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When do we speak about galactos a em ia ?

Lactose. ( disaccharide ). When do we speak about galactos a em ia ?. at the root of the intestinal villi ( lactase (β galactosidase ) enzyme. + H 2 O. hydrolysis. Galactose Glucose (D). monosaccharide. monosaccharide. inhibitid. Glucose. monosaccharide.

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When do we speak about galactos a em ia ?

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  1. Lactose ( disaccharide) When dowe speak about galactosaemia? at the root of the intestinal villi (lactase (β galactosidase ) enzyme + H2O hydrolysis Galactose Glucose (D) monosaccharide monosaccharide inhibitid Glucose monosaccharide

  2. galactosealdosereductase galactitol galactokinase galactose-1-P gal.-1-P uridyl transferase. UDP galactose UDP gal.-4-epimerase UDP glucose UDPG pyrophosporilase glucose-1-P The process of conversion Total galactose

  3. THE PHOSPHORYLATION glucose galactose GLUT GALT impermeable cytosol The glucose-6-phosphate and the galactose-1-phosphate fall into an ambush in the cell. cytosol

  4. „Microbiological newbornscreening” Determination ofgalactosaemia : based on Guthrie microbiological metabolic inhibition method Principle:the blood-soakedfilter paper spots are placed on agarose medium witch contains galactose sensitive mutant E.coli (W5) strain

  5. Weidemann test: galactose over 20 mg % • Principle: The galactose – dehydrogenase • ( Gal-DH ) enzyme transfers H+ • from galactose to NAD, to form • fluorescent NADH • Control (mg % ) Sample • 20 25 30 35 40

  6. Interfering factors: False-positive result: 1. if antibiotic was given to the newborn which inhibits the growth of E-coli 2. any contamination which gives a clear zone around the disk False-negative result: 1. if the blood sample was taken before breast feeding was started 2. if the filter paper was not blood soaked properly 3. if the baby was transfused

  7. Total Galactose Screening Assay / galactose and galactose-1- phosphate / R &D Diagnostics Ltd Greece alkaline phosphatase galactose-1- phosphate Galactose galactose dehydrogenase Galactose + NAD+H2O Galaktono (1,4) lakton + NADH+ + H+ diaphorase NADH + NBT ( yellow ) NBTH ( violet ) + NAD / nitroblu-terazolium / / formazan /

  8. screening plate of galactosaemia

  9. Beutler probe: determination the deficit of galactose-1-phosphate – uridil- transferase ( G-1-PUT ) enzyme to confirm the diagnosis of classical galactosaemia Samples: heparinised total blood collected into gas capillary and a healthy control blood which is collected, transported, stored, and measured under the same conditions

  10. Principle: In the presence of G-1-PUT the NADP is reduced forming fluorescent NADPH blood + galactose-1-phosphate + NADP 30‘ 60‘ 90‘ 120‘ Control: Sample:

  11. Time ( minute ) 0 30 60 90 120 Control Galaktosaemia . heterozygote Galaktosaemia classic Duarte variant Duarte variantheterozygote

  12. Detection of Galactose-1-phosphate uridil-transferase /GALT/ enzyme GALT GAL-1-P + UDPGGalactose-1-phosphate uridil-transferase G-1-P + UDP-GAL PGM G-1-P phosphoglucomutase G-6-P G-6-PD G-6-P + NADPglucose-6-phosphate dehydrogenase6-PGA + NADPH+ 6-PGD 6-PGA + NADP6-fphosphogluconate dehydrogenaseR-5-P + NADPH+

  13. Results GALT enzyme aktivity : Normal : > 3,8 U/gHb Transitional: 2,9 -3,8 U/gHb Abnormal: < 2, 9U/gHb

  14. Screened galactosaemic cases

  15. Most common point mutations G-1-PUTransferase Galactokinase GALT GalK1 GalK2 9p1317q24 15q21.1 Classical Duarte Q188R G1391A S142I G171V K285N N314D G148C P28T

  16. Newborn screening of galactosaemia in Europe

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