Neurology: Case of the Month

Test Yourself — Patient 67

Familial amyloid polyneuropathy (type I), with transthyretin gene mutation

1. Which of the following sets of patients with familial amyloid polyneuropathy (FAP) would be expected to benefit the most from orthotopic liver transplantation?
   • [ A ] Patients with dysautonomia and abnormal cardiocirculatory autonomic tests.
   • [ B ] Patients with severe sensorimotor deficits.
   • [ C ] Patients with isolated mild sensorimotor or sensory neuropathy.
   • [ D ] Patients with clinically significant nephropathy.
2. Which of the following statements is TRUE:
   • [ A ] Amyloid deposits contain only forms of the mutant or abnormal protein.
   • [ B ] Orthotopic liver transplantation for FAP type I causes a marked reduction in circulating forms of mutant transthyretin.
   • [ C ] Amyloid deposition nearly always occurs as a consequence of loss of the normal function of scavenging proteins such as apolipoprotein A1 and gelsolin.
   • [ D ] A and C are both true.
3. Sporadic amyloid polyneuropathy should be evaluated for serum and urine paraproteins by high resolution electrophoresis with immunofixation.
   • [ A ] True
   • [ B ] False
4. Which of the following statements is TRUE:
   • [ A ] Amyloid protein is deposited intracellularly in the heart, kidneys, eyes, and nerves.
   • [ B ] The most common mutation in familial amyloid polyneuropathy leads to a Val28Met substitution in the amino acid sequence of transthyretin.
   • [ C ] Familial amyloid polyneuropathy rarely causes the degree of cirrhosis or liver failure seen in liver diseases warranting transplantation.
   • [ D ] Absence of detectable cardiac or renal involvement virtually excludes a diagnosis of familial amyloid polyneuropathy, type I.
5. Which of the following clinical associations is LEAST likely to occur:
   • [ A ] Lax skin over face and corneal dystrophy - FAP type IV (gelsolin mutations).
   • [ B ] Ulcers - FAP type III (apolipoprotein A1 mutations).
   • [ C ] Prominent, late-onset carpal tunnel syndrome - FAP type II (transthyretin mutations).
   • [ D ] Leptomeningeal amyloid deposits - FAP type III (apolipoprotein A1 mutations).

 

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