2008 Barcelona - European Society of Human Genetics

Clinical genetics
leles- is in accordance with its occurrence in Central Europe .
Supported by Grants IGA MZ NR9406, NR9215, MSMT 1M0520 and
GAUK 109/06 .
P01.073
the molecular-genetic analysis of AtP7B gene at the Russian
patients with Wilson disease
T. Matveeva 1 , E. Zaklyazminskaya 2 , A. Polyakov 1 ;
1 Research Centre for Medical Genetics, Moscow, Russian Federation, 2 Centre
of Molecular Genetics, Odintsovo, Moscow Region, Russian Federation.
Wilson’s disease (hepatolenticular degeneration) is severe hereditary
autosomal recessive disorder, representing combined injury of internal,
first of all a liver, and a brain (the basal ganglia), that is caused
by accumulation in their cells of copper . Defect of copper-transporting
ATPase P-type, being a product of gene ATP7B responsible for development
of Wilson disease, leads to abnormalities of inclusion copper
into ceruloplasmin, responsible for its export .
The purpose of our investigation is search and determination of frequencies
of mutations in ATP7B gene on materials of the Russian patients
with the diagnosis «Wilson disease» . In research the method
of the SSCP-analysis with the following direct sequencing was used .
Search and identification of mutations was spent at 104 unrelated probands
(208 chromosomes) . The frequency of the most frequent for
the Russian population mutations in exon 14 (H1069Q) and exon 15
(c.3400delC) amounted at 40,4 % and 2,4 %, respectively .
Eight rare mutations were found in exon 5 c.1744_1745delAT at one
patient, and c.1770insT at three patients; in exon 7 - IVS7DS+3a>g
at one patient; in exon 8 - c.2304_2305insC at one patient; in exon
14 - E1064K at one patient and c.3083_3085delAGA>G also at
one patient; in exon 15 - Gly1111Asp at one patient; and in exon 18
- c.3888delC also at one patient . All the rare mutations listed above
have been detected in a heterozygous state . Mutations c.1770insT,
c.2304_2305insC and c.3888delC have been identified for the first
time. Also six polymorphisms were identified: c.1-75C>A, c.1-122ins-
GCCGC, c.1366G>C, K832R, Arg952Lis, A1140V.
P01.074
Preliminary results of Neonatal screening program for Wilson
disease in Greece and reporting of novel variants in ATP B gene
M. Tzetis 1 , M. Poulou 1 , N. Manolaki 2 , T. Karpathios 3 , K. Lama 4 , E. Kanavakis 1 ;
1 Department of Medical Genetics, Athens University, Athens, Greece, 2 1st Department
of Paediatrics, University of Athens, St Sophia’s Children’s Hospital,
Athens, Greece, 3 2nd Department of Paediatrics, University of Athens, P. and
A. Kyriakou Children’s Hospital, Athens, Greece, 4 Department of Paediatrics,
Kalymnos General Hospital, Kalymnos, Greece.
Wilson disease (WND) is an autosomal recessive genetic disorder and
heterozygous carriers do not show symptoms of the disease . WND is
caused by mutations in the ATP7B gene and exhibits substantial allelic
heterogeneity . WND is observed with a prevalence of approximately
1:30000, a carrier frequency of 1 in 90 and is similar among many
ethnic groups .
However the gene frequency is increased in the Sardinian population
and the Island of Grand Canaries. In these populations specific mutations
reach high frequencies due to inbreeding and founder effects .
Preliminary neonatal screening results have also shown increased
carrier frequencies in certain parts of Greece . In order to estimate the
exact carrier frequencies in areas with increased incidence of disease
a neonatal screening program was established . Out of a 100 newborns
tested, for the two commonest mutations (H1069Q and R969Q), from
the Island of Kalymnos we identified 89 normal, 11 carriers and 2 asymptomatic
patients . Taking into account the carrier frequency for the
general population there is a statistically significant increase in this
area with a p value of 0 .07 (Pearson’s Chi Square) . The method used
for the neonatal screening is a capture down protocol designed on
Nanochip® 400 System .
We also report the identification of 6 novel variants in the ATP7B gene
[p .I930M and p .V1036I (ex .12), p .Y1464S (ex .21), p .N1128Y (ex .15),
c.4125-23A>G (IVS21), and c.1544-12C>T (IVS3)], identified by
DGGE analysis and direct sequencing . The effects of these mutations
were assessed in combination with the clinical phenotype and using in
silico analysis (“PolyPhen” and “SIFT”) .
P01.075
ABcD2 peroxisomal transporter in the metabolism of long-chain
saturated and w9 monounsaturated fatty acids
M. Girós 1,2 , M. Ruiz 3,2 , S. Fourcade 3,2 , T. Pampols 1,2 , C. Camps 1 , A. Pujol 3,2 ;
1 IBC Servei de Bioquímica i Genética Molecular, Hospital Clinic, Barcelona,
Spain, 2 Centro de Investigación Biomédica en red de enfermedades raras (CI-
BERER) ISCIII, Barcelona, Spain, 3 Institut de Investigació Biomédica Bellvitge
(IDIBELL), Barcelona, Spain.
