Friedreich's ataxia: cardiac evaluation of 25 patients with clinical diagnosis and literature review.
OBJECTIVE
Cardiac evaluation (clinical, electrocardiographic and echocardiographic) of 25 Brazilian patients with clinical diagnosis of Friedreich's ataxia (FA) related to the frequency and the size of GAA repeats (unstable expansion of trinucleotide repeats that results in the disease).


METHODS
Clinical and cardiac study including electrocardiogram and echocardiogram of all patients and molecular analysis to detect the frequency and the size of GAA expansion, by polymerase chain reaction analysis.


RESULTS
Homozygous GAA expansion was detected in 17 patients (68%) - all typical cases. In 8 (32%) cases (6 atypical and 2 typical), no GAA expansion was observed, therefore it was not considered Friedreich's ataxia. All patients with GAA expansion (100%) had electrocardiographic abnormalities, and only 25% of the cases without GAA expansion had some abnormality on this exam. However, only 6% of all patients revealed some signals/symptoms suggestive of cardiac involvement.


CONCLUSIONS
A molecular analysis is essential to confirm the diagnosis of Friedreich's ataxia; however, an adequate cardiac evaluation, including an electrocardiogram, was extremely useful to better screening the patients which should perform these molecular analysis.
Albano
Lilian Maria José
LM
Child's Institute, Hospital das Clínicas, FMUSP.
Nishioka
Silvana Angelina Dório
SA
Moysés
Regina Lucia
RL
Wagenführ
Jaqueline
J
Bertola
Débora
D
Sugayama
Sofia Mizuho Miura
SM
Chong
A Kim
AK
D048868:Adaptor Proteins, Signal Transducing; D000293:Adolescent; D002312:Cardiomyopathy, Hypertrophic / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D005621:Friedreich Ataxia / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics; D011446:Prospective Studies; D019680:Trinucleotide Repeat Expansion
C079091:APBA1 protein, human; D048868:Adaptor Proteins, Signal Transducing; D009419:Nerve Tissue Proteins