Complete FXN deletion in a patient with Friedreich's ataxia.
Most patients (98%) with Friedreich's ataxia (FRDA) are homozygous for the GAA repeat expansion in FXN. Only a few compound heterozygous patients with an expanded repeat on one allele and a point mutation or an intragenic FXN deletion on the other allele are described. In a minority of the patients only a heterozygous pattern of the repeat expansion can be detected. Using array analysis after GAA repeat expansion testing, we identified a FRDA patient who is compound heterozygous for an expanded GAA repeat and a complete FXN deletion. Since not only repeat expansions and point mutations, but also large rearrangements can be the underlying cause of FRDA, a quantitative test should also be performed in case a patient shows only one allele with an expanded GAA repeat in FXN.
Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands. a.vandenouweland@erasmusmc.nl
Ans M W
AM
van den Ouweland
Rick
R
van Minkelen
Galhana M
GM
Bolman
Cokkie H
CH
Wouters
Cindy
C
Becht-Noordermeer
Wout H
WH
Deelen
J Marianne C
JM
Deelen-Manders
Elly P F
EP
Ippel
Jasper
J
Saris
Dicky J J
DJ
Halley
D000328:Adult; D005260:Female; D005621:Friedreich Ataxia / Q000235:genetics*; D017353:Gene Deletion; D006579:Heterozygote; D006801:Humans; D033862:Iron-Binding Proteins / Q000235:genetics*; D008297:Male; D010375:Pedigree; D019680:Trinucleotide Repeat Expansion / Q000235:genetics*; D000096923:Frataxin
D033862:Iron-Binding Proteins; D000096923:Frataxin