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drmmanish@yahoo.co.in
Joined: 05 Mar 2008
Posts: 42
Location: UK
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 Posted: Fri Sep 05, 2008 7:25 am Post subject: Glucose 6 phosphate dehydrogenase (G6PD) |
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G6PD: neonatal dehydrogenase deficiency
G6PD: neonatal cyanosis
g6pd is an enzyme defect that causes breakdown of rbcs. Does not in itself cause cyanosis and there is no entitity called neonatal dehydrogenase deficiency unless they mean g6pd in the neonate as it is g6p dehydrogenase deficiency.
I think the inheritance is x linked recessive. Probably the answer is false
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Nick Raine-Fenning
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| Posted: Sat Sep 06, 2008 3:51 pm Post subject: |
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| docsubhi wrote: | agreed manish
the invigilator made an ammendment in the exam as it was a typing error with G6PD - and changed to neonatal cyanosis as it read
glucose 6 phosphate = neonatal cyanosis dehydrogenase (?deficiency) |
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Nick Raine-Fenning
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| Posted: Sun Sep 07, 2008 10:59 am Post subject: |
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Regardless of the quesiton let's do some G6PD revision.
I'll start you off:
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Glucose-6-phosphate dehydrogenase deficiency (G6PD):
? is the most common human enzyme defect
? is inherited as an X-linked dominant condition
? most individuals with G6PD deficiency are asymptomatic.
? is characterised by abnormally high levels of glucose-6-phosphate dehydrogenase
? often presents with jaundice in response infection or exposure to certain medications or chemicals
? is associated with a Coombs positive haemolytic anaemia
? is associated with favism
? may present with prolonged neonatal jaundice
? has five genetic variants all of which reflect the degree of deficiency
? confers protection against malaria
? may be treated by splenectomy
? sufferers should be given folic acid
Last edited by Nick Raine-Fenning on Sun Sep 07, 2008 7:28 pm; edited 1 time in total |
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Nick Raine-Fenning
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| Posted: Sun Sep 07, 2008 11:00 am Post subject: |
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Acute haemolysis in patients with glucose-6-phosphate dehydrogenase deficiency (G6PD) may be precipitated by:
? diabetic ketoacidosis
? acute renal failure
? upper respiratory tract infection
? anti-malarial drugs
? sulfonamides
? methylene blue
? aspirin
? nitrofurantoin
? henna
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Nick Raine-Fenning
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Posts: 1852
Location: Nottingham
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| Posted: Sun Sep 07, 2008 7:28 pm Post subject: |
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Acute haemolysis in patients with glucose-6-phosphate dehydrogenase deficiency (G6PD) is characterised by:
? The presence of Heinz bodies
? Increased lactate dehydrogenase (LDH) which correlates with disease severity
? An increased haptoglobin
? A positive direct Coombs test
? A positive Beutler fluorescent spot test |
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rpwalavalkar
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Joined: 20 Jul 2006
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| Posted: Mon Sep 08, 2008 6:12 am Post subject: |
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Nick,
these are a killer.  
r
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Dr Miss. Raj Walavalkar MBBS MRCOG
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cpeedahsa
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| Posted: Tue Sep 09, 2008 3:06 pm Post subject: |
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| Nick Raine-Fenning wrote: | Glucose-6-phosphate dehydrogenase deficiency (G6PD):
? is the most common human enzyme defect |
True
affects 400 million people worldwide
G6PD- first enzyme in the hexose monophosphate pathway (HMP) pathway.
In RBC not oxidatively stressed- 90% glucose metabolised along the anaerobic Embden-Meyerhof pathway and 10% metabolised aerobically along HMP pathway. In HMP pathway, G6PD forms most of the reduced NADPH in cells necessary for the reactions of various biosynthetic pathways, the stability of catalase and the regeneration of reduced glutathione (GSH) from the oxidised glutathione (GSSG).
The reduced form of NADPH, catalase and GSH are the main antioxidants of cells.
