2009 Vienna - European Society of Human Genetics
2009 Vienna - European Society of Human Genetics
2009 Vienna - European Society of Human Genetics
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Molecular basis <strong>of</strong> Mendelian disorders<br />
lymphatic gusher at stapes surgery and with a characteristic inner ear<br />
malformation. We have defined the phenotype <strong>of</strong> 8 independent females<br />
carrying POU3F4 anomalies. A late-onset hearing loss is found<br />
in 3 patients. Only one has an inner ear malformation. No genotype/<br />
phenotype correlation is identified.<br />
P12.077<br />
An autosomal recessive nonsyndromic deafness locus is<br />
assigned to chromosome 18q12.3-21.1<br />
E. Pras 1 , H. Masri 1 , H. Reznik Wolf 1 , A. Abu 1 , Z. Brownstein 2 , K. B. Avraham 2 ,<br />
M. Frydman 1 ;<br />
1 Danek Gartner Institute <strong>of</strong> <strong>Human</strong> <strong>Genetics</strong>, Tel Hashomer, Israel, 2 Dept. <strong>of</strong><br />
<strong>Human</strong> Molecular <strong>Genetics</strong> & Biochemistry, Sackler School <strong>of</strong> Medicine, Tel<br />
Aviv, Israel.<br />
We studied a large non-consanguineous Ashkenazi family in which 5<br />
<strong>of</strong> 10 children suffer from pr<strong>of</strong>ound, prelingual hearing loss. A genome<br />
wide search mapped the disease gene to a n 8 Mb interval on chromosome<br />
18q12.3-21.1, and a maximum lod score <strong>of</strong> 3.03 was obtained<br />
with the marker AC021763 at θ =0.00. Saturation <strong>of</strong> the region with<br />
additional polymorphic markers and SNP’s revealed a 3.5 Mb homozygous<br />
interval in the affected sibs. The region contains 12 known genes,<br />
none <strong>of</strong> which have been previously associated with hearing loss. Sequencing<br />
<strong>of</strong> one gene from the interval, SLC14A1 did not reveal any<br />
pathogenic variants in the exons or in the flanking intronic sequences.<br />
Currently additional genes are being sequenced. These results define<br />
a novel locus for autosomal recessive hearing loss on chromosome<br />
18q12.3-21.1.<br />
P12.078<br />
High-resolution breakpoint mapping <strong>of</strong> novel rearrangements<br />
involved in alpha- and beta-thalassemia using arraycomparative<br />
Genomic Hybridization (acGH)<br />
M. Phylipsen, I. P. Vogelaar, Y. Ariyurek, J. T. den Dunnen, P. C. Giordano, C.<br />
L. Harteveld;<br />
Leiden University Medical Center, Leiden, The Netherlands.<br />
Thalassemias are hereditary microcytic hypochromic anemias characterized<br />
by abnormalities in hemoglobin production due to reduced expression<br />
<strong>of</strong> either the beta-globin gene, leading to beta-thalassemia, or<br />
the alpha-globin genes, giving rise to alpha-thalassemia. About 10% <strong>of</strong><br />
the beta-thalassemias and 90% <strong>of</strong> the alpha-thalassemias are caused<br />
by deletions in either globin gene cluster. In a previous study, we applied<br />
Multiplex Ligation-dependent Probe Amplification (MLPA) to<br />
characterize large rearrangements in the alpha- and beta-globin gene<br />
cluster. Several new deletions and duplications were found, however,<br />
the exact breakpoint sequences are still unknown. To facilitate confirmation<br />
by breakpoint PCR and to gain more insight in the mechanisms<br />
causing these rearrangements we decided to determine the precise<br />
location <strong>of</strong> breakpoints.<br />
Array Comparative Genomic Hybridization (aCGH) measures DNA<br />
