Aldo Quattrone

Antonio Gambardella

Carmine Ungaro

Francesca Condino

Francesca L Conforti

Ida Manna

Maria Trojano

Paola Valentino

Rosalucia Mazzei

Virginia Andreoli

CiteSeerX

Neuroscience & Medicine, 2011, 2, 117-119 
doi:10.4236/nm.2011.22017 Published Online June 2011 (http://www.SciRP.org/journal/nm) 
Copyright © 2011 SciRes.                                                                                  NM 
117
Ile587Val Polymorphism of the eIF2B5 Gene as 
Susceptibility Factor for Multiple Sclerosis 
Carmine Ungaro1, Francesca L. Conforti1, Maria Trojano2, Ida Manna1, Virginia Andreoli1, 
Francesca Condino1, Paola Valentino3, Antonio Gambardella1,2,3, Aldo Quattrone1,2,3, Rosalucia Mazzei1 
 
1Institute of Neurological Sciences, National Research Council, Cosenza, Italy; 2Department of Neurological and Psychiatric Sci-
ences, “Aldo Moro” University, Bari, Italy; 3Institute of Neurology, University “Magna Graecia”, Catanzaro, Italy. 
Email: r.mazzei@isn.cnr.it 
 
Received October 8th, 2010; revised February 19th, 2010; accepted March 1st, 2010. 
 
ABSTRACT 
Mutations in the eIF2B gene cause the VWM disease. Genetic and biochemical data of MS patient and MRI data show-
ing VWM images similar to MS lesions, encouraged the present study in which we analyzed the eIF2B5 gene in 225 
unrelated MS patients to evaluate an overlapping between MS and VWM. A common variation Ile587Val was found 
very frequent in the MS patients respect normal controls, thus suggesting that Ile587Val should be considered as sus-
ceptibility factor in the development of MS. In conclusion, our data strongly highlight a possible involvement of the 
eIF2B5 in the development of MS. 
 
