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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 (

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