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 />
Conclusion: The (--/alpha alpha T ) genotype has more severe disease<br />
than those with the(--/-alpha) and the most molecular defect was (--/alpha<br />
3.7) .<br />
Key words: H disease, Hb H, genotype<br />
P12.072<br />
Deletion <strong>of</strong> the HFE gene is present at the population level in<br />
sardinia<br />
G. Le Gac 1 , A. Cao 2 , R. Congiu 3 , I. Gourlaouen 1 , C. Férec 1 , M. A. Melis 4 ;<br />
1 Inserm, U613; Etablissement Français du Sang; Centre Hospitalier Universitaire,<br />
Brest, France, 2 Istituto di Neurogenetica e Neur<strong>of</strong>armacologia CNR,<br />
Cagliari, Italy, 3 Ospedale microcitemico ASL8, Cagliari, Italy, 4 Dipartimento<br />
Scienze biomediche e biotecnologia, Università di Cagliari, Cagliari, Italy.<br />
Introduction: Very recently, we reported the case <strong>of</strong> a woman <strong>of</strong> Sardinian<br />
descent who had a major structural alteration in the HFE gene.<br />
Molecular characterization revealed an Alu-mediated recombination<br />
causing the loss <strong>of</strong> the complete HFE gene sequence. Although homozygous<br />
for the HFE deleted allele, the woman had a phenotype similar<br />
to that seen in most women homozygous for the common p.C282Y<br />
mutation. The deletion was not detected in a cohort <strong>of</strong> iron overload<br />
patients <strong>of</strong> Northern <strong>European</strong> descent. Here, we focused on DNA<br />
from Sardinia patients.<br />
Methods: We looked for the HFE deletion by using a rearrangement<br />
specific PCR. Positive results were confirmed by QFM-PCR and sequencing.<br />
Results: The HFE deleted allele was detected in two <strong>of</strong> 24 unrelated<br />
patients. Both patients were previously viewed as homozygous for the<br />
common p.H63D variation. At diagnosis, they presented with moderate<br />
iron overloads.<br />
Conclusion/Discussion: Deletion <strong>of</strong> the complete HFE gene sequence<br />
is not private, but present at the population level in Sardinia. Additional<br />
studies have been started to ascertain the assumption <strong>of</strong> a founder<br />
effect and precisely investigate frequency <strong>of</strong> the HFE deleted allele.<br />
In future, the recognition <strong>of</strong> several individuals with the HFE deletion<br />
will provides another opportunity to better understand penetrance <strong>of</strong><br />
the common p.C282Y/p.C282Y genotype, which remains a matter <strong>of</strong><br />
debates.<br />
P12.073<br />
The IVSI-5 (G◊C) β-thalassemia mutation in trans with the (delta )<br />
cD12 (AAt>AAA) Hb A 2 NYU in an iranian family<br />
A. Amirian, M. Karimipour, A. r. Kordafshari, M. Taghavi, M. Jafarinejad, M.<br />
Mossayebzadeh, S. Fathiazar, F. Bayat, N. Saeidi, S. Zeinali;<br />
Pasteur Institute, Tehran, Islamic Republic <strong>of</strong> Iran.<br />
Beta-thalassemia is the most common hereditary disorder in Iran. The<br />
abillity to premarital screening for thalassemia is in effect in Iran since<br />
1997.Typical heterozygous carriers <strong>of</strong> β-thalassemia have Hb A 2 >3.5,<br />
however, in some carriers <strong>of</strong> it is in normal range. Here we report the<br />
co-inheritance <strong>of</strong> β- and δ-globin gene mutations in an individual with<br />
microcytosis, hypochromia and normal Hb A 2 .Among couples refered<br />
to our lab from Primary Health Care centers (PHC) for molecular testing<br />
and prenatal diagnosis <strong>of</strong> β-thalassemia in Tehran, one individual<br />
was found to be atypical to be investigated for β-thalassemia. After obtaining<br />
informed consent,CBC and Hb electrophoresis was performed<br />
and genomic DNA was extracted from peripheral blood Leukocytes<br />
by salting out method. Amplification refractory mutation system PCR<br />
(ARMS-PCR) and direct DNA sequencing <strong>of</strong> δ-globin gene was exploited<br />
for detection <strong>of</strong> beta and delta globin gene mutations. The CBC<br />
and Hb electrophoresis pattern showed low indices and normal Hb A 2<br />
. ARMS-PCR technique for β-globin gene mutation revealed the beta 0<br />
IVS-I-5 (G to C) mutation. Direct DNA sequencing <strong>of</strong> δ-globin gene and<br />
hematological studies <strong>of</strong> the family members confirmed the presence<br />
<strong>of</strong> mutation in delta codon 12 (AAT > AAA) . We suggested this individual<br />
carries a delta globin gene mutation which is unable to increase<br />
the delta-globin chain output in response to beta-thalassemia. Direct<br />
DNA sequencing confirmed the co-inheritance <strong>of</strong> mutation in δ-globin<br />
gene as being codon 12 .<br />
P12.074<br />
Identification <strong>of</strong> a new β-globin variant (β133 GtG>AtG) in a<br />
family from messina (sicily-italy)<br />
G. Lo Giudice, M. Amorini, M. A. La Rosa, C. Di Bella, V. Procopio, G. E. Calabrò,<br />
P. Romeo, L. Grasso, F. Pugliatti, C. Salpietro, L. Rigoli;<br />
Unità Operativa di Genetica ed Immunologia Pediatrica, Messina, Italy.<br />
The hemoglobinopathies, or structural Hb variants, are attributable to<br />
