Post by tummyache on Feb 15, 2012 17:03:29 GMT -5
This is only one section of the article titled “Fructose 1,6-Diphosphatase Deficiency” …the ending talks about new techniques in DIAGNOSIS..so be sure to look at the whole article and note 2 highlighted areas at the end. Hope for the future?
Fructose 1,6-Diphosphatase Deficiency
Authors: Robert J Ferry Jr, MD; Chief Editor: Bruce Buehler, MD more...
From: MEDSCAPE REFERENCE - Updated: Aug 12, 2010
emedicine.medscape.com/article/943882-overviewBackground
From the section “LABORATORY STUDIES”…..
• The most specific, minimally invasive, diagnostic test for fructose 1,6-diphosphatase (FDPase) deficiency is D-fructose challenge; however, this provocative test is dangerous and should be avoided during an acute crisis. In patients with FDPase deficiency, blood glucose levels fall below 60 mg/dL in response to D-fructose challenge, and the serum lactate levels rise (typically >2 standard deviations above the mean).
• Direct enzymatic assay of hepatic FDPase activity from hepatic specimens remains the most specific diagnostic test for this disorder. The assay is performed by a handful of reference laboratories (eg, Chen at Duke University).
• A prolonged fast can induce lactic acidosis with hypoglycemia in patients with FDPase deficiency as a result of impaired gluconeogenesis.
• Elevated urinary excretion of glycerol-3-phosphate appears to be specific to the disorder. The presence of glyceroluria at or shortly after the time of the metabolic crisis is a useful adjunct to confirm intact lipolytic pathways. However, hyperglyceroluria is not specific because it also can occur in patients with glycerol kinase deficiency.
• A controlled fasting study or D-fructose challenge under the supervision of a pediatric endocrinologist in the hospital setting permits recapitulation of the presentation to confirm the diagnosis. Less dangerous diagnostic techniques are available at few medical centers. However, simple peripheral blood specimens can be mailed to these centers for diagnosis while supportive care is provided to the patient.
• Glycerol challenge results in glyceroluria in patients with FDPase deficiency, although this result also occurs with disorders of glycerol metabolism (eg, glycerol kinase deficiency).
•[glow=red,2,300] In Japan, Iga et al reported a breakthrough for the screening of FDPase deficiency based on routine urine specimens.[6] Their work suggests that this method can rapidly determine FDPase deficiency in these patients either during a metabolic crisis or during the stable clinical condition. The technique combines modifications of the Matsumoto and Kuhara method of urinalysis with gas chromatography and mass spectrometry in the selected-ion monitoring mode. This landmark paper delineates the possibility of identifying many asymptomatic patients who may be undiagnosed, as well as patients misclassified with sudden infant death syndrome or Reye syndrome.
• Kikawa et al reported a minimally invasive diagnostic test using cultured lymphocytes.[7] This test is presently available only by contacting these investigators. [/glow]
Fructose 1,6-Diphosphatase Deficiency
Authors: Robert J Ferry Jr, MD; Chief Editor: Bruce Buehler, MD more...
From: MEDSCAPE REFERENCE - Updated: Aug 12, 2010
emedicine.medscape.com/article/943882-overviewBackground
From the section “LABORATORY STUDIES”…..
• The most specific, minimally invasive, diagnostic test for fructose 1,6-diphosphatase (FDPase) deficiency is D-fructose challenge; however, this provocative test is dangerous and should be avoided during an acute crisis. In patients with FDPase deficiency, blood glucose levels fall below 60 mg/dL in response to D-fructose challenge, and the serum lactate levels rise (typically >2 standard deviations above the mean).
• Direct enzymatic assay of hepatic FDPase activity from hepatic specimens remains the most specific diagnostic test for this disorder. The assay is performed by a handful of reference laboratories (eg, Chen at Duke University).
• A prolonged fast can induce lactic acidosis with hypoglycemia in patients with FDPase deficiency as a result of impaired gluconeogenesis.
• Elevated urinary excretion of glycerol-3-phosphate appears to be specific to the disorder. The presence of glyceroluria at or shortly after the time of the metabolic crisis is a useful adjunct to confirm intact lipolytic pathways. However, hyperglyceroluria is not specific because it also can occur in patients with glycerol kinase deficiency.
• A controlled fasting study or D-fructose challenge under the supervision of a pediatric endocrinologist in the hospital setting permits recapitulation of the presentation to confirm the diagnosis. Less dangerous diagnostic techniques are available at few medical centers. However, simple peripheral blood specimens can be mailed to these centers for diagnosis while supportive care is provided to the patient.
• Glycerol challenge results in glyceroluria in patients with FDPase deficiency, although this result also occurs with disorders of glycerol metabolism (eg, glycerol kinase deficiency).
•[glow=red,2,300] In Japan, Iga et al reported a breakthrough for the screening of FDPase deficiency based on routine urine specimens.[6] Their work suggests that this method can rapidly determine FDPase deficiency in these patients either during a metabolic crisis or during the stable clinical condition. The technique combines modifications of the Matsumoto and Kuhara method of urinalysis with gas chromatography and mass spectrometry in the selected-ion monitoring mode. This landmark paper delineates the possibility of identifying many asymptomatic patients who may be undiagnosed, as well as patients misclassified with sudden infant death syndrome or Reye syndrome.
• Kikawa et al reported a minimally invasive diagnostic test using cultured lymphocytes.[7] This test is presently available only by contacting these investigators. [/glow]
