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)

A deficiency of hepatic tyrosine aminotransferase in humans is responsible for a syndrome of keratitis, palmar and plantar erosions and hyperkeratosis and mental retardation. Serum tyrosine increases due to the enzymatic deficiency leads to the deposition of tyrosine crystals in the eye and cornea. This deposition and possible lysosomal activation leads to inflammation in the cornea and the skin. The syndrome can be reproduced in animals who are fed a high tyrosine diet. The interaction of tyrosine crystals with membrane-bound particles can be studied in vitro with lysosomes and erythrocytes.
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PMID:Molecular biology and molecular pathology of a newly described molecular disease--tyrosinemia II (the Richner-Hanhart syndrome). 2 31

Tyrosine-induced eye and skin lesions in man are an autosomal, recessive, inherited syndrome associated with tyrosinemia, tyrosinuria, and increased urinary excretion of tyrosine metabolites. Patients have mild to severe keratitis and erosive and hyperkeratotic lesions on the palms and soles. The degree of involvement was variable in the small number of patients studied. Mental retardation is frequently a part of the syndrome. A low-tyrosine low-phenylalanine diet lowers blood tyrosine level and leads to healing of the skin and eye lesions. Early dietary treatment may prevent mental retardation.
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PMID:Tyrosine-induced eye and skin lesions. A treatable genetic disease. 13 41

A boy of 3 2/12 years of age with Richner-Hanhart syndrome (plantar and palmar keratosis and chronic keratitis) was found to have hypertyrosinemia and to excrete the hydroxyacids derived from tyrosine. A diet poor in phenylalanine and tyrosine cured the skin and corneal lesions. Clinical and biochemical observations are reported.
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PMID:Tyrosinemia without liver or renal damage with plantar and palmar keratosis and keratitis (hypertyrosinemia type II). 15 8

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 (Richner-Hanhart syndrome, RHS) is a disease of autosomal recessive inheritance characterized by keratitis, palmoplantar hyperkeratosis, mental retardation, and elevated blood tyrosine levels. The disease results from deficiency in hepatic tyrosine aminotransferase (TAT; L-tyrosine:2-oxoglutarate aminotransferase, EC 2.6.1.5), a 454-amino acid protein encoded by a gene with 12 exons. To identify the causative mutations in five TAT alleles cloned from three RHS patients, chimeric genes constructed from normal and mutant TAT alleles were tested in directing TAT activity in a transient expression assay. DNA sequence analysis of the regions identified as nonfunctional revealed six different point mutations. Three RHS alleles have nonsense mutations at codons 57, 223, and 417, respectively. One "complex" RHS allele carries a GT----GG splice donor mutation in intron 8 together with a Gly----Val substitution at amino acid 362. A new splice acceptor site in intron 2 of the fifth RHS allele leads to a shift in reading frame.
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PMID:Point mutations in the tyrosine aminotransferase gene in tyrosinemia type II. 135 62

Corneal inflammation with subsequent scarring and blindness occurs in the inherited human metabolic disease tyrosinemia type II, yet putative inflammatory mediators in this disorder and in the avascular cornea in general are poorly defined. In a Tyr-fed rat model of tyrosinemia type II, intracellular crystals, presumably Tyr, are hypothesized to be responsible for the increased lysosomal activity observed in corneal epithelial lesions. Because polymorphonuclear leukocytes (PMNs) are seen only at the site of these lesions, we used this model to study humoral mediators released from Tyr-fed rat corneal organ cultures. Only Tyr-fed rats developed stromal edema and linear granular opacities in gray edematous corneal epithelium, compatible with a noninfectious keratitis. Electron micrographs confirmed epithelial edema and showed focal epithelial necrosis with PMN invasion of the stroma. Only Tyr-fed rat corneal culture supernatants contained chemotactic activity that was heat labile and moderately trypsin sensitive. Four peaks with varying amounts of chemotactic activity were found on Sephadex G-75 chromatography. Although the identity of these peaks of activity has not yet been established, we suggest that they may be responsible for the PMN infiltration observed in this model of corneal inflammation.
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PMID:Corneal organ cultures in tyrosinemia release chemotactic factors. 258 Sep 25

