Diagnosis and Testing
Can argininosuccinic aciduria be detected before birth?
Some parents may choose to have their child tested for argininosuccinic aciduria before they are born. This is known as prenatal diagnosis. If the gene change(s) that causes argininosuccinic aciduria are known in a family, then molecular genetic testing (which can detect these changes) can be used for prenatal diagnosis. A sample of tissue can be taken from the placenta to test for changes in the ASL gene. This test is called chorionic villus sampling. Another test is called amniocentesis, which involves taking a sample of the amniotic fluid that surrounds and protects a developing fetus. Cells known as amniocytes are taken from the fluid and studied for changes in the ASL gene. There are risks to the unborn baby of doing these tests before birth.
If molecular genetic testing is not possible, doctors can make a prenatal diagnosis through biochemical testing. This testing can detect elevated levels of argininosuccinic acid in amniotic fluid. Doctors can also use chorionic villus sampling or amniocentesis to test for the activity of the argininosuccinate lyase enzyme, which is reduced in infants with argininosuccinic aciduria.
Talk to your doctor or a genetic counselor in your area to discuss the risks and benefits of prenatal diagnosis. Genetic counselors can be found on the National Society of Genetic Counselors website in the United States, and in Canada at the Canadian Association of Genetic Counsellors website.
Nagamani SCS, Erez A, Lee B. Argininosuccinate Lyase Deficiency. GeneReviews website. Accessed July 1, 2017. https://www.ncbi.nlm.nih.gov/books/NBK51784
Haberle J. Argininosuccinic aciduria. OrphaNet website. Accessed July 1, 2017. http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=23