Urine sialic acid was measured in 246 patients evaluated for possible neurodegenerative disorders. Total, free, and bound sialic acid excretion declined significantly with patients' ages. Among 11 patients (4.5%) with age-related excretion rates greater than 2 standard deviations above the mean, 5 had the following disorders: free sialic acid storage disease, mucolipidosis type II, pseudohypoparathyroidism, sinus histiocytosis, and probable Sanfilippo syndrome. Although the remaining 6 were undiagnosed, 2 exhibited deteriorating courses and the other 4 presented variable combinations of organomegaly, developmental delay or mental retardation, seizures, facial dysmorphism, or bony abnormalities. Thus, these individuals also may have metabolic disorders with abnormal excretions of sialic acid-containing compounds. With awareness of age-related excretion rates, sialic acid screening is most useful for the sialidoses, mucolipidoses, and disorders of free sialic acid metabolism.
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health
- Developmental Neuroscience
- Clinical Neurology