Diagnosis

Now Serving: The Cheese

- hope this is not to cheesy for you

To sum up on the topic of McArdle Disease, we will be talking about how the diagnosis step taken.

Before that, let's have a overall view of how glucose is broken down in the cells when it undergoes anaerobic glycolysis.

The Diagnosis

Diagnosis of Glycogen Storage Disease Type V will commence if the doctor notices that patient possesses multiple of the symptoms indicated for this disease. Firstly, laboratory tests will be carried out. A muscle biopsy will be carried out to find out if there is an absence of myophosphorylase found in muscle fibers. A microscope can also be used to view acid-Schiff stained glycogen in some cases.

Genetic sequencing of the PYGM gene, which is responsible for the coding of myophosphorylase, may be done to determine if there is indeed a mutation in the gene and hence determining the presence of McArdle's disease. This testing is preferred due to its less invasive nature as compared to conducting a muscle biopsy.

- one mouthwatering burger from our restaurant

That's all from us! We hope that you have enjoy the meal throughout the whole course and learn more about the facts of McArdle Disease.

This will be our last time posting as our restaurant is moving out of Ngee Ann Polytechnic, School of Life Science & Chemical Technology, Blk83 B1-01 with effect of today 2359. :)


http://www.patient.co.uk/doctor/mcardles-disease-glycogen-storage-disease-type-v
http://en.wikipedia.org/wiki/Glycogen_storage_disease_type_V#Diagnosis

Biochemistry

Now Serving: The Lettuce

- the crunch you get from fresh lettuce

We are back from the Common Test week and will continue update this space! :D

Let's start off with the Biochemistry of Glycogen

Glycogen is principally found in muscle and liver cells, where it is stored as an energy source readily converted into glucose whenever our body requires energy. When muscle cells require energy, glycogen will be converted to ATP.

As seen from the picture, glycogen is actually comprised of linked alpha-D-glucose monomers that form linkages by either alpha-1,4 or alpha-1,6 linkages.

Glycogen Breakdown

Glycogen is broken down by glycogen phosphorylase. The reaction is non hydrolytic as water molecules are not produced upon the breakdown. Glycogen phosphorylase combines inorganic phosphate with the non reducing terminal glucose residue to form glucose-1-phosphate. 

Disease

When someone actually contracts McArdle's Disease, they're ability to synthesize glycogen phosphorylase is not impaired, but due to mutations in the gene coding for Myophosphorylase, they are unable to execute their normal function of breaking down glycogen into glucose, as such, mucles are deprived of glucose with is then converted to ATP via other metabolic pathways, which thus leads to accelerated muscle fatigue and glycogen remains accumulated in muscle tissues, hence the name Glycogen Storage Disease.

References
https://www.uic.edu/classes/phar/phar332/Clinical_Cases/carbo%20metab%20cases/glycogen%20metab/Glycogen%20biochemistry.htm

http://medicinembbs.blogspot.sg/2011/02/genetic-diseases.html

http://www.nlm.nih.gov/medlineplus/ency/article/000329.htm

http://en.m.wikipedia.org/wiki/Glycogen_storage_disease_type_V

http://mcardlesdisease.org/

http://www.patient.co.uk/doctor/mcardles-disease-glycogen-storage-disease-type-v

Symptoms of McArdle Disease

Now Serving: The Patties 

- the sizzle of the patty juice 

As mentioned in the previous post "Causes of McArdle Disease", it is mentioned that due to a nonsense or missense mutation in the PYGM gene that is coding for myophosphorylase. As a result, muscle cells cannot produce enough energy, so muscles become easily fatigued.

Phosphorylase deficiency causes exercise intolerance, such as cramps, muscle pain and weakness, shortly after beginning exercise.

A person with this disorder may tolerate light-to-moderate exercise such as walking on level ground, but strenuous exercise usually will bring on symptoms quickly. Resting may lead to a “second wind,” in which activity is then better tolerated. Isometric exercises that require strength, such as lifting heavy objects, squatting or standing on tiptoe, also may cause muscle damage.

Symptoms of this disease vary in severity among people and even within the same person from day to day. Symptoms usually don’t persist between attacks, although fixed weakness later in life is possible.

The symptoms are as followed: 

• Burgundy-colored urine (myoglobinuria)
• Fatigue
  
• Exercise intolerance, poor stamina 
  
• Muscle cramp, pain, stiffness, weakness 

Glycogen Storage Diseases

BARBECUE SAUCE

Here's an illustrated video on the different kinds of Glycogen Storage Disease that exist. 

For McArdle Disease (4:32 - 5:14)

We hope this broaden your understanding on the different kind of Glycogen Storage Disease!