1/3. carnitine-deficient myopathy as a presentation of tyrosinemia type I.carnitine deficiency secondary to renal Fanconi's tubulopathy has been described in only a few inborn errors of metabolism: cystinosis, galactosemia, and Fanconi-Bieckel syndrome. We report a 27-month-old infant who presented with a sudden change in gait owing to proximal muscle weakness. The laboratory evaluation showed carnitine deficiency associated with Fanconi's tubulopathy. Eventually, tyrosinemia type I was diagnosed. carnitine deficiency can contribute to the clinical picture of hepatorenal tyrosinemia and should therefore be evaluated and treated.- - - - - - - - - - ranking = 1keywords = hepatorenal (Clic here for more details about this article) |
2/3. Newborn screening for hepatorenal tyrosinemia: Tandem mass spectrometric quantification of succinylacetone.BACKGROUND: False-positive and false-negative results occur in current newborn-screening programs for hepatorenal tyrosinemia, which measure tyrosine concentrations in blood spots, sometimes in combination with other metabolites, including succinylacetone. We present our experience with a newly described method for succinylacetone quantification in routine newborn screening. methods: Succinylacetone was extracted from blood spots that had already been extracted with absolute methanol for acylcarnitine and amino acid analysis. The solvent was acetonitrile-water (80:20 by volume) containing formic acid, hydrazine hydrate, and 100 nmol/L 5,7-dioxooctanoic acid as internal standard. Analysis was performed by tandem mass spectrometry in a separate run. RESULTS: Of 61,344 samples, 99.6% had succinylacetone concentrations < or =5 micromol/L. With a cutoff of 10 micromol/L, no false-positive results were obtained. In 2 patients, the succinylacetone concentrations in the dried blood spots from the 36th and 56th hours of life were 152 and 271 micromol/L, respectively, and the tyrosine concentrations were 54 and 129 micromol/L. Hepatorenal tyrosinemia was subsequently confirmed in both patients. Retrospective analysis of the neonatal screening samples of 2 additional known patients revealed increased succinylacetone concentrations of 46 and 169 micromol/L, respectively. CONCLUSIONS: Tandem mass spectrometric quantification directly from residual blood spots is a useful method for the early detection of hepatorenal tyrosinemia in newborn-screening programs.- - - - - - - - - - ranking = 6keywords = hepatorenal (Clic here for more details about this article) |
3/3. Oculocutaneous tyrosinaemia or tyrosinaemia type 2: a case report.Oculo-cutaneous tyrosinaemia type II is an autosomal recessive disease due to an abnormality of tyrosine metabolism, probably because of a deficiency of cytoplasmic tyrosine aminotransferase. It presents as a varying association of focal palmoplantar keratosis, bilateral keratitis and mental retardation. Herein, we report an 8-year-old boy with palmoplantar hyperkeratosis with peripheral oozing and dendritic keratitis appearing after the skin lesions. There was no mental deterioration despite the long delay in diagnosis of the disorder. The diagnosis was confirmed by the presence of hypertyrosinaemia and the absence of hepatorenal lesion. The child exhibited a remarkable degree of improvement in the hyperkeratotic lesions and keratitis after the dietary modifications were instituted. In conclusion, chronic focal bullous palmoplantar hyperkeratosis along with keratitis should alert the clinician to screen for abnormal serum and/or urine tyrosine level. awareness of the presenting signs and symptoms may speed up the diagnosis and initiation of a tyrosine and phenylalanine-restricted diet that is most efficient in improving the symptoms and preventing visual and cognitive impairment.- - - - - - - - - - ranking = 1keywords = hepatorenal (Clic here for more details about this article) |