2008 Barcelona - European Society of Human Genetics

Clinical genetics
In Cyprus, the mutation IVSI-110 accounts for 81% of all the cases .
Therefore, the development of a non-invasive method for the Cyprus
population is based on the detection of paternally inherited Single
Nucleotide Polymorphisms (SNPs) as well as the direct detection of
paternal beta-thal mutations .
Eleven SNPs with high degree of heterozygosity in the Cypriot population
were selected and analyzed on 34 families and the informative
SNPs were determined. In order to find a higher number of informative
SNPs, the degree of heterozygosity in the Cypriot population was determined
for 130 SNPs on 75 random samples using the Sequenom®
MALDI-TOFF Mass Array genotyping analysis .
One of the approaches that are being developed is the Arrayed Primer
Extension (APEX) method on the Genorama® QuattroImager . We
developed a DNA chip called “thalassochip” that contains 60 beta-thal
mutations and 10 SNPs linked to the beta-globin locus . The APEX assay
was applied on maternal plasma of 7 families using the informative
SNPs; paternal allele of the fetus was non-invasively detected in
5 families .
Peptide Nucleic Acids (PNA) probes are used to suppres amplification
of the maternal allele and unmask the fetal allele. The efficiency
of PNA-mediated PCR clumping technique was tested on APEX and
sequencing analysis .
P01.011
Delineation of deletions in beta globin gene cluster causing
HPFH in iran
M. T. Akbari 1 , M. T. Akbari 2 , B. Keikhaee 3 , S. Zare-Karizi 2 , M. Karimipour 4 , L.
Mottaghi 2 ;
1 Tarbiat Modares University, Tehran, Islamic Republic of Iran, 2 Tehran Medical
Genetics Laboratory, Tehran, Islamic Republic of Iran, 3 Ahwaz Medical Sciences
University, Ahwaz, Islamic Republic of Iran, 4 Pasteur Institute of Iran,
Tehran, Islamic Republic of Iran.
Background: Hereditary persistence of fetal hemoglobin (HPFH) and
äâ thalassemia are heterogeneous disorders characterized by elevated
levels of fetal hemoglobin (HbF) in adult life . The distinction
between these conditions is subtle and is made on clinical and hematological
grounds . Most HPFHs are caused by large deletions involving
a variable extent of DNA segment on the beta-globin gene cluster .
There are eight common forms of such deletions reported in different
populations . In this study ten unrelated individuals with characteristic
HPFH hematological profile were investigated to delineate their betaglobin
gene cluster deletions .
Aims and objectives: Molecular analysis of 10 Iranian patients with
low MCV and MCH, Normal HbA2 and high level of HbF (5%-15%)
was carried out . They were referred from primary health care centers
involving in the national prevention program for thalassemia .
Materials and methods: After obtaining informed consent, genomic
DNA was extracted from peripheral blood . Multiplex gap PCR method
was exploited for characterizing of 8 different deletions in beta-globin
cluster causing delta-beta thalassemia or HPFH .
Results and discussion: Seven individuals from this group were shown
to be heterozygous for the 13 .4 kb Sicilian deletion, two were heterozygous
for the Asian-Indian form of inversion-deletion Ggama(Agamadelta-beta)
0 thalassemia and mutation for one of them was not identified.
So far three types of deletional mutations in Iranian patients have
been reported. These results confirm the previous findings.
P01.012
Reporting of Beta talassemia mutations frequency by DNA
sequencing analysis in iran
M. Sajedifar 1,2,3 , M. Moshirazin 1,2 , S. Mousavi 1,2 , Z. Shahab Movahed 1,2 , A. Joodaki
1,2 , S. Zeinali 1,2,4 ;
1 Kawsar Human Genetic Reaserch Center- KGBC, Tehran, Islamic Republic
of Iran, 2 Medical Genetics Lab of Dr Zeinali, Tehran, Islamic Republic of Iran,
Tehran, Islamic Republic of Iran, 3 Researchers Club of research and science
branch of Islamic Azad University, Tehran, Islamic Republic of Iran, 4 Human
Genetics Unit, Dept of Biotech Pasteur Institute, Tehran, Islamic Republic of
Iran, Tehran, Islamic Republic of Iran.
