METHODS

1
Allelic Associations of ANG with Sporadic ALS in
Irish and Swedish Patients J Phukan, R
McLaughlin, D S Lynch, W McCormack , M Greenway,
S Cronin, J Saunders, P Andersen , P Jakeman , O
Hardiman Beaumont Hospital (Dublin, IE)
University of Limerick (Limerick, IE) Umeå
University Hospital (Umea, SE), Trinity College
Institute of Neuroscience
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RESULTS cont/d ANG tagging
SNPs All five htSNPs showed significant
association with risk for SALS in the Irish
case-control group (Figure 2). Among these,
one marker (SNP4, rs17114699) was also replicated
in the Swedish cohort (T allele at SNP4 Ireland,
p 0.03 Sweden, p 0.0006). Several
independent SNPs at ANG were observed to affect
angiogenin expression in a graded, allele-dose
dependent manner in neurologically normal
individuals (CSF and plasma). This pattern
appeared attenuated in ALS patients.

INTRODUCTION Hypoxia responsive proteins may be
important in motorneuron survival, pathogenesis
of ALS and as possible therapeutic options.
Mutations in ANG (which codes for angiogenin)
have been identified in familial and sporadic
ALS. Multiple ANG haplotypes are associated with
sporadic ALS in the Irish population. We have
recently reported that serum angiogenin levels in
Irish ALS patients differ from controls.
METHODS cont/d For the SNP
genotyping study, 661 Irish and Swedish SALS
patients and 580 controls were genotyped. Commerc
ially available kits were used to perform ELISA
for the quantitative measurement of
angiogenin. Data from the CEPH panel of the
International HapMap Project was used to select 5
informative htSNPs covering the ANG gene.

Figure 2. ANG Genotypes and regulation of plasma
and CSF levels.
RESULTS CSF Angiogenin levels in CSF range
from 72.98ng/ml to 2284ng/ml.  Median levels
were not significantly different between control
and patient groups (p0.677) (Figure 1).
Angiogenin levels were 13 higher in males than
females (plt0.003) and increased with age
(plt0.01). Plasma Plasma angiogenin levels were
significantly different between the control and
patient groups (plt0.0005) (Figure 1). Median
angiogenin levels were higher in controls
compared to patients (see Figure 1). Levels
increased with age (plt0.018). A moderate
correlation was found between CSF angiogenin and
plasma angiogenin concentrations in all
participants (r0.277, plt0.0005).
Figure 1 Box-plots illustrating plasma and CSF
ANG levels of patient sub-groups and control
group.
CONCLUSION Multiple independent htSNP
associations exist with sporadic ALS (SALS) in
the Irish population. This study thus confirms
the previously observed association between ANG
variants and ALS in the Irish population.
Replication in the Swedish suggests that SNP4
confers increased susceptibility to SALS in a
wider population. Angiogenin expression in
controls is modulated by at least 3 htSNPs. This
graded, allele-dose dependent relationship is
significantly attenuated in patients, suggesting
a dysregulation of angiogenin expression in
sporadic ALS. These findings support the
hypothesis that angiogenin is a biologically
important protein in ALS.

• AIMS
• To determine whether angiogenin is present in
  cerebrospinal fluid (CSF).
• To quantify the range of angiogenin levels in CSF
  in ALS patients and controls and to investigate
  the relationship between CSF and plasma
  angiogenin levels.
• To determine whether genetic variations in the
  ANG locus control angiogenin expression.

METHODS CSF from 130 Swedish patients and plasma
from 128 Swedish patients with SALS was analysed.
Samples were compared with control CSF from a
similar number of unrelated, ethnically matched
controls. .