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Phenotypic expression of familial amyloid polyneuropathy in Brazil

P L Bittencourt1, C A Couto, C Clemente

  • 1Portuguese Hospital of Salvador, Bahia, Brazil. plbbr@uol.com.br

European Journal of Neurology
|April 5, 2005
PubMed

Insights

Familial amyloid polyneuropathy (FAP) in Brazil, linked to the transthyretin Val30Met variant, shows early onset, especially in males and those with affected parents. This inherited condition primarily affects peripheral nerves.

Area of Science:

  • Genetics
  • Neurology
  • Rare Diseases

Background:

  • Familial amyloid polyneuropathy (FAP) is an inherited amyloidosis.
  • The transthyretin Val30Met variant is a primary genetic cause of FAP.
  • Clinical presentation of FAP can vary significantly across different populations.

Purpose of the Study:

  • To characterize the phenotypic expression of FAP in Brazilian patients with the Val30Met variant.
  • To compare Brazilian FAP cases with those reported in other international cohorts.
  • To investigate factors influencing disease onset and progression in Brazilian FAP patients.

Main Methods:

  • Retrospective analysis of 44 Brazilian patients diagnosed with FAP and carrying the Val30Met variant.
  • Data collection included patient demographics, age of onset, clinical symptoms, and family history.
  • Statistical analysis was performed to identify correlations between clinical features and patient characteristics.

Main Results:

  • The median age of onset for FAP in Brazil was 32 years, with peripheral neuropathy being the predominant initial symptom.
  • Earlier onset was observed in males (median 27 years) and in patients with affected parents (median 31 years).
  • Approximately 40% of family members, excluding parents and siblings, were also diagnosed with FAP, indicating high penetrance.

Conclusions:

  • FAP in Brazil, associated with the Val30Met variant, exhibits a phenotype similar to that in Portugal.
  • Key characteristics include high disease penetrance, early onset (particularly in males and those with a parental history), and predominantly peripheral neuropathy.
  • The findings suggest a significant influence of shared genetic factors on the expression of FAP in these populations.

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