Clinical use of frataxin measurement in a patient with a novel deletion in the FXN gene.
J Neurol
; 260(4): 1116-21, 2013 Apr.
Article
in En
| MEDLINE
| ID: mdl-23196337
ABSTRACT
Friedreich ataxia (FRDA) is caused by a GAA expansion in the first intron of the FXN gene, which encodes frataxin. Four percent of patients harbor a point mutation on one allele and a GAA expansion on the other. We studied an Italian patient presenting with symptoms suggestive of FRDA, and carrying a single expanded 850 GAA allele. As a second diagnostic step, frataxin was measured in peripheral blood mononuclear cells, and proved to be in the pathological range (2.95 pg/µg total protein, 12.7 % of control levels). Subsequent sequencing revealed a novel deletion in exon 5a (c.572delC) which predicted a frameshift at codon 191 and a premature truncation of the protein at codon 194 (p.T191IfsX194). FXN/mRNA expression was reduced to 69.2 % of control levels. Clinical phenotype was atypical with absent dysarthria, and rapid disease progression. L-Buthionine-sulphoximine treatment of the proband's lymphoblasts showed a severe phenotype as compared to classic FRDA.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Friedreich Ataxia
/
Sequence Deletion
/
Iron-Binding Proteins
Limits:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
J Neurol
Year:
2013
Document type:
Article
Affiliation country:
Italy