Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022568 (keratitis)
 5,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Richner-Hanhart's syndrome correspond to an hypertyrosinemia due to a deficiency of a soluble tyrosine amino-transferase. This recently described tyrosinosis has been called oculo-cutaneous tyrosinosis. This disease transmitted on a recessive way in amenable to a treatment by a low tyrosine diet. In an infant, 18 months old, presenting a bilateral dendritic keratitis, a punctiform keratosis of the extremities, a patchy leucokeratosis of the tongue and a mental ketardation, the hypertyrosinemia reached 52 mg per 100 ml and the urine demonstrated the presence of phenyl-atonic acids. There was no hepato-renal involvement. The deferency of soluble amino-transferase was studied on the hepatocytes and confirmed. The low tyrosine diet made the clinical and biological signs disappear. The improvement was noticeable from the first week on and continued during the 16 months of the follow-up. There was no ill effect of the special diet on the weight and height growth. The oculo-cutaneous tyrosinosis is similar to the experimental form obtained by Schweizer on the rat. The occurrence of intracellular tyrosine crystals probably damages lysosine membrane and the release lysomie proteases induce the cellular lesions.
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PMID:[Richner-Hanhart's syndrome or oculo-cutaneous tyrosinosis (about one case) (author's transl)]. 48 16

Tyrosinemia type II or Richner-Hanhart Syndrome (RHS) is an autosomal recessive disorder characterized by keratitis, palmoplantar keratosis, mental retardation, and elevated blood tyrosine levels. The disease is due to a deficiency of hepatic cytosolic tyrosine aminotransferase (TATc), an enzyme involved in the tyrosine catabolic pathway. Because of the high rate of consanguinity this disorder seems to be relatively common among the Arab and Mediterranean populations. RHS is characterized by inter and intrafamilial phenotypic variability. A large spectrum of mutations within TATc gene has been shown to be responsible for RHS. In the present study, we report the clinical features and the molecular investigation of RHS in three unrelated consanguineous Tunisian families including 7 patients with confirmed biochemical diagnosis of tyrosinemia type II. Mutation analyses were performed and two novel missense mutations were identified (C151Y) and (L273P) within exon 5 and exon 8, respectively. The 3D-structural characterization of these mutations provides evidence of defective folding of the mutant proteins, and likely alteration of the enzymatic activity. Phenotype variability was observed even among individuals sharing the same pathogenic mutation.
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PMID:Clinical and mutational investigations of tyrosinemia type II in Northern Tunisia: identification and structural characterization of two novel TAT mutations. 1657 53