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)

The genetic, clinical, and metabolic studies of two familial cases of Richner-Hanhart syndrome (type II hypertyrosinemia are described and the findings compared with other familial cases of palmo-plantar keratoderma. The clinical pictures are identical except that in the latter there are not ocular symptoms and the tyrosine levels are not raised. One of the two patients examined was treated with a diet low in tyrosine and phenylalanine with immediate improvement in clinical symptomatology and complete disappearance of the dendritic keratitis.
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PMID:Familial Richner-Hanhart syndrome: genetic, clinical, and metabolic studies. 624 Feb 14

Three children (6 eyes) with systemic tyrosinemia who presented with a diagnosis of herpes simplex keratitis are described. Two of the patients underwent extensive treatment for herpes simplex keratitis until their defects in tyrosine metabolism were discovered. All three children responded favorably to a low-tyrosine diet. These cases illustrate the typical corneal findings of the Richner-Hanhart syndrome (pseudodendritic keratitis, hyperkeratotic skin lesions of the palms and sole without mental retardation). The findings in these three patients were similar to those cases previously reported in the literature except none had mental retardation. The ophthalmologist confronted with a young child with bilateral dendritiform keratitis should request evaluation of the serum tyrosine levels.
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PMID:Pseudodendritic keratitis and systemic tyrosinemia. 645 71

The Richner-Hanhart syndrome corresponds to a tyrosine elevation in serum due to a defect in soluble tyrosine amino-transferase in liver cells. This new enzymopathy which is transmitted in an autosomal recessive mode is called oculo-cutaneous tyrosinosis. It is curable by a low diet in tyrosine and its precursors. The diagnosis has been clinically suggested in an 18 months old girl, by the association of punctate palmar and plantar keratosis, dendritic ulcerated keratitis, and mental retardation. The diagnosis was established by elevation of tyrosinemia up to 52 mg/100 ml associated with a high urinary elimination of tyrosine and phenylcetonic acid. Absence of anomaly in the metabolism of methionin and hepatorenal lesion is characteristic. The diagnosis was confirmed by the absence of soluble tyrosine aminotransferase in liver cells and by the effectiveness of the diet. The clinical keratosis corresponds histologically to a orthokeratotic hyperkeratosis. The keratinocytes show 2 types of anomalies ranged 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 images have been demonstrates anteriorly in the keratinocytes ant the corned; on the other hand, signs of mitochondrial anomaly 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 that the mitochondrial defect occurs outside this mechanism.
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PMID:[Changes in the keratinocytes in oculo-cutaneous tyrosinosis: Richner-Hanhart syndrome (author's transl)]. 723 83

Richner-Hanhart syndrome (Tyrosinemia Type II) is an autosomal recessive disorder of amino acid metabolism characterized by ocular changes, painful palmoplantar hyperkeratosis, and mental retardation. Serum tyrosine increases due to tyrosine aminotransferase deficiency resulting in the deposition of tyrosine crystals in the cornea and in corneal inflammation. Patients are often misdiagnosed as having herpes simplex keratitis. We report on a child who presented with bilateral keratitis secondary to Tyrosinemia Type II diagnosed as herpes simplex keratitis.
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PMID:Richner-Hanhart syndrome (tyrosinemia type II). Case report and literature review. 764 39

A 10-year-old boy with palmoplantar hyperkeratosis and keratitis was reported. His physical development was normal and mental development was lower limit. He had also convulsions with low grade fever several times, and his EEG showed paroxysmal discharges. The plasma levels of phenylalanine and tyrosine were 5 to 10 times higher than those of controls. Tyrosinemia II was diagnosed on the low level of cytosol tyrosine aminotransferase in biopsied liver. The cases of tyrosinemia II were reviewed on the symptoms of the central nervous system. Two of twelve cases had convulsions. Adult cases demonstrated nystagmus, tremor, ataxia, and convulsion. Hyperkeratosis and corneal lesions were characteristic in symptoms of tyrosinemia II, but attention should be paid to the symptoms of the central nervous system.
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PMID:[A case of tyrosinemia type II with convulsion and EEG abnormality]. 826 Feb 11

