2008 Barcelona - European Society of Human Genetics

Normal variation, population genetics, genetic epidemiology
growth and cognitive impairment, limb malformations and occasional
multiple organ defects . The NIPBL gene encompasses 47 exons and
produces a 9 .5 kb transcript, which appears in several tissues with
different level of expression. Besides, the identification of multiple transcripts
in this gene suggest the presence of alternative splicing, a feature
that has not been yet studied. Here, we report the first systematic
analysis of the NIPBL splicing variants in human normal tissues .
NIPBL cDNA from adult brain, fetal skeletal muscle and leukocytes
was amplified in various overlapping fragments, spanning exons 1 to
47 . PCR products were separated by electrophoresis on agarose gel .
Additional bands of different length than expected were sequenced .
Several novel splicing variants bearing one or more skipped exons
were found, but only the variant with skipped exon 12 was found in all
tissues analyzed. This finding was subsequently confirmed by cloning.
The variant with deletion of exon 43 was present only in adult brain .
Our results provide a basis for more detailed studies of functional
significance of these transcripts and might expand our knowledge of
CDLS1 .
This work is supported by a grant from the Ministry of Health of Spain
(Ref. PI061343) and from the Diputación General de Aragón (Ref.
B20) .
P07.094
NOTCH mutations in young adult patients with a first stroke:
The PORTYSTROKE study - screening genetic conditions in
PORTuguese Young STROKE patients
S. Ferreira 1 , M. Viana-Baptista 2 , I. Costa 3 , J. M. Ferro 4 , J. P. Oliveira 3 , &. POR-
TYSTROKE Study Group 5 ;
1 Faculdade de Medicina, Porto, Portugal, 2 Hospital Garcia de Orta, Almada,
Portugal, 3 Faculty of Medicine, Porto, Portugal, 4 Hospital Santa Maria, Lisboa,
Portugal, 5 (NA), (NA), Portugal.
Background
Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts
and Leukoencephalopathy (CADASIL), a genetic disorder due to mutations
in the NOTCH3 gene, is associated with early onset of smallvessel
ischaemic cerebrovascular disease . The clinical spectrum of
CADASIL varies widely and the disease is probably under-diagnosed
in stroke patients .
Methods
Between 1/November/06 and 31/October/07, all patients aged 18-55
years presenting with a first stroke event to any of 12 major neurology
hospital departments in Portugal were offered genetic screening for
CADASIL. Strokes were classified according to usual clinical and brain
imaging criteria. Mutational analysis was limited to PCR amplification
and sequencing of NOTCH3 exons 4, 11, 18/19, as these have been
previously shown to contain ~80% of the mutations identified in Portuguese
patients with CADASIL .
Results
Out of a total of 625 eligible patients, 493 (78 .9%) consented to the genetic
analysis . Of these, 74% had ischaemic strokes, of which 28 .5%
were cryptogenic . Seven different missense mutations in the NOTCH3
gene were found in 8 patients (prevalence=1 .6%; 95%CI: 0 .8-3 .1%):
p .R163W; p .P167S; p .T577A; p .G595S; p .S978R (n=2); p .H981Y;
p.R1036Q. There was no significant association with any particular
type of stroke . None of these patients had a previous diagnosis or
family history of CADASIL .
Conclusion
The minimal estimate for the prevalence of NOTCH3 mutations among
Portuguese young adults presenting with first stroke is at least 1000
times higher than the estimated population prevalence of CADASIL .
The spectrum of pathogenic NOTCH3 mutations may be more varied
than previously recognised .
P07.095
Neuropeptide Y gene variation and association with alcohol
consumption in a spanish mediterranean population
F. Frances, J. V. Sorli, O. Portolés, P. Guillem-Sáiz, J. I. González, D. Corella;
Preventive Medicine Dept. and CIBER obn, Valencia, Spain.
