| Rare Disease | Involved Enzyme | Main Symptoms |
|---|---|---|
| Aromatic L-amino acid decarboxylase deficiency [61] | DOPA decarboxylase | delay in development, abnormal movements, oculogyric crisies, vegetative symptoms |
| Cystathioninuria [69] | Cystathionine-γ-lyase | abnormal urinary excretion of cystathionine, fibrotic liver |
| GABA-transaminase deficiency [70] | γ-aminobutyric acid-transaminase | hyperreflexia, hypotonia, lethargia, macrosomia, mental retardation, and siezures |
| Gilles de la tourette syndrome [71] | Histidine decarboxylase | arm thrusting, eye blinking, repeated throat clearing or sniffing, shoulder shrugging |
| Glycine encephalopathy [72] | P protein (a pyridoxal phosphate-dependent glycine decarboxylase) | mental retardation, hypotonia, seizures, brain malformations, ataxia |
| Hereditary sensory and autonomic neuropathy Type I [73] | Serine palmitoyltransferase | sensory deficit in the distal portion of the lower extremities, chronic perforating ulcerations of the feet and progressive destruction of underlying bones, sweating |
| Homocystinuria [74] | Cystathionina-β-syntase | high level of homocysteine, endothelial injury, isk of other artery or vein diseases |
| Ornithine aminotransferase deficiency (Gyrate atrophy) [75] | Ornithine aminotransferase | poor vision at night or in dim light, peripheral vision loss |
| Primary hyperoxaluria Type I [76] | Alanine:glyoxylate aminotransferase | oxalosis, nephrocalcinosis urolithiasis, nephrolithiasis, kidney stones |
| Smith-Magenis syndrome [77] | Serine hydroxymethyltransferase | square-shaped face with deep-set eyes, engaging personalities, short stature, scoliosis, reduced sensitivity to pain and temperature, and a hoarse voice |
| Stiff-Man Syndrome [78] | Glutamic Acid Decarboxylase | muscle rigidity that waxes and wanes with concurrent spasms, encephalomyelitis, epilepsy, cerebral palsy, or cerebellar deficits |
| Type II Tyrosinemia (Richner-Hanhart syn-drome) [79] | Tyrosine aminotransferase | excessive tearing, photophobia, eye pain and redness, and painful skin lesions on the palms and soles, mental retardation |
| Xanthurenic aciduria [80] | L-Kynurenine hydrolase | vomiting, jaundice, high excretion of Xanthurenic acid |
| "X-linked" sideroblastic anemia [81] | δ-aminolevulinate synthase | microcytic red blood cells hypochromic an abnormal accumulation of iron in red blood cells |