Keywords: Multiple Sclerosis, Vanishing White Matter Disease, eIF2B Gene, Stress-Sensitive Neurological Disorders 
1. Introduction 
Multiple sclerosis (MS) is an inflammatory chronic dis-
ease characterized by a demyelinating process, which is 
followed by neurodegeneration. Although the true etiol-
ogy remains elusive, MS seems to be a multifactor pa-
thology in which a predisposing genetic background 
added to an infection plays an important role [1]. A lot of 
evidence have provided that genetic factors contribute to 
disease susceptibility; in fact epidemiological studies 
estimated that the absolute risk of MS in a first-degree 
relative of a patient is 20 - 40 times the risk in the general 
population, with the most common case being an affected 
sibling [2], thus suggesting an autosomal recessive model 
of inheritance of MS candidate genes. 
Despite several linkage and association studies, the 
strongest and most consistently replicated evidence for a 
MS susceptibility gene has been localized to the Major 
Histocompatibility Complex (MHC) superlocus on 
chromosome 6p21.3 [3]. This data, together with the ob-
served clinical and histopathological heterogeneity of the 
disease, further supported the hypothesis that the MS- 
prone genotype results from multiple independent or in-
teracting polymorphic genes, each exerting a small or, at 
most, moderate effect to the overall risk [4]. Then it is 
likely that genetic heterogeneity exists, meaning that 
specific genes influence susceptibility and pathogenesis  
in some individual but not in others. Basing on these 
grounds, even other genetic elements located within the 
Human Leukocyte Antigen (HLA) Complex, i.e., Heat 
Shock Proteins (HSP) that have been shown to be strik-
ingly elevated in MS lesions, could have a role in the 
pathophysiology of MS [5]. 
HSPs are similar in function to the eukaryotic transla-
tion initiation factor eIF2B. It is an important regulatory 
pathway for the prevention of synthesis of denaturated 
proteins during cellular stress, and it functions in parallel 
with the production of heat shock proteins [6]. 
The eukaryotic translation initiation factor (eIF2B) con- 
sists of five subunits, each encoded by different genes 
(eIF2B1-5). The eIF2B gene is an important factor in the 
regulatory pathway that prevents the synthesis of dena-
turated proteins during cellular stress and whose func-
tions seem to work in parallel with the production of 
HSPs [6]. Mutations in this gene inherited as autosomal 
recessive trait are able to cause a stress-sensitive leu-
koencephalopathy known as Vanishing White Matter 
disease (VWM), also called Childhood Ataxia with Cen-
tral Hypomyelination (CACH) (OMIM 603896) [7]. This 
is a leukoencephalopathy with autosomal recessive in-
heritance. Magnetic Resonance Images of patients with 
VWM show a diffuse leukoencephalopathy with evi-
dence of progressive disappearance of the cerebral white  
Ile587Val Polymorphism of the eIF2B5 Gene as Susceptibility Factor for Multiple Sclerosis 118 
matter, which is seen on MRI by signals approaching 
those of cerebrospinal fluid on all pulse sequences in-
cluding protondensity and FLAIR sequences. Cavitating 
leukodistrophy has also been described, especially at the 
later stages of the disease, but this finding must not be 
considered a crucial exclusion diagnostic criteria [8]. 
Previous studies have reported cases of VWM in which 
MRI was strikingly similar to that observed in MS [9]. 
In view of the fact that eIF2B is essential for regula-
tion of protein synthesis in all cells of the body, espe-
cially under different stress conditions, it is not surprising 
that mutations in the gene subsequently have been re-
ported in other variants including acute fatal infantile 
forms with multiorgan involvement and Cree leukoen-
cephalopathy; slowly progressive juvenile conditions; 
and adult-onset disorders associated with ovarian dys-
genesis [10]. 
Genetic and biochemical data of MS patient and MRI 
data showing VWM images similar to MS lesions, en-
couraged the present study in which we analyzed the 
coding region of eukaryotic translation initiation factor 5 
(eIF2B5) to evaluate an overlapping between MS and 
Vanishing White Matter disease (VWM). 
2. Patients and Methods 
2.1. Patients 
We previously analyzed 11 pairs of siblings (22 patients) 
followed at the Institute of Neurology—University 
“Magna Graecia” of Catanzaro—Italy, all with definite 
MS [11]. The group of siblings consisted of 14 females 
and 8 males, ages ranging 27 - 46 years, with a mean 
disease onset of 23.7 + 8.3 years, all derived from the 
Southern Italy. As a control group we selected 10 age- 
and sex-matched healthy subjects from the same geo-
graphic area. In these patients we performed a mutational 
screening of the eIF2B5 gene in order to verify a possible 
link between MS and VWM and we initially performed 
this study because our affected patients were sib pairs, 
making hypothetical an autosomal recessive model of 
inheritance. Subsequently, the analysis has been ex-
tended, analyzing other 214 unrelated MS patients, all of 
them diagnosed as clinically established, definite MS, 
according to Poser criteria and derived from the Southern 
Italy too. More, 197 age- and sex-matched healthy sub-
jects from the same geographic area were included. 
2.2. Molecular Investigation 
After informed consent was obtained, DNA was extra- 
cted from whole blood samples using standard protocols. 
A mutational screening of the 16 exons of the eIF2B5 
gene and their exon-intron boundaries was performed by 
PCR using newly designed primer pairs. PCR reactions 
were carried out in 50 μl reaction volumes containing 
130 ng genomic DNA, 2.5U Transgenomic Optimase 
Polymerase in its 1X Buffer, MgSO4 1.5 mM, dNTPs 
200 μM each, primers 20 pmoles each. The amplicons 
were analyzed by Denaturing Performance Liquid Chro- 
matography (DHPLC) on a WAVE Nucleic Acid Frag-
ment Systems (Transgenomic Inc., Mountain Crewe, 
CA). Representative samples with an abnormal DHPLC 
profile were sequenced on an ABI Prism 3130 × l genetic 
analyzer, using the ABI Prism BigDye Terminator Cycle 
Sequencing Ready Reaction Kit (Applied Biosystems). 
2.3.Statistical Analysis 
The Hardy-Weinberg equilibrium was tested using Pear-
son’s chi-square goodness of fit test. The differences in 
allelic and genotypic distributions between cases and 
controls were assessed using chi-square test. Odd ratios 
with 95 percent confidence intervals (95% CI) was esti-
mated by contingency table. 
3. Results 
In the first group of analyzed subjects, no mutation was 
found in any of the coding regions in either the patients 
or the controls, except for a common variation in exon 13 
(Ile587Val; rs843358) in the heterozygous state in 6 MS 
patients and in the homozygous state in only 1 MS pa-
tient. This variation was also found in the heterozygous 
state in 3 out of 10 healthy controls. 
Furthermore, mutations were not found in any of the 
coding regions in either the remaining patients or the 
controls, except the variation in exon 13 (Ile587Val), 
detected in the heterozygous state in 83 patients, and in 
homozygous state in 12 patients. The variation was also 
found in the heterozygous state in 48 out of 207 control 
subjects and in homozygous state only in 2 out of control 
subjects. 
4. Discussion 
Although MS etiology still remains unclear, the genetic 
influence on both susceptibility and clinical phenotypes 
is unequivocal. Studies on candidate genes have focused 
the interest on different pathways (i.e., the autoimmune 
cascade, the axonal or myelin targets) but, despite very 
few results have been reached, each one of them is cru-
cial for adding another wedge of the puzzle. 
In our study, we investigated the gene coding the ε 
subunit of eIF2B because it is the gene in which was 
found the most of mutations causing the VWM disease 
and the only one in which were reported mutations caus-
ing VWM with milder phenotype [12]. 
As eIF2B5 gene mutations were not found in the 
eleven MS sib pairs, it was believable that VWM and 
familial MS are distinct diseases. On the other hand, a  
Copyright © 2011 SciRes.                                                                                  NM 
Ile587Val Polymorphism of the eIF2B5 Gene as Susceptibility Factor for Multiple Sclerosis 
Copyright © 2011 SciRes.                                                                                  NM 
119
Table 1. Allele and genotype frequency of the eIF2B5 gene 
polymorphism (Ile587Val) in MS patients and in normal 
subjects. Hardy-Weinberg equilibrium: Pz: χ2 = 0.352; 
p-value = 0.553; Ctrl: χ2 = 0.642; p-value = 0.423. 
Genotype 
frequencies 
Pz Ctrl OR (95% CI) 
AA 123 157 Ref. 
Aa 89 48 2.267 (1.550 - 3.613) 
Aa 13 2 8.297 (1.838 - 37.456)
Tot 225 207  
χ2 = 23.76; p-value < 0.001. 
 