aminoacid substitution in either the α or non-α chain. We studied five<br />
members <strong>of</strong> a family from Messina (Sicily-Italy). The proband, a 39<br />
years old male, was investigated because he showed a little decrease<br />
in MCV values (79 fl) and a slightly increased HbA 2 levels (3,5 %). Molecular<br />
analysis by directly sequencing <strong>of</strong> the amplified β globin gene<br />
revealed the presence <strong>of</strong> two single point mutations, a C>G transition<br />
at codon 70 (Gcc>GGc) and a G>A base substitution at codon 133<br />
(GtG>AtG). Therefore, we examined 5 members belonging to three<br />
generations <strong>of</strong> the family. The new variant, called Hb Messina, (β133<br />
Val>Met GtG>AtG) was identified in heterozygosis in four subjects.<br />
Moreover, Hb Hershey was identified in heterozygosis in one subject<br />
(III.2). Familiar analysis showed that G>A base substitution at codon<br />
133 was inherited from the father (I.1). Hb Messina shows asymptomatic<br />
clinical phenotype in heterozygotes subjects (I.1, II.3, II.4 and<br />
III.1); however, two family members had slightly increased HbA 2 levels<br />
(3,5-3,6 %) and showed a little decrease in MCV values (78-79 fl).<br />
The molecular analysis <strong>of</strong> the globin genes is important to perform<br />
an accurate diagnosis in the subjects with slightly alterations <strong>of</strong> the<br />
hematogical parameters.<br />
P12.075<br />
Genetic analysis <strong>of</strong> 31 iranian families segregating autosomal<br />
recessive hearing impairment<br />
M. A. Tabatabaiefar 1,2,3 , F. Alasti 3,4 , E. Farrokhi 2 , N. Peeters 5 , W. Wuyts 5 , M. R.<br />
Nooridaloii 1 , M. Hashemzadeh Chaleshtori 2 , G. Van Camp 3 ;<br />
1 Department <strong>of</strong> Medical <strong>Genetics</strong>, School <strong>of</strong> Medicine, Tehran University/Medical<br />
Sciences, Tehran, Islamic Republic <strong>of</strong> Iran, 2 Cellular and Molecular Research<br />
Center, School <strong>of</strong> Medicine, Shahrekord University <strong>of</strong> Medical Sciences,<br />
Shahrekord, Islamic Republic <strong>of</strong> Iran, 3 Department <strong>of</strong> Medical <strong>Genetics</strong>, University<br />
<strong>of</strong> Antwerp, 2610, Antwerp, Belgium, 4 Natinal Institute for Genetic Engineering<br />
and Biotechnology (NIGEB), Tehran, Islamic Republic <strong>of</strong> Iran, 5 Department<br />
<strong>of</strong> Medical <strong>Genetics</strong>, University hospital <strong>of</strong> Antwerp, 2610, Antwerp, Belgium.<br />
Autosomal recessive non-syndromic hearing impairment (ARNSHI) is<br />
the most common form <strong>of</strong> monogenic hearing impairment. It is a highly<br />
genetic heterogeneous disorder, as up to now 60 loci have been<br />
mapped for ARNSHI. Iran, with a high rate <strong>of</strong> consanguineous marriage<br />
is a good genetic resource for studying ARNSHI. The aim <strong>of</strong> our project<br />
is to identify novel genes or mutations for ARNSHI. A set <strong>of</strong> Iranian<br />
families suffering from ARNSHI were studied. DNA sequencing <strong>of</strong> the<br />
coding exon <strong>of</strong> GJB2, as well as linkage analysis <strong>of</strong> the DFNB1 locus<br />
was performed and linked families were excluded from further analysis.<br />
Seventeen out <strong>of</strong> 31 remaining families had S-link LOD scores higher<br />
than the threshold value for genome-wide significance <strong>of</strong> 3.3. Linkage<br />
analysis <strong>of</strong> the 14 most common ARNSHI loci was performed for all<br />
the families. To confirm linkage, further markers were genotyped in<br />
the linked families. Eight families showed linkage to 4 different loci: 4<br />
families to DFNB4 (SLC26A4), 1 to DFNB7/11 (TMC1), 1 to DFNB9<br />
(OTOF), 1 to DFNB2 (MYO7A) and 1 to DFNB21 (TECTA). Mutation<br />
screening <strong>of</strong> these 4 known genes is being performed in the linked families.<br />
Four SLC26A4 mutations have already been found in the DFNB4<br />
families. The results <strong>of</strong> this study support the notion that DFNB4 ranks<br />
second after GJB2 as a cause for ARNSHI. Twelve families with S-link<br />
LOD scores higher than 3.3 not linked to any <strong>of</strong> the 14 known loci will<br />
be included into genome-wide linkage analysis studies.<br />
P12.076<br />
Phenotype and genotype in females with pou f mutations<br />
S. Marlin1 , M. Moizard2 , A. David3 , N. Chassaing4 , M. Raynaud2 , L. Jonard1 , D.<br />
Feldmann1 , N. Loundon1 , F. Denoyelle1 , A. Toutain2 ;<br />
1 2 Hôpital Armand Trousseau, Paris, France, Hôpital Bretonneau, Tours, France,<br />
3 4 CHU, Nantes, France, Hôpital Purpan, Toulouse, France.<br />
X-linked deafness is a rare cause <strong>of</strong> hereditary isolated hearing impairment<br />
estimated as at least 1 or 2% <strong>of</strong> the non-syndromic hearing<br />
loss. To date 4 loci for DFN have been identified and only one gene,<br />
POU3F4 responsible for DFN3, has been cloned. In males, DFN3 is<br />
characterized by either a progressive deafness associated with peri-