Background and objective: Neuropeptide Y (NPY) is a neurotransmitter
widely distributed in the central nervous system . Both intraamygdalar
injection and overexpression experiments in animals have
demonstrated that increases of NPY in the amygdala reduces alcohol
intake and anxiety manifestations in anxious rats . In humans, some
studies have associated the Leu7Pro polymorphism in the NPY with
alcohol consumption, but the evidence is scarce . In the Spanish Mediterranean
population, the Leu7Pro variant is not polymorphic . Thus,
our aim was to identify novel exonic variants in the NPY as well as the
study previously described intronic variants, and their association with
alcohol consumption in this population .
Methods: 911 subjects (321 men and 590 women) from the Spanish
Mediterranean population were recruited . Alcohol consumption and
demographic and lifestyle variables were measured . Nucleotide sequence
determination and SNP analyses were carried out .
Results: Only one exonic SNP was detected by direct sequencing
(1258G>A or rs9785023; allele frequency 0 .47) . From the intronic
markers chosen (483A>G or rs13235938, 2517A>G or rs4722342 and
7065A>G or rs 4722343), only the last ones were polymorphic (allele
frequencies 0 .46 and 0 .40 respectively), and none of them were associated
with alcohol consumption . However, the 1258G>A SNP was associated
(recessive pattern) with higher alcohol intake in drinkers . This
association was particularly relevant in men with a moderate intake
(40±9 g/d in GG, 41±8 g/d in GA and 59±5 g/day in AA; pA in the NPY is associated with alcohol consumption
in the Mediterranean population .
P07.096
splitting of large and complex pedigrees for linkage analysis of
quantitative traits
A. V. Kirichenko, T. I. Axenovich;
Institute of Cytology and Genetics, Russian Academy of Science, Novosibirsk,
Russian Federation.
Pedigree splitting is applied when large pedigrees are used for linkage
analysis . Several algorithms of pedigree splitting have been proposed .
They are adapted to MCMC, but not to Lander-Green based methods .
The latter methods are sensitive to the pedigree size . None of the existing
methods restrict the fragment size, and thus, they do not guarantee
that all of the resultant sub-pedigrees can be efficiently analyzed
by the Lander-Green algorithm . Earlier we proposed a fast automatic
algorithm for splitting large pedigrees for subsequent Lander-Green
based analysis (Liu et al, 2008). The algorithm is specifically aimed to
deal with pedigrees obtained in disease-oriented studies in genetically
isolated populations, where affected individuals are remotely related to
each other through multiple lines of descent .
In contrast to pedigrees with rare diseases, in the pedigrees collected
for quantitative trait analysis many close relatives having measured
phenotypes and genotypes are considered as individuals of interest .
We present a graph theory based algorithm for automatic splitting such
pedigrees on the fragments of restricted size . This algorithm iteratively
selects the clique with maximum weight of its edges from the cliques
of restricted size. Weight of edge is defined as kinship between two
individuals corresponding to clique nodes . The algorithm is implemented
in a software package PedStr (http://mga .bionet .nsc .ru/soft/index .
html) .
We compared our program PedStr and the Greffa (Falchi et al, 2004)
program and demonstrated that linkage power calculated on the base
of sub-pedigrees obtained by PedStr was higher than for sub-pedigrees
obtained by Greffa .
P07.097
Association of interleukin-1 polymorphisms with periodontal
disease in mentally retarded
F. S. Bayoumi, E. H. A. Abouel-Ezz, H. M. Goumaa;
National Research Center, Cairo, Egypt.
Association between Interleukin (IL-1) gene polymorphisms & increased
susceptibility to periodontitis were suggested . The intent of
this study was determining prevalence of IL- 1 α & β genotype polymorphisms
among normal & mentally retarded Egyptian individuals .
Thirty normal volunteers(NV) (15-30 y) & 25 mentally retarded individuals
(MR) (6-16 y) were subjected to dental examination with recording
Gingival index scores (GI). IL -1 α and IL-1β loci were genotyped
by standard PCR restriction fragment length polymorphism assay .
Ten of (NV) showed good GI scores (70% were healthy & 30% had
initial periodontitis); .The remaining (20) had fair GI score (15 % with
initial periodontitis, 35% had moderate periodontitis&50% with severe