Beta-thalassemia is the most prevalent genetic disorder in Iran . In order
to control this autosomal recessive disorder several plans are in
effect, including premarital genetic counseling and blood tests . Our
unit has been chosen as National Reference Center for Prenatal Diagnosis
. We are actively involved in prenatal diagnosis, carrier detection
and molecular analysis of mutations in β-globin gene. We have started
to perform DNA sequencing for all samples especially for unknown
cases since July of 2005. We find that DNA sequencing is very suitable
and informative for screening of mutations except deletions . DNA
samples are usually tested for mutations like IVS-II-I, IVSI-5, IVS-I-
110, codon 5, codon 17,codon 41/42(-TTCT) and many common mutations
and deletions . We have decided to use a comprhensive mutation
screening apprach and sequenced the gene by 3130 Genetic
Analyzer . After detection of 2654 sequences in 2 years, we have found
very different abundance for these mutations:-28tata box,-29tata box,-
30 tata box,-88,-101,codon 2,codon15,codon36-37,codon39,codon82-
83,codon121,IVS-I-5,IVS-I-110,IVS-II-1,IVS-II-666 and more than 35
other mutations .
P01.013
molecular characterization of beta-thalassemia intermedia in
Antalya population, turkey
I. Keser 1 , A. D. Sanlioglu 1 , E. A. Aydemir 1 , A. Yesilipek 2 , D. Canatan 3 , G. Luleci
1 ;
1 Akdeniz University, Medical Faculty, Department of Medical Genetics, Antalya,
Turkey, 2 Akdeniz University, Medical Faculty, Department of Pediatrics, Antalya,
Turkey, 3 The State Hospital, Thalassemia Center, Antalya, Turkey.
Beta-thalassemia intermedia (Beta-TI) is a term used to define a group
of patients with β-thalassemia in whom the clinical severity of the disease
is somewhere between the mild symptoms of the β-thalassemia
trait and the severe manifestations of β-thalassemia major. Beta-TI
shows both clinic and genetic heterogeneity . The purpose of this study
was to analyze the relation between the genotype and phenotype in
Turkish patients with beta-TI living in Antalya, Turkey . A total of 32
patients with beta-TI were evaluated for mutations and their clinical
findings. Eight different mutations [-30 (T-A), Cod 3 (+T), Cod 8(-AA),
Cod 39 (C-T), IVS1 .6 (T-C), IVS1 .110 (G-A), IVS2 .1 (G-A), IVS2 .745
(C-G) ] were found in our study . The IVS1 .6 (T-C) was the commonest
beta-mutation, occurring in both homozygous state in five patients and
compound heterozygous state in eight patients . The IVS2 .1 (G-A) was
the second beta-mutation in eight patients as homozygous state in two
patients . In a family with beta-thalassemia, two sibs were compound
heterozygote for IVS2 .1(G-A) and IVS1 .110 (G-A) . One of them was
female with beta-TI, while other was male with beta-thalassemia major.
In addition, our findings were compared with literature and the mutation
profile in beta-TI patients was differently found in our population
than others. In conclusion, our data suggest that modifier genes should
be screened together with beta-globin gene mutations in patients with
beta-thalassemia intermedia to give correct genetic counseling and to
provide the effective treatment .
P01.014
Effect of α-gene numbers and XmnI Polymorphism on the
phenotype of HbE/β thalassemia patients
V. Sharma, B. Kumar, R. Saxena;
All India Institute of Medical Sciences, New Delhi, India.
introduction: HbE [β26 (B8) Glu-Lys] with β thalassemia (HbE/β thalassemia)
results in a clinically severe condition . HbE/ß thalassemia
has a very variable clinical phenotype . Some of the possible explanations
for the observed variable clinical severity are coinheritance of
α-thalassemia and XmnI polymorphism. Objective: To determine the
frequency of XmnI polymorphism, α deletion and triplication in HbE/
β thalassemia patients and to study their effect on the phenotype of
Patients . material and methods: Subjects were 85 HbE/ßthalassemia
patients .Patients were divided into three subgroups according to
a scoring system based on seven clinical criteria as mild (score 0-3 .5),
moderate (score 4-7) and severe (score7.5-10). α deletions and XmnI
polymorphism were studied by GAP-PCR and PCR-RFLP respectively
. Results: α deletion was found in 18 (21.2%) out of these 18 patients
12(11 αα/-α 3 .7 & 1 αα/--SA) were from Gp1 and 6(αα/-α 3 .7 ) were from
Gp2 .α triplication was found in 7(8.2%) out of these 7 patients 5 were
(αα/ααα anti-3 .7 ) from Gp3 and 2 were (αα/ααα anti-3 .7 )from Gp 2 .XmnI was
found in 53(62 .3%), out of which 43 were heterozygous(+/-) &10 were
homozygous(+/+) .XmnI +/+ was present in 6 Gp1 & 4 Gp2 patients,
while XmnI +/- was present in 8 Gp1 ,15 Gp2 & 20 Gp3 patients . conclusion:
Patients with coexisting α deletion, required lesser transfusions
and had less severe phenotype while patients with α triplication
were on frequent transfusions and had severe phenotype . XmnI poly-
0