One form is characterized by episodic vomiting, lethargy, dehydration, ketosis, and increased susceptibility to infection; a second form by generalized hypotonia, lethargy, absence of reflexes, and periodic myoclonic jerks. [medical-dictionary.thefreedictionary.com]

Abstract A 31-year-old man with spastic paraparesis (diagnosed when he was 10 years old) and hyperglycinemia (diagnosed when he was 19 years old) had an intermittently swollen right eye and blurred vision. [ncbi.nlm.nih.gov]