copy number differences between a reference and a patient’s genome<br />
sample thereby detecting and mapping deletions and duplications.<br />
We used high resolution tiling arrays with 135,000 probes spaced at<br />
a density <strong>of</strong> ~15 bp to map the breakpoints to an interval that can be<br />
validated by PCR and sequencing. The array was hybridized to a set<br />
<strong>of</strong> 55 thalassemia patients who were found to carry a deletion in the<br />
alpha- or beta-globin gene cluster. The fine mapping results were used<br />
to design breakpoint PCRs and resulting fragments were sequenced<br />
to determine the precise breakpoint.<br />
P12.079<br />
Multiplex ligation-probe dependent amplification (MLPA) and<br />
Hemophilia A: detection <strong>of</strong> deletions in patients and tool for<br />
carrier status in female relatives.<br />
R. Santacroce1 , V. Longo1 , V. Bafunno1 , F. Sessa1 , M. Chetta1 , M. Sarno1 , N.<br />
Bukvic1 , G. D’Andrea1 , M. Margaglione1,2 ;<br />
1 2 Genetica Medica, Foggia, Italy, Unita’ di Emostasi e Trombosi I.R.C.C.S.<br />
“Casa Sollievo della S<strong>of</strong>ferenza”,, San Giovanni Rotondo, Italy.<br />
Haemophilia A is an X-linked bleeding disorder caused by mutations<br />
widespread in the human coagulation F8 gene. Most <strong>of</strong> the mutations<br />
in the F8 gene are detectable using genomic sequencing analysis.<br />
However, deletions <strong>of</strong> one or more exons or encompassing the entire<br />
gene can go undetected, especially in heterozygous females.<br />
Recently, MLPA has been broadly applied to gene mutation screening<br />
to detect exon deletions and duplications. Different deletions were detected<br />
using MLPA assay on 25 patients affected by severe haemophilia<br />
A, resulted mutation negative by sequencing analysis. Traditional<br />
PCR failed to amplify one or more exons in some <strong>of</strong> these patients and<br />
we decided to use the MLPA test in order to confirm the conjectured<br />
deletions: 7 deletions were revealed in haemophiliacs patients and we<br />
identified the carrier status in 2 female.<br />
F8 mutational screening could be improved by adding MLPA to sequence<br />
analysis and MLPA is a helpful tool in order to define the status<br />
<strong>of</strong> carriers in female relatives <strong>of</strong> haemophiliacs with deletions <strong>of</strong> one or<br />
more exons <strong>of</strong> F8 gene. It is to underline the importance <strong>of</strong> performing<br />
a molecular analysis in females suspected haemophiliacs carriers: the<br />
main obstacle to their counselling is the impossibility to demonstrate<br />
a heterozygous status because <strong>of</strong> the amplification <strong>of</strong> the exon/s that<br />
is/are present on the normal X chromosome. So, the only way to make<br />
a definitive diagnosis is to detect the mutation in F8 gene and MLPA<br />
provides an important tool for the detection <strong>of</strong> its complete mutational<br />
spectrum.<br />
P12.080<br />
Genotyping <strong>of</strong> coagulation Factor iX gene in Hemophilia B<br />
Patients <strong>of</strong> Esfahan Province<br />
L. Kokabee 1,2 , N. karimi 1 , S. Zeinali 1 , M. Karimipoor 1 ;<br />
1 Molecular Medicine dept., Biotechnology Center, Pasteur Inistitute <strong>of</strong> Iran,<br />
Tehran, Islamic Republic <strong>of</strong> Iran, 2 Khatam University, Tehran, Islamic Republic<br />
<strong>of</strong> Iran.<br />
Hemophilia B, Christmas disease, is an X-linked bleeding disorder<br />
