AANP-OREN American Association of Neuropathologists Online Resource for Education in Neuropathology
Quiz 1
Congenital Myopathy
Kar-Ming Fung, M.D.1, Ph.D.1 and Steven A. Moore M.D., Ph.D. 2
1 Department of Pathology, the University of Oklahoma Health Sciences Center, Oklahoma City, OK, e-mail: karming-fung@ouhsc.edu (Corresponding Author)
2 Department of Pathology and the Iowa Center for Muscular Dystrophy Research, The University of Iowa, Iowa City, IA, e-mail: steven-moore@uiowa.edu
Last update: September 1st, 2006.
1. In general, which type of muscle fibers is more affected in congenital myopathies (examples of congenital myopathies include central core disease, nemaline body myopathies, congenital fiber size disproportion, centonuclear myopathy and others)?
A. Type I.
B. Type II.
C. There is not a general trend of preference.
2. Congenital myopathies are typically associated with what level of serum creatine kinase (CK)? (Normal range is 20-140 U/L)
A. In “extremely high” range (over 6,000 U/L)
B. In “high-thousand” range (3,000 to 6,000 U/L).
C. In “low-thousand”range (1,000 to 2,000 U/L).
D. In “high-hundred”range (500 to 1,000 U/L).
E. In “normal / high-normal” range (normal to under 500 U/L).
3. Ragged fibers suggestive of mitochondrial myoapthies are usually obvious in muscle biopsy material obtained in patients under 3 years of age?
A. True.
B. False.
4. For physical examination, muscular hypotonia carries the same meaning as muscular weakness?
A. True.
B. False.
5. Muscle biopsy is not a diagnostic procedure of choice for the diagnosis of spinal muscular atrophy (SMA) in infants?
A. True.
B. False.
6. The following panel demonstrates the histochemical observations on the muscle biopsy of a patient with an adenylate deaminase preparation.
Click on thumbnail to see image.
Which of the followings is true regarding patient with this type of result?
A. Most of these patients are symptomatic.
B. This condition is rare.
C. Asymptomatic patient may become symptomatic if a superimposed pathologic condition of muscle occurs.
D. Muscle with this condition usually shows also abnormal staining pattern with preparations for oxidative enzymes.
E. This condition is usually caused by the deletion of the AMPD1 gene.
Case A (Question 7-9): The following image was taken from the paraffin sections of the muscle biopsy obtained from a one month old male infant with the chief clinical manifestations of decreased fetal movement and polyhydraminos during gestation, severe hypotonia at birth, and post-natal respiratory insufficiency. The serum creattine kinase in serum was only mildly elevated. There is no facial dysmorphism and the infant was born to a normal mother with term gestation and uncomplicated delivery.
Click on thumbnail to see image.
7. What is the most likely diagnosis?
A. X-linked myotubular myopathy.
B. Pompe’s disease.
C. Congenital fiber size disproportion.
D. McArdle’s disease.
E. Congenital myotonic dystrophy.
8. Which of the followings is featured by infantile hypotonia, hypersomnia, and a small mouth with a thin and down turned upper lip that gives the mouth a triangular shape (“fish-mouth shaped mouth”)?
A. Werdnig-Hoffmann disease (SMA I).
B. X-linked myotubular myopathy.
C. Congenital fiber size disproportion.
D. Prader-Willi syndrome.
E. Fetal alcohol syndrome.
9. Which of the followings present typically as a fully alert infant, severe muscle weakness and hypotonia, a distended abdomen and a small chest, and preserved facial expression?
A. Werdnig-Hoffmann disease (SMA I).
B. X-linked myotubular myopathy.
C. Congenital fiber size disproportion.
D. Prader-Willi syndrome.
E. Fetal alcohol syndrome.
Case B (Question 10-13): The following image was taken from an NADH-TR preparation obtained from a 5 year-old girl with a chief complain of chronic muscle pain since, as per the description of her mother, 18 months of age. She has minor delay and minor difficulties in climbing stairs and running. Her serum creatine kinase was within normal limits.
Click on thumbnail to see image.
