TY - JOUR
T1 - Atypical Presentation for Friedreich Ataxia in a Child
AU - Caron, Elena
AU - Burns, Dennis
AU - Castro, Diana
AU - Iannaccone, Susan T.
N1 - Publisher Copyright:
© 2015 Wolters Kluwer Health, Inc.
PY - 2015/9/8
Y1 - 2015/9/8
N2 - The classic phenotype of Friedreich ataxia is characterized by dysarthria, progressive limb and trunk ataxia, loss of reflexes, and gait disturbance with the onset of disease before the second decade. Homozygous trinucleotide repeat expansion of GAA in the FXN gene is found in 98% of patients. Two-5% of all patients have a repeat expansion on one allele and a point mutation on the other allele. Atypical phenotype is found in 25% of patients. A 10-year-old boy presented with congenital biliary atresia and progressive gait abnormality. His examination was significant for spastic gait, hyperreflexia, and sensory neuropathy. Genetic testing revealed a compound heterozygous mutation in the FXN gene. The absence of dysarthria and ataxia, retention of reflexes, absence of diabetes, and variable development of cardiomyopathy support a slow progression of disease with compound heterozygous mutation at G130V. Missense mutations are rare causes of Friedreich ataxia that can only be detected by sequencing of the FXN gene. Sequencing of the FXN gene is essential to make an early diagnosis when there is an atypical phenotype.
AB - The classic phenotype of Friedreich ataxia is characterized by dysarthria, progressive limb and trunk ataxia, loss of reflexes, and gait disturbance with the onset of disease before the second decade. Homozygous trinucleotide repeat expansion of GAA in the FXN gene is found in 98% of patients. Two-5% of all patients have a repeat expansion on one allele and a point mutation on the other allele. Atypical phenotype is found in 25% of patients. A 10-year-old boy presented with congenital biliary atresia and progressive gait abnormality. His examination was significant for spastic gait, hyperreflexia, and sensory neuropathy. Genetic testing revealed a compound heterozygous mutation in the FXN gene. The absence of dysarthria and ataxia, retention of reflexes, absence of diabetes, and variable development of cardiomyopathy support a slow progression of disease with compound heterozygous mutation at G130V. Missense mutations are rare causes of Friedreich ataxia that can only be detected by sequencing of the FXN gene. Sequencing of the FXN gene is essential to make an early diagnosis when there is an atypical phenotype.
KW - Friedreich ataxia
KW - G130V
KW - atypical
KW - compound heterozygous
KW - missense mutation
UR - http://www.scopus.com/inward/record.url?scp=84941215577&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84941215577&partnerID=8YFLogxK
U2 - 10.1097/CND.0000000000000086
DO - 10.1097/CND.0000000000000086
M3 - Article
C2 - 26301374
AN - SCOPUS:84941215577
SN - 1522-0443
VL - 17
SP - 13
EP - 17
JO - Journal of Clinical Neuromuscular Disease
JF - Journal of Clinical Neuromuscular Disease
IS - 1
ER -