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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Clinical genetics and Dysmorphology<br />
tions, using gap-PCR for deletions and restriction analysis for point<br />
mutations. The male resulted heterozygous Alpha2IVS1-5nt, while the<br />
woman was negative.We checked the results using a RDB commercial<br />
kit, able to detect 22 alpha-globin mutations.<br />
The female showed a double gene deletion(--SEA), not tested in the<br />
first approach, while the point mutation was not present in the male.<br />
Following direct sequencing we can detect a novel deletion <strong>of</strong> 24 bp<br />
adjacent to the 5nt-pathogenic deletion: this variation affected the restriction<br />
site used for the first diagnosis by RFLP.However, a bioinformatic<br />
analysis excluded a possible functional meaning. Since the<br />
female had performed an amniocentesis for advanced maternal age,<br />
we explored the presence <strong>of</strong> these mutations in foetal cells too.We<br />
found the--SEA,but not the 24nt-deletion.We confirmed by MLPA the<br />
prenatal diagnosis, but unexpectedly MLPA failed to amplify one probe:<br />
8488-L8410, located between HBA1P andHBA2.Sequencing the corresponding<br />
region we identified a SNP in the father and in the foetus,<br />
responsible for the lack <strong>of</strong> amplification at MLPA.<br />
Failing the genotype characterisation, the couple would be wrongly<br />
considered at risk for HBH in their children.This experience allowed us<br />
to conclude that molecular characterisation <strong>of</strong> globin genes, although<br />
widely and routinely diagnosed, must be performed by laboratories<br />
with consistent cultural background and with availability <strong>of</strong> a panel <strong>of</strong><br />
articulated methods for assuring accurate testing.<br />
P02.171<br />
mLPA: A screening tool for molecular diagnosis <strong>of</strong> unknown<br />
alpha thalassemia deletions<br />
M. S. Fallah 1,2 , S. A. Aleyasin 1 , R. Mahdian 3 , M. Karimpour 3 , A. Ebrahimi 1 , M.<br />
Raeisi 2 , S. Kianfar 2 , M. Sadeghi 2 , S. Zeinali 3,2 ;<br />
1 National Institute for Genetic Engineering and Biotechnology (NIGEB), Tehran,<br />
Islamic Republic <strong>of</strong> Iran, 2 Kawsar <strong>Human</strong> <strong>Genetics</strong> Research Center, Kawsar<br />
Genomics & Biotech Center, Tehran, Islamic Republic <strong>of</strong> Iran, 3 Pasteure Institute,<br />
Tehran, Islamic Republic <strong>of</strong> Iran.<br />
Introduction: Alpha thalassemia is the most common hemoglobin<br />
disorder in Iran. Most <strong>of</strong> known alpha thalassemia mutations include<br />
deletion <strong>of</strong> one or both alpha globin genes. Its importance is mainly<br />
due to its role in making a correct decision for performing prenatal<br />
diagnosis (PND) and differentiating unknown alpha thalassemia from<br />
normal HbA2 beta thalassemia. MLPA, a recently developed simple<br />
technique suitable for rapid quantitative analysis <strong>of</strong> deletions and duplications,<br />
was used to determine new deletion in cases suspected <strong>of</strong><br />
alpha thalassemia.<br />
Material and Methods: Couples referred to Kawsar Genomics Center<br />
for PND investigated for common deletional alpha-globin mutations<br />
and point mutation using multiplex Gap-PCR and direct sequencing<br />
respectively. Those remained unknown, further investigated for other<br />
deletions by MLPA methods which performed. After denaturation,<br />
hybridization and ligation, PCR-amplification was performed with the<br />
specific SALSA primers. Electrophoresis <strong>of</strong> PCR products performed<br />
using ABI-3130 genetic-analyzer.<br />
Result: Thirty three suspected cases with low MCV, low MCH and normal<br />
HbA2 included in the study. No alpha globin gene mutation was<br />
detected in conventional investigation for common deletions and point<br />
mutations. In MLPA study <strong>of</strong> globin gene cluster a variety <strong>of</strong> diverse<br />
deletion patterns in probe set were seen in 23 (69.7%) <strong>of</strong> cases expanding<br />
from downstream <strong>of</strong> teta gene up to HS-40. Deletion lengths<br />
varied from at least 5.8 kb up to 67.2 kb.<br />
Conclusion: This study, showed using MLPA can help us to increase<br />