10. Which of the followings is true?
A. NADH is present only in mitochondria
B. Type I fibers appear dark on NADH-TR preparation.
C. The gene coding NADH is present in the mitochondrial DNA.
D. NADH-TR preparation is the preparation of choice for typing as it can distinguish type I and II fibers efficiently.
E. NADH-TR preparation can be performed on both frozen sections or formalin fixed, paraffin embedded sections.
11. The most likely diagnosis for this child is?
A. Central core disease.
B. Neurogenic atrophy.
C. Tubular aggregate myopathy.
D. Nemaline body myopathy.
E. Becker’s muscular dystrophy.
12. The entity being illustrated here is usually sex-linked recessive?
A. True.
B. False.
13. The entity being illustrated here is typically associated with which of the following life threatening conditions?
A. Status epilepticus.
B. Cardiac arrhythmia.
C. Congestive cardiomyopathy.
D. Malignant hypertension.
E. Malignant hyperthermia.
Case C (Question 14-15): The following electron micrograph was obtained from a 45 year old man who complained of ongoing fatigue and weakness with decreased endurance of exercise for several months.
Click on thumbnail to see image.
14. The structures being shown on the left half of the image are?
A. Mitochondria.
B. Glycogen.
C. Lipid storage.
D. Central core.
E. Tubular aggregates.
15. Which of the following is the usual enzyme histochemical profile for this type of structure?
A. Eosinophilic on hematoxylin-eosin, red on modified Gomori’s trichrome, dark on NADH-TR, dark on succinate dehydrogenase.
B. Basophilic on hematoxylin-eosin, red on modified Gomori’s trichrome, dark on NADH-TR, dark on succinate dehydrogenase.
C. Basophilic on hematoxylin-eosin, red on modified Gomori’s trichrome, dark on NADH-TR, pale on succinate dehydrogenase.
D. Basophilic on hematoxylin-eosin, red on modified Gomori’s trichrome, pale on NADH-TR, pale on succinate dehydrogenase.
E. These structures do not give a consistent pattern of histochemical reaction.
Case D (Question 16-19): The following image was obtained from a 52 year-old man who presented with a clinical history of muscle weakness for about 10 months in his arms and legs, occasional diploplia and difficulties in getting up from a squatting position. There was no skin rash or fever.
Click on thumbnail to see image.
16. The halo around the nuclei typically contains glycogen and mitochondria.
A. True.
B. False.
17. The central nuclei illustrated in the condition under discussion are morphologically normal under electron microscope in this case.
A. True.
B. False.
18. What is the most likely diagnosis of this patient?
A. X-linked myotubular myopathy.
B. Kugelberg-Welander disease.
C. Chronic non-specific myopathy with increase in central nuclei.
D. Mitochondrial myopathy.
E. Centronuclear myopathy.
19. Which of the followings is correct regarding the condition under discussion?
A. The pathology is related to the mutation of a gene located on chromosome 12p and is autosomal dominant.
B. This condition is usually autosomal dominant but autosomal recessive transmission has also been documented.
C. Most of the cases are X-linked recessive.
D. Most of the cases are X-linked dominant.
E. None of the above.
Case E (Question 20-23): The following image, with modified Gomori’s trichrome on frozen sections, was obtained from the muscle biopsy of a 7 year-old girl who had mild, non-progressive muscle weakness of proximal and distal limbs. The extraocular muscles were not affected but there was mild facial weakness.
Click on thumbnail to see image.
20. What is the most likely diagnosis of this patient?
A. Nemaline myopathy.
B. Mitochondrial myopathy.
C. McArdle’s disease.
D. Inclusion body myositis.
E. Desmin related myopathy (desminopathy).
21. The infantile form of this condition is often fatal?
A. True.
B. False.
22. Childhood onset is the least common form of this condition?
A. True.
B. False.
23. Which of the following genes have been related to this condition?
A. a-tropomyosin (TPM3) gene.
B. Nebulin (NEB) gene.
C. Sarcomeric actin (ACTA1) gene
D. b-tropomyosin (TPM2) gene gene.
E. All of the above.
