be combined with clinical information for the most accurate interpretation.

Specimen Requirements

Information on collection, storage, and volume

Specimen

Whole blood, amniotic fluid, chorionic villus sample (CVS) (submission of maternal blood is required for fetal testing), or LabCorp buccal swab kit (buccal swab collection kit contains instructions for use of a buccal swab)

Volume

7 mL whole blood, 10 mL amniotic fluid, 20 mg CVS, or LabCorp buccal swab kit

Minimum Volume

3 mL whole blood, 5 mL amniotic fluid, 10 mg CVS, or two buccal swabs

Container

Lavender-top (EDTA) tube, yellow-top (ACD) tube, sterile plastic conical tube or two confluent T25 flasks for fetal testing, or LabCorp buccal swab kit

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Frozen specimen; hemolysis; quantity not sufficient for analysis; improper container; one buccal swab; wet buccal swab