Allele 
frequencies 
Pz Ctrl OR (95% CI) 
A 335 362 Ref. 
a 115 52 2.390 (1.668 - 3.424) 
Tot 450 414  
χ2 = 23.35; p-value < 0.001. 
 
common variation Ile587Val was found in the exon 13 in 
7 out of them, and in 3 control subject only. This finding 
had a very little relevance because of the slenderness of 
sample group, but encouraged us to enlarge our cohort 
despite other authors did not find any association be-
tween this polymorphism and MS [13]. 
In fact, analyzing other 214 unrelated MS patients and 
197 controls, we found that the polymorphism Ile587Val 
was very frequent in the MS patients respect normal con-
trols. A statistical analysis (χ2-test) suggests that poly-
morphism Ile587Val in exon 13 of the EIF2B5 gene 
should be considered as susceptibility factor in the de-
velopment of MS (χ2 = 23.76; p < 0.001) (Table 1). 
In conclusion, our data strongly suggest a possible in-
volvement of the eIF2B5 in the development of MS and 
that variations in the MS patient strongly depend on geo-
graphic and ethnic factors, thus suggesting the impor-
tance of knowledge the epigenetic contribution in the 
pathogenesis of MS. 
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Ile587Val Polymorphism of the eIF2B5 Gene as Susceptibility Factor for Multiple Sclerosis

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Ile587Val Polymorphism of the eIF2B5 Gene as Susceptibility Factor for Multiple Sclerosis

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