Canavan Disease, DNA Analysis

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)

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

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

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

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

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

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

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.