ABCD2 peroxisomal transporter in the metabolism of long-chain saturated
and w9 monounsaturated fatty acids
Peroxisomes are essential organelles exerting key functions in fatty
acid metabolism, such as the degradation of very long-chain fatty
acids (VLCFAs) . VLCFAs accumulate in X-adrenoleukodystrophy (X-
ALD), a disease caused by a deficiency of the ABCD1 peroxisomal
transporter . Its closest homologue, ABCD2, exhibits a high degree of
functional redundancy on the catabolism of VLCFAs, being able to
prevent X-ALD-related neurodegeneration (Pujol A . et al . 2004, Hum
Mol Genet 13:2997-3006). In search for specific roles of ABCD2, we
screened fatty acid profiles of mutant mice lacking Abcd2 in adrenal
glands, spinal cord and sciatic nerve, the target tissues of these mice
(Ferrer et al .(2005) Hum Mol Genet 14(23):3565-3577), and in liver after
different conditions such as fasting and feeding with a VLCFA-rich
diet, by gas-liquid chromatography . Our results indicate that ABCD2
plays a role in the degradation of long-chain saturated and ω9-monounsaturated
fatty acids, enlarging the spectrum of functions attributed
to date to peroxisomes .
P01.076
mitochondria depletion underlying neurodegeneration in X-ALD?
S. Fourcade 1,2 , J. Galino 1,2 , A. Schlüter 1,2 , J. Martínez-García 1,2 , F. Villarroya 3,4 ,
E. García-Arumi 5,2 , T. Andreu 5,2 , P. Aubourg 6 , A. Pujol 7,2 ;
1 Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L’Hospitalet de Llobregat-Barcelona,
Spain, 2 CIBERER, ISCIII, Barcelona, Spain, 3 Bioquimica i
Biologia Molecular, and Institut de Biomedicina IBUB, Universitat de Barcelona,
Barcelona, Spain, 4 CIBER Fisiopatologia de la Obesidad y Nutrición, ISCIII,
Barcelona, Spain, 5 Department Patologia Mitocondrial i Neuromuscular, Centre
d’Investigacions en Bioquímica i Biología Molecular (CIBBIM), Institut de Recerca
Hospital Universitari Vall d’Hebrón, Barcelona, Spain, 6 INSERM U745,
Department of Pediatric Neurology, Hôpital Saint-Vincent de Paul, University
René Descartes, Paris, France, 7 Catalan Institution of Research and Advanced
Studies (ICREA), Barcelona, Spain.
X-linked adrenoleukodystrophy (X-ALD) is the most frequent inherited
monogenic demyelinating disease (minimal incidence 1:17,000) .
X-ALD leads to death in boys or to motor disability in adults (adrenomyeloneuropathy
or AMN) . The disease is caused by loss of function
of the ABCD1 gene, a peroxisomal ATP-binding cassette transporter,
which function is related to defective β-oxidation of very long-chain
fatty acids (VLCFA) in peroxisomes . Therefore, a hallmark of the disease
is the accumulation of VLCFA in plasma and tissues . The mouse
model for X-ALD (Ald knock-out) exhibit a late-onset phenotype closely
related to adrenomyeloneuropathy, with neurodegenerative features
beginning at 15 months of age (1,2) . Using microarrays, Q-PCR and
Western Blots of mouse spinal cords, we have identified a mitochondria
depletion as very early event in the pathogenesis (3 .5 months
of age) . RIP140 (Receptor interacting protein 140), a nuclear co-repressor
of mitochondria biogenesis, is upregulated in spinal cord from
Aldko mice . VLCFA are able to induce RIP140 in ex vivo organotypic
spinal cord slice culture . We have also observed a mitochondria depletion
in the affected white matter of CCALD (Cerebral Childhood ALD)
and cerebral AMN compared to control individuals . This depletion is
correlated to a higher level of RIP140 in the non-affected white matter
of X-ALD patients . This could be disease causative, or at least,
contribute significantly to the neurodegenerative cascade in X-ALD
physiopathogenesis .
(1) Pujol et al, Hum Mol Genet. 2002 Mar 1;11(5):499-505; (2) Pujol et
al, Hum Mol Genet. 2004 Dec1;13(23):2997-3006
P01.077
molecular analysis of renal hypouricemia in Japan: evidence of
a single origin for a common mutation G774A in SLC A
K. Ichida 1,2 , N. Kamatani 3 , M. Hosoyamada 4 , S. Kamitsuji 5 , I. Hisatome 6 , T.
Hosoya 2 ;
1 Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan, 2 Jikei Univer-