The authors report the cases of two unrelated children 16 and 5 years of age respectively, affected with hypertyrosinaemia type II. This condition is characterized by palmo-plantar hyperkeratosis associated with a herpetiform keratitis. The diagnosis is based on the finding of hypertyrosinaemia and hypertyrosyluria, and may be confirmed by their biopsy findings of a cytoplasmic tyrosine amino-transferase deficiency. It is a hereditary autosomal recessive disease. A low phenylalanine and tyrosine diet produced a spectacular improvement but the ocular complications could have been avoided by an earlier diagnosis.
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PMID:[Palmoplantar keratosis associated with keratitis: hereditary hypertyrosinemia treated by diet]. 294 Sep 55

Type II tyrosinemia (Richner-Hanhart syndrome) is a familial aminoacid disorder, clinically characterized by ocular changes (keratitis), palmo-plantar hyperkeratosis, no constant mental changes with mental deterioration, abnormal urinary excretion and high serum tyrosine level in consequence of the absence of tyrosine-aminotransferase. Almost 20 families have been described in the literature of which 50% are of Italian origin, suggesting that this disorder is particularly frequent in our country. We report a family with 2 affected members with typical clinical and biochemical findings (keratitis, palmo-plantar hyperkeratosis, abnormal urinary and serum tyrosine concentrations), not suffering from mental retardation. Clinical symptoms completely disappeared after the decrease of urinary and serum tyrosine levels following a tyrosine- and phenylalanine-free diet. These cases are compared with those reported in literature, and the usefulness of diet for the improvement of clinical and metabolic symptoms is discussed.
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PMID:The effect of diet on the ophthalmological, clinical and biochemical aspects of Richner-Hanhart syndrome: a morphological ultrastructural study of the cornea and the conjunctiva. 365 59

The Richner-Hanhart syndrome corresponds to a tyrosine elevation in serum due to deficit in soluble tyrosine aminotransferase in liver cells. This new enzymopathy which is transmitted in an autosomal recessive mode is called oculocutaneous tyrosinosis. It is curable by a poor diet in tyrosine and its precursors. The diagnosis has been invoked in a 18 months old girl, on the association of punctuate palmar and plantar keratosis, dentritic ulcerated keratitis, and mental retardation. The diagnosis is confirmed by elevation of tyrosinemia to 52 mgs/100 mls associated with a high urinary elimination of tyrosine and plenylcetonic acid. Absences of anomaly in the metabolism of methionin and hepatorenal absence of disturbance of hepatorenal system is characteristic. The keratosis accompany orthokeratotic hyperkeratosis. The keratinocytes show 2 types of anomaly ranged in strates in the epiderm. Intracytoplasmic vacuoles which include or lead to pseudomyelinic formations extend progressively from the mitochondrial alterations in the epidemial basal layers. Bulky polyhedral electron dense particles are found in the cytoplasm of the superficial keratinocytes. Most of these aspects have been demonstrated anteriorly in the keratinocytes and the cornea; on the other hand, signs of mitochondrial sulferance had not been observed. The genesis of these cellular alterations based on the liberation of lysosomial enzymes by the action of crystals of tyrosine has been suggested by Goldsmith from experimental facts. However, it seems the mitochondrial defect occurs outside this mechanism.
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PMID:[Oculo-cutaneous tyrosinosis (Richner-Hanhart syndrome). Histo-pathological study of a case]. 611 39

An 11-year-old girl with keratitis and plantar keratosis had tyrosinemia. The concentration of tyrosine in the plasma was 16.5 mg/dL. Dietary intake of phenylalanine and tyrosine was systematically varied, and the plasma concentrations of tyrosine and nitrogen balance were studied. It was necessary to achieve a total intake of phenylalanine and tyrosine less than 100 mg/kg/day to obtain plasma concentrations of tyrosine of less than 10 mg/dL. After dietary therapy was started, the keratitis resolved promptly, and the patient remained asymptomatic during a period of 16 months in which the mean plasma concentration of tyrosine was 11.1 mg/dL. The dietary management of a child at this age presents a different problem from that of a young infant. It can be successfully pursued at home, as well as in the carefully regulated environment of a clinical research center.
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PMID:Dietary management of oculocutaneous tyrosinemia in an 11-year-old child. 622 30


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