MCQsOnline - Online Collection of MCQs of Medical PG Entrance Exams.

MCQ stands for Multiple Choice Questions sometimes called as Objective type questions. Here we discuss the Old Question Papers, High Yield Points and Strategies with respect to the Indian Medical Post Graduate PG Entrance Exams like AIIMS,AIPG, JIPMER, CMC Vellore, PGI Chandigarh, UPSC, TNPSC, State PG Exams like Tamil Nadu PG (TN PG), Delhi PG, UPPG, Tamilnadu PG (TNPG), Karnataka PG, MAHE, COMED-K etc.

Target PG

PG Preparation

Related Portals

Search This Site

If you cannot locate what you want to find, please search using the box given below

Monday, December 15, 2008

Von Gierke disease - A child presents with Massive hepatomegaly, hypoglycemia, and there is no improvement with Glucagon.

Question 30
A child presents with Massive hepatomegaly, hypoglycemia, and there is no improvement with Glucagon. The probable diagnosis is
a.       Von Gierke disease
b.      Mcardle
c.       Cori
d.      Forbe
Answer
a) Von Gierke
Reference
Harper 27th Edition Pages 166, 308, table 19.2
Table 73.1 Nelson 15th Edition Table 350-1 Harrison 15th Edition
QTDF
Most Books
Quality
Spotter
Status
Repeat
Discussion
Glycogen storage disease type I or von Gierke's disease, is the most common of the glycogen storage diseases. This genetic disease results from deficiency of the enzyme glucose-6-phosphatase. This deficiency impairs the ability of the liver to produce free glucose from glycogen and from gluconeogenesis. Since these are the two principal metabolic mechanisms by which the liver supplies glucose to the rest of the body during periods of fasting, it causes severe hypoglycemia. Reduced glycogen breakdown results in increased glycogen storage in liver and kidneys, causing enlargement of both. Both organs function normally in childhood but are susceptible to a variety of problems in the adult years. Other metabolic derangements include lactic acidosis and hyperlipidemia. Frequent or continuous feedings of cornstarch or other carbohydrates are the principal treatment. Other therapeutic measures may be needed for associated problems.
Explanation
Self Explanatory
Comments
GSD No
Name
Enzyme Affected
Tissue Distribution of
Excessive Glycogen and
Enzyme Deficiency
Clinical Symptoms
and Signs
Comments
GSD Ia
Von Gierke disease,
Glucose-6-phosphatase
Liver, kidney, intestine; frequent intranuclear glycogen seen in
  these organs not diagnostic; continuous nighttime feeding by
  tube and pump may alleviate clinical symptoms; portacaval
  shunt risky and clinically disappointing; treatment with
  phenytoin or phenobarbital ineffective
Enlarged liver and kidneys; "doll face," stunted growth,
  normal mental development; tendency to hypoglycemia, lactic
  acidosis, hyperlipidemia, hyperuric acidemia, gout, bleeding;
  IV* galactose or fructose not converted to glucose (caution:
  these tests may precipitate acidosis); abortive or no rise in
  blood glucose after SC† epinephrine or IV glucagon; normal
  urinary catecholamines; prognosis fair to good
hepatorenal glycogenosis; no
  involvement of skeletal or cardiac muscle, or of leukocytes or
  cultured skin fibroblasts (glucose-6-phosphatase not normally
  present in these tissues)
  GSD Ib
In vitro activity of glucose-6-phosphatase is
    normal, but translocase is deficient
 
Activity of glucose-6-phosphatase is normal in frozen liver
  homogenate but is not demonstrable in isotonic homogenate
  of fresh liver tissue that has never been frozen
Symptoms are as those of GSD Ia; in addition, frequent
  neutropenia
Transport defect for glucose-6-phosphate at microsomal
  membrane
GSD Ic
In vitro activity of glucose-6-phosphatase
    can be demonstrated
Activity of glucose-6-phosphatase is normal in frozen liver
  homogenate but is deficient in isotonic homogenate of fresh
  liver tissue that has never been frozen
The patient, an 11-yr–old girl, had hepatomegaly, brittle
  diabetes, frequent hypoglycemia
Transport defect for inorganic phosphate at microsomal
  membrane
Tips
The hypoglycemia of GSD I is termed "fasting", or "post-absorptive", meaning that it occurs after completion of digestion of a meal-- usually about 4 hours later. This inability to maintain adequate blood glucose levels during fasting results from the combined impairment of both glycogenolysis and gluconeogenesis. Fasting hypoglycemia is often the most significant problem in GSD I, and typically the problem that leads to the diagnosis. Chronic hypoglycemia produces secondary metabolic adaptations, including chronically low insulin levels and high levels of glucagon and cortisol.

No comments:

Post a Comment