caused by the functional deficiency <strong>of</strong> blood coagulation factor IX. The<br />
disease is due to heterogeneous mutations in the factor IX gene (F9),<br />
located at Xq27.1. It spans about 34 kilobases (kb) <strong>of</strong> genomic DNA.<br />
The aim <strong>of</strong> this study was molecular analysis and genotype- phenotype<br />
correlation <strong>of</strong> hemophilia B patients in Isfahan province, Iran. After<br />
obtaining informed consent, genomic DNA was extracted from the peripheral<br />
blood <strong>of</strong> 37 patients referred from Isfahan hemophilia center,<br />
by standard methods. PCR amplification, SSCP and CSGE techniques<br />
were performed for scanning <strong>of</strong> the all functional-important regions <strong>of</strong><br />
the F9 gene. DNA sequencing were performed for those with different<br />
migration patterns in SSCP or CSGE by chain termination method. In<br />
addition, haplotype were constructed using four the DdeI, TaqI, HhaI<br />
and MnlI restriction fragment length polymorphisms (RFLPs) markers.<br />
The sequencing results showed 70.3% missense mutation, 18.9%<br />
nonsense mutation, 8.1% deletion, 2.7% insertion. In this study, <strong>of</strong> the<br />
19 hemophilia B patients <strong>of</strong> the Kashan, all <strong>of</strong> them were represented<br />
substitution (G6472A) that could represent a founder effect. Five novel<br />
mutations which have not been reported in hemophilia B mutation<br />
database, were also found. The information obtained from this study<br />
could be used to diagnose potential female carriers in families with<br />
hemophilia B patients and prenatal diagnosis.<br />
P12.082<br />
molecular screening <strong>of</strong> 980 cases <strong>of</strong> suspected hereditary optic<br />
neuropathy with a report on 77 novel OPA1 mutations<br />
M. Ferré 1,2,3 , D. Milea 4,5 , A. Chevrollier 1,3 , H. Dollfus 6,7,8 , C. Ayuso 9 , S. Defoort<br />
10,11,12 , C. Vignal 13 , X. Zanlonghi 13,14 , J. Charlin 15,16 , J. Kaplan 17,18,19 , S.<br />
Odent 15,20 , C. P. Hamel 21,22 , V. Procaccio 2,3,23 , P. Reynier 1,2,3 , P. Amati-Bonneau 1,3 ,<br />
D. Bonneau 1,2,3 ;<br />
1 INSERM, U694, Angers, France, 2 Université d’Angers, Faculté de Médecine,<br />
Angers, France, 3 CHU d’Angers, Département de Biochimie et Génétique,<br />
Angers, France, 4 Glostrup Hospital, Department <strong>of</strong> Ophthalmology, Glostrup,<br />
Denmark, 5 University <strong>of</strong> Copenhagen, Copenhagen, Denmark, 6 INSERM,<br />
Equipe Avenir 3439, Strasbourg, France, 7 Université Louis Pasteur-Strasbourg,<br />
Faculté de Médecine, Laboratoire de Génétique Médicale, Strasbourg, France,<br />
8 CHRU de Strasbourg, Service de Génétique Médicale, Strasbourg, France,<br />
9 Fundación Jiménez Díaz, Servicio de Genética, CIBERER, Madrid, Spain,<br />
10 CNRS, UMR 8160, Lille, France, 11 Université de Lille 2, Lille, France, 12 CHRU<br />
de Lille, Hôpital Roger Salengro, Service d’Explorations Fonctionnelles de la<br />
Vision, Lille, France, 13 Fondation Rothschild, Département d’Ophtalmologie,<br />
Paris, France, 14 Clinique Sourdille, Laboratoire d’Explorations Fonctionnelles<br />
de la Vision, Nantes, France, 15 Université de Rennes 1, Faculté de Médecine,<br />
Rennes, France, 16 CHU de Rennes, Service d’Ophtalmologie, Rennes, France,<br />
17 INSERM, U781, Unité de Recherches Génétique et Epigénétique des Maladies<br />
Métaboliques, Neurosensorielles et du Développement, Paris, France,<br />
18 Université Paris Descartes, Faculté de Médecine, Paris, France, 19 AP-HP,