G6PD =source of reducing power in the form of sulfhydryl buffers that maintains the integrity of protein and lipid sulfhydryl groups and aids in the detoxification of free radicals and peroxides
Last edited by cpeedahsa on Tue Sep 09, 2008 3:35 pm; edited 1 time in total |
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cpeedahsa
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| Posted: Tue Sep 09, 2008 3:09 pm Post subject: |
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| Nick Raine-Fenning wrote: | | ? is inherited as an X-linked dominant condition |
False - x-linked recessive disorder |
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cpeedahsa
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| Posted: Tue Sep 09, 2008 3:13 pm Post subject: |
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| Nick Raine-Fenning wrote: | | most individuals with G6PD deficiency are asymptomatic. |
True
Most asymptomatic. Some - history of neonatal jaundice, often requiring exchange transfusion. A history of infection or drug-induced hemolysis is also common. Gallstones may be a prominent feature. Splenomegaly may be present. |
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cpeedahsa
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| Posted: Tue Sep 09, 2008 3:18 pm Post subject: |
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| Nick Raine-Fenning wrote: | ? is characterised by abnormally high levels of glucose-6-phosphate dehydrogenase
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Because of the word characterised in the question I would go with False
but this is something that is important to remember
The five classes of G-6-PD deficiency include low, normal, or increased levels of the enzyme.
The World Health Organisation classifies G6PD genetic variants into five classes, three of which are deficiency states.
Severe deficiency (<10% activity) with chronic (nonspherocytic) hemolytic anemia
Severe deficiency (<10% activity), with intermittent hemolysis
Mild deficiency (10-60% activity), hemolysis with stressors only
Non-deficient variant, no clinical sequelae
Increased enzyme activity, no clinical sequelae
Last edited by cpeedahsa on Tue Sep 09, 2008 3:45 pm; edited 2 times in total |
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cpeedahsa
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| Posted: Tue Sep 09, 2008 3:27 pm Post subject: |
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| Nick Raine-Fenning wrote: | often presents with jaundice in response infection or exposure to certain medications or chemicals
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True |
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cpeedahsa
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| Posted: Tue Sep 09, 2008 3:28 pm Post subject: |
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| Nick Raine-Fenning wrote: | is associated with a Coombs positive haemolytic anaemia
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False
this should be negative, as hemolysis in G6PD is not immune-mediated |
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cpeedahsa
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| Posted: Tue Sep 09, 2008 3:43 pm Post subject: |
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| Nick Raine-Fenning wrote: | may present with prolonged neonatal jaundice
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True |
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cpeedahsa
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| Posted: Tue Sep 09, 2008 3:44 pm Post subject: |
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| Nick Raine-Fenning wrote: | is associated with favism
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true
Favism occurs only in the Mediterranean variety of G-6-PD deficiency |
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cpeedahsa
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| Posted: Tue Sep 09, 2008 3:46 pm Post subject: |
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| Nick Raine-Fenning wrote: | has five genetic variants all of which reflect the degree of deficiency
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True
as explained above |
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cpeedahsa
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| Posted: Tue Sep 09, 2008 3:49 pm Post subject: |
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| Nick Raine-Fenning wrote: | confers protection against malaria
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TrueIt confers protection against malaria in particular the form of malaria caused by Plasmodium falciparum. |
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cpeedahsa
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| Posted: Tue Sep 09, 2008 3:51 pm Post subject: |
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| Nick Raine-Fenning wrote: | | may be treated by splenectomy |
True |
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cpeedahsa
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| Posted: Tue Sep 09, 2008 3:52 pm Post subject: |
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| Nick Raine-Fenning wrote: | | sufferers should be given folic acid |
TRUE
Folic acid should be used in any disorder featuring a high red cell turnover. |
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Nick Raine-Fenning
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| Posted: Tue Sep 09, 2008 6:03 pm Post subject: |
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Well done - all correct except 2 and these you actually explained correctly but gave the wrong answer!!
They relate to the sub-groups and the WHO classification.
G6PD levels are 'charactersitically' low
and
not all types are associated with low levels (they are normal in groups 4 and 5)
N |
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cpeedahsa
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| Posted: Tue Sep 09, 2008 8:27 pm Post subject: |
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| Nick Raine-Fenning wrote: | Well done - all correct except 2 and these you actually explained correctly but gave the wrong answer!!
They relate to the sub-groups and the WHO classification.
G6PD levels are 'charactersitically' low
and
not all types are associated with low levels (they are normal in groups 4 and 5)
N |
G6PD levels are 'charactersitically' low -- so the answer to that question | Quote: | | is characterised by abnormally high levels of glucose-6-phosphate dehydrogenase |
is False as mentioned in my post ... right?
Or am I missing something
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