Richner-Hanhart syndrome, also called oculo-cutaneous tyrosinosis type II, is a recessive autosomal genodermatosis consecutive to a disorder of tyrosine metabolism. It presents as a varying association of palmo-plantar keratosis, bilateral keratitis and mental retardation. The authors report a new case which is atypical in that palmoplantar keratosis made a late appearance. The diagnosis was confirmed by the presence of hypertyrosinaemia, hypertyrosinuria and urinary excretion of phenolic acids, and the absence of hepato-renal lesion. Needle biopsy of the liver, which demonstrates the deficiency of soluble cytosolic tyrosine aminotransferase, is not indispensable to the diagnosis and was not performed in our patient. Treatment consisted of a dietary measure: a controlled phenylalanine and tyrosine intake to obtain a tyrosinaemia below 10 mg/100 ml. This resulted in a favourable and durable course of the oculo-cutaneous lesions. In case of isolated skin lesion, retinoids can be prescribed either alone of combined with a diet, making it less strict.
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PMID:[Oculocutaneous type II tyrosinosis]. 836 6

Tyrosinemia type II (Richner-Hanhart syndrome, RHS) is a disorder 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). We have previously described one deletion and six different point mutations in four RHS patients. We have now analyzed the TAT genes in a further seven unrelated RHS families from Italy, France, the United Kingdom, and the United States. We have established PCR conditions for the amplification of all twelve TAT exons and have screened the products for mutations by direct sequence analysis or by first performing single-strand conformation polymorphism analysis. We have thus identified the presumably pathological mutations in eight RHS alleles, including two nonsense mutations (R57X, E411X) and four amino acid substitutions (R119W, L201R, R433Q, R433W). Only the R57X mutation, which was found in one Scottish and two Italian families, has been previously reported in another Italian family. Haplotype analysis indicates that this mutation, which involves a CpG dinucleotide hot spot, has a common origin in the three Italian families but arose independently in the Scottish family. Two polymorphisms have also been detected, viz., a protein polymorphism, P15S, and a silent substitution S103S (TCG-->TCA). Expression of R433Q and R433W demonstrate reduced activity of the mutant proteins. In all, twelve different TAT gene mutations have now been identified in tyrosinemia type II.
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PMID:Novel and recurrent tyrosine aminotransferase gene mutations in tyrosinemia type II. 954 43

Emerging evidence indicates that intracellular signaling cascades mediate entry of pathogenic adenoviruses into target host cells as well as some of the undesirable inflammatory responses to adenoviral gene vectors. We found that Ad19 infection of cultured human corneal fibroblasts induced IL-8 gene transcription independently of IL-1beta, TNF-alpha, and viral gene expression, suggesting that intracellular signaling events might mediate early inflammatory events in adenovirus keratitis. Heat but not UV light inactivation of the virus abrogated the effect of infection on IL-8 mRNA and protein levels, consistent with a viral binding-mediated mechanism. The tyrosine kinase inhibitor herbimycin blocked Ad19-induced IL-8 expression. Western blot analysis revealed tyrosine phosphorylation of the functionally related kinases c-Src and extracellular signal-regulated kinase (ERK) 1/2 in corneal fibroblasts within 15 min after infection. Respective inhibitors of these kinases, PP2 and PD98059, also blocked Ad19-induced IL-8 mRNA and protein expression. Application of inhibitors to Src and ERK kinase assays suggested an upstream relationship of c-Src to ERK. Finally, DNA microarray studies performed 1 h after Ad19 or mock infection of corneal fibroblasts in the presence or absence of the Src-specific inhibitor PP2 confirmed a relationship between c-Src and IL-8 expression in Ad19-infected corneal cells. c-Src may act as a global regulator of early proinflammatory host responses to Ad19 infection of the human cornea.
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PMID:Corneal IL-8 expression following adenovirus infection is mediated by c-Src activation in human corneal fibroblasts. 1279 55

Tyrosinemia type II or Richner-Hanhart syndrome is a rare hereditary disease characterized by the association of pseudoherpetiform corneal ulcerations and palmoplantar hyperkeratosis. We report the case of a 12 year-old young man presenting a superficial punctate keratitis and a corneal dystrophy in both eyes, associated with a palmoplantar hyperkeratosis. The dosage of the serum level of tyrosine is meaningfully raised to 1236 micromol/l. A dietary treatment restraining tyrosine and phenylalanine is started with favorable results after an evolution of 6 months. Tyrosinemia type II is an autosomal recessive disease, due to an enzymatic deficit in tyrosine aminotransferase. The diagnosis is based on the clinic and high level of serum and urinary tyrosine as well as of its urinary metabolites. This disease must be suspected in all cases of dentritic keratitis not reacting on the antiviral treatment, and more especially if it is associated with cutaneous lesions such as palmo-plantar keratosis.
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PMID:[Tyrosinemia type II. Case report]. 1605 Apr 20

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


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