11/13- Cases in Neurogenetics Flashcards
Case 1)
You are asked to evaluate a newborn in the NICU because of:
- Poor respiratory effort
- Hypotonia
- Mild limb contractures
What is your DDx?
DDx:
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Case 1 cont’d)
How will you think thorugh the DDx to arrive at the final diagnosis?
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Case 1 cont’d)
What tests would you order?
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Case 1)
Test results
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Case 1 cont’d)
- How would you manage this infant?
- What are the options for care?
- What genetic factor influences the phenotype in THIS diagnosis?
- What has been done (on a research basis) to treat THIS diagnosis?
- Is there a support group for THIS diagnosis? How would you find it?
Management:
- Focus on palliative care
- Progressive muscle function loss (inform)
- No respiratory function recovery
Options for care:
- Mechanical ventilation (prolongs life)
- Planned extubation/palliative care
Genetic factor influencing phenotype:
Research basis: increase expression of pseudo-gene (SMN-2)
- Go to www.clinicaltrials.gov to look at clinical trials/talk to patients
Support group: go through Genetic Alliance
Case 2)
- Your patient is a 33yo woman who is referred to you because her son, who was born at home, died shortly after birth.
- Little is known about her son, however a photograph of his face shows a normal appearing infant.
- Your patient said that her son could not breathe and was “like a rag doll”
What is the DDx?
DDx:
- Infant botulism (wouldn’t present at birth?)
- SMA
- Congenital Muscular Dystrophy
- Myotonic Dystrophy Type I
- Nemaline Myopathy
- Congenital Myasthenic Syndrome
- Sepsis
Case 2 cont’d)
- Is family history important? Why?
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Case 2 cont’d)
- What are aspects of the mother’s medical history and ROS are important
- Discuss key PE findings in your pt
PE: examine mother:
- Squeeze test (see if can release grip)
- Tap the thenar eminence
- Reflexes
This is myotonic dystrophy
Case 3)
- You are seeing a 4 year old male in clinic who comes to you for evaluation of weakness.
- His mother reports that she noticed that he has always been “clumsy” and has a difficult time climbing stairs.
- She reports that she cannot understand why he is so weak when he appears to have such big muscles, especially in his calves.
What is your DDx?
- Duchenne’s Muscular Dystrophy
- Becker (less likely)
- Other muscular dystrophies
Case 3 cont’d)
What other history is important?
What physical exam finding is classic for this Dx?
Do you ned to confirm this Dx with genetic test?
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What is the risk that the fetus is affected?
- Does the gender matter?
- How does family history influence this risk
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How would you approach genetic testing in this family?
- Who to test first
- Can you test fetus
- Future pregnancy testing?
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If mother harbors a mutation, what is her risk of medical disease?
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