accuracy <strong>of</strong> prenatal diagnosis for alpha thalassemia especially when<br />
we face with cases suspected to have large deletion.<br />
P02.172<br />
transfusion dependent H disease: caused by compound<br />
heterozygote <strong>of</strong> two point mutations in alpha globin gene<br />
P. Fouladi 1 , F. Rahiminejad 1 , S. Foroughi 1 , M. Feizpour 1 , M. Masoudifard 1 , S.<br />
Mousavi 1 , M. S. Fallah 1,2 , S. Zeinali 1,3 ;<br />
1 Kawsar <strong>Human</strong> <strong>Genetics</strong> Research Center, Tehran, Islamic Republic <strong>of</strong> Iran,<br />
2 National Institute for Genetic Engineering and Biotechnology (NIGEB), Tehran,<br />
Islamic Republic <strong>of</strong> Iran, 3 CenterDep’t <strong>of</strong> Mol. Med., Biotech Research Center,<br />
Pasteur Institute <strong>of</strong> Iran, Tehran, Islamic Republic <strong>of</strong> Iran.<br />
Thalassemia is the most prevalent genetic disorder. It can be <strong>of</strong> different<br />
severity characterized by an imbalance <strong>of</strong> α and β-globins genes<br />
expression leading to anemia. H disease is the result <strong>of</strong> mutation in 3<br />
alpha globins genes. However, it can also be result <strong>of</strong> coinheritance<br />
<strong>of</strong> 2 point mutations. Here we report a case <strong>of</strong> transfusion dependent<br />
H disease.<br />
DNA was extracted from peripheral blood cells according to the protocols.<br />
Alpha and beta globins gene cluster was investigated using direct<br />
sequencing and real time PCR.<br />
A couple with hematologic picture <strong>of</strong> alpha thalassemia (low MCV,<br />
MCH, and normal HbA2) were referred to our center (i.e. Father with<br />
MCV=73.6 Fl, MCH=21.6 pg, Hb=12.6 g/dl and HbA2=2.7 and the<br />
mother with MCV=73.5 Fl, MCH=22.2 pg, Hb=11g/dl and HbA2=2.2)<br />
They had an 8 years old child with more severe hematological presentation<br />
(i.e. MCV=62.7 Fl, MCH=16.1 pg, Hb=5.1 g/dl and HbA2=2.5)<br />
who received blood transfusion once a month since 7 years old.<br />
Molecular study revealed no mutation in beta globins gene in the child<br />
or the parents. Direct sequencing <strong>of</strong> alpha globins genes showed<br />
2 point mutations in alpha II gene <strong>of</strong> the affected child (i.e. poly A1:<br />
AATAAA>AATAAG and C59: GGC>CGC).<br />
Poly A1 had been inherited from the father and C59 from his mother.<br />
This report indicates the importance <strong>of</strong> alpha globins gene point mutation<br />
and the possible need for prenatal diagnosis. There is a need for<br />
more reports on similar cases to provide a better genetic counseling<br />
for at risk couples.<br />
P02.173<br />
Low HbA2, beta thalassemia; not very prevalent but important<br />
M. Feizpour 1 , R. Vahidi 1 , F. Rahiminejad 1 , S. Frouoghi 1 , P. Fouladi 1 , M. Heidari 1 ,<br />
M. Vahidi 1 , S. Ghahremani 1 , Z. Shahab Movahed 1 , M. Fallah 2,1 , S. Zeinali 3,1 ;<br />
1 Kawsar <strong>Human</strong> <strong>Genetics</strong> Research Center, Kawsar Genomics & Biotech Center,<br />
Tehran, Islamic Republic <strong>of</strong> Iran, 2 National Institute for Genetic Engineering<br />
and Biotechnology (NIGEB), Tehran, Islamic Republic <strong>of</strong> Iran, 3 Dep’t <strong>of</strong> Mol.<br />
Med., Biotech Research Center, Pasteur Institute <strong>of</strong> Iran, Tehran, Islamic Republic<br />
<strong>of</strong> Iran.<br />
Introduction: Beta thalassemia is one <strong>of</strong> the most prevalent monogenetic<br />
disorders in the word and also in Iran. Those who carry one mutation<br />
in beta globin gene usually present with hematologic picture <strong>of</strong><br />
microcytic hypochromic anemia with high HbA2. Mutation in IVSII-nt1<br />
in the beta globin gene is one <strong>of</strong> those, which usually presents with<br />
HbA2 higher than 3.5 g/dl.<br />
Material and methods: Couples referred to us for prenatal diagnosis<br />
(PND) <strong>of</strong> thalassemia were investigated using ARMS PCR technique<br />
and direct sequencing.<br />
Results: From those investigated for beta thalassemia mutation in the<br />
past 8 years, 23 cases (less than 2 %) <strong>of</strong> those with IVSII-nt1 mutation,<br />
had normal HbA2. From which, 9 cases (39.1%) showed high<br />
HbF (>=1.5) (range: 1.6-11.5 g/dl) with hematologic picture <strong>of</strong> MCV:<br />
51-70.4; MCH: 17.1-22.3; Hb: 9.9-14.6 and HbA2: 1.7-3.4. Cases with<br />
low HbF (