The diagnosis of SSADH is usually made after birth (postnatally) during infancy or childhood (or, in some cases, later in life), based upon a thorough clinical evaluation, identification of characteristic physical findings, and a variety of specialized tests.
Due to the nonspecific nature and variability of associated symptoms, experts suggest that SSADH should be considered in any individual with two or more features of intellectual, language, and motor delay and abnormally diminished muscle tone (hypotonia) of unknown cause (idiopathic).
Specialized testing to confirm a diagnosis of SSADH typically includes studies (i.e., quantitative organic acid analysis in an appropriate specialist laboratory) that may detect increased concentrations of 4-hydroxybutyric acid (4-HBA) in urine (i.e., 4-hydroxybutyric aciduria) and molecular genetic testing to confirm the abnormal gene from each parent in the patient. (Note: As mentioned above, increased concentrations of 4-HBA may also be detected in plasma and cerebrospinal fluid. In addition, deficient SSADH activity has also been demonstrated in certain cells other than leukocytes.)
ALDH5A1 is the gene that codes for SSADH. Molecular genetic testing to identify bi-allelic mutations (abnormal changes found on both copies of a gene) or deletions in ALDH5A1 is used to make or confirm a diagnosis of SSADH. as noted above. This testing is usually ordered by the patient’s pediatrician, primary care physician, neurologist or a genetic counselor and can be completed at a number of facilities around the world. However, it is imperative that the testing facility specifically test for ALDH5A1. Fortunately, diagnostic capabilities to identify SSADH via gene sequencing have been enhanced because a number of companies assess the sequence of this gene on panels of genes for idiopathic developmental delay, epilepsy, and other clinical features.
Patients and families interested in obtaining information about the latest therapeutic and/or research information on SSADHD may wish to contact:
498 Lillian Court
P.O. Box 180622
Delafield, WI 53018 USA
Phone: (262) 646-5133
Physicians interested in obtaining clinical and/or therapeutic information on SSADHD may wish to contact:
Phillip L. Pearl, MD
Chief of Epilepsy and Clinical Neurophysiology
Boston Children’s Hospital
Harvard Medical School
300 Longwood Avenue,
Boston, MA 02115 USA
Physicians interested in obtaining clinical research information on SSADHD may wish to contact:
Michael Gibson, PhD, FACMG
Professor of Pharmacotherapy
Washington State University
College of Pharmacy
Room 210C, Health Sciences Building
Spokane, WA 99202 USA