2009 Vienna - European Society of Human Genetics

Prenatal and perinatal genetics
MCC contamination were performed by comparing the peak area of
the informative maternal allele to the unique fetal allele; the new CE
instrument provided adequate sensitivity for detecting a synthetic MCC
control at a level of 1% or greater. Further, we discuss common pitfalls
to the analysis of MCC results such as broad peak errors, allelic drop
out (ADO), preferential allelic amplification, and the influence of stutter
peaks.
P05.18
Expression Profiling of Placental microRNAs in Preeclamptic
maternal Plasma
T. Gunel 1,2 , I. Kalelioglu 3 , P. Akcakaya 1 , R. Has 3 , H. Ermis 3 , K. Aydınlı 4 ;
1 Istanbul University, Faculty of Science, Department of Molecular Biology and
Genetics, Istanbul, Turkey, 2 Istanbul University, Research and Application
Center for Biotechnology and Genetic Engineering 34134, Vezneciler/Istanbul,
Istanbul, Turkey, 3 Istanbul University, Faculty of Medicine, Istanbul-TURKIYE.,
Istanbul, Turkey, 4 Istanbul University, Cerrahpaşa Faculty of Medicine, Istanbul-
TURKIYE., Istanbul, Turkey.
Preeclampsia is a potentially dangerous disorder specific to the second
half of pregnancy, affecting about 2.5-3% of women. It is the most
frequent pregnancy associated disorder and still a leading cause of
maternal and perinatal mortality and morbidity and preterm birth. Preeclampsia
starts with placental dysfunction in the first trimester. Despite
extensive research on preeclampsia during the last decades, the
underlying pathogenetic mechanisms remain unclear.
Identification of placental products rather than cells in the maternal
circulation has taken a drastic turn for the better by the observation
that cell-free DNA and RNA originating from the placenta circulates
in a protected form in the maternal blood and can be obtained easily
from the maternal plasma. Recent studies on microRNAs (miRNAs)
offer possibilities for developing another class of molecular markers.
miRNAs are short (19-25 nucleotides), single-stranded, and nonprotein-coding
RNAs that regulate gene expression by binding to the 3’
untranslated region of the target mRNAs.
In this study, it is aimed that detection of miRNAs which have the different
expression profile in maternal plasma in preeclamtic pregnants
compare to healthy pregnants. In the content of study, miRNA extraction
from maternal plasma of 20 pregnants with preeclampsia and 20
non-preeclampsia healthy pregnants, detection of expression differences
by the use of microarray and expression analysis of detected
miRNAs by quantitative real time pcr.The comparison of the collection,
isolation and concentration approaches as well as detection can be
observed in detail on our poster presentation.
P05.19
study of the natridiuretic peptide precursor gene (tttc) repeats
in essential hypertension and preeclampsia
G. Szabo, T. Varkonyi, B. Stenczer, A. Molvarec, J. Rigo Jr, B. Nagy;
Semmelweis University, Budapest, Hungary.
Background: Lately a novel variable tandem repeat polymorphism
(TTTC) in the 5’-flanking region of the natriuretic peptid precursor B
gene (NPPB) was discovered, which was associated with essential
hypertension. It has not been studied in preeclamsia (PE). PE is a
serious complication of pregnancy with hypertension and proteinuria,
developing in the second half of the pregnancy. We decided to determine
the tandem repeats of the NPPB gene in preeclampsia.
Method: DNA was isolated using High Pure PCR Template Preparation
kit (Roche, Germany) from blood samples of 28 healthy pregnants, 17
pregnants with essential hypertension and 26 preeclamptic patients.
We used fluorescent PCR and DNA fragment analysis for the detection
of the NPPB gene’s tandem repeat units on ABI 3130.
Results: We found that the distribution of the TTTC repeat number is
giving mainly two groups, one at 11 and the other at 16. We found low
frequency of the high number of repeats (n=16) in the control healthy
group (21.4%), while it was higher in essential hypertension (32.3%)
and preeclamptic patients (32.6%). Conclusion: We found higher frequency
of the high TTTC repeat (n=16) alleles of the NPPB gene in
essential hypertension and preeclampsia. We continue our investigation
to find out the role of this polymorphism in the development of
hypertension.
P05.20
Identification of UGT A (tA) 5 and (tA) 8 alleles in slovenian
newborns with pathological unconjugated hyperbilirubinemia
B. Ostanek 1 , D. Furlan 2 , B. Bratanič 3 , M. Zupančič 3 , J. Lukač Bajalo 1 ;
1 Faculty of Pharmacy, Department of Clinical Biochemistry, Ljubljana, Slovenia,
2 General Hospital Novo mesto, Diagnostic Laboratory, Novo mesto, Slovenia,
3 University Medical Centre Ljubljana, Pediatric Department, Ljubljana, Slovenia.
Unconjugated hyperbilirubinemia is a common finding during the neonatal
period and can sometimes lead to severe consequences such
as bilirubin encephalopathy. Increased number of TA repeats in the
promoter region of the bilirubin UDP-glucuronosyltransferase gene
(UGT1A1) results in decreased bilirubin conjugation and is the principal
cause of Gilbert’s syndrome in Caucasians.
The aim of the present study was to investigate whether UGT1A1(TA) n
polymorphism was related to pathological hyperbilirubinemia of unexplained
aetiology in Slovenian newborns.
Single-strand conformation polymorphism analysis was used to genotype
147 consecutive newborns with unexplained jaundice (total serum
bilirubin over 220 μmol/L) admitted to the Neonatal unit of University
Medical Centre Ljubljana.
The frequencies of genotypes were as follows: (TA) 6/6 (42.9%), (TA) 6/7
(37.4%), (TA) 7/7 (16.3 %), (TA) 5/6 (2.0%), (TA) 5/7 (0.7%) and (TA) 6/8
(0.7%). The frequency of (TA) 7/7 genotype, which is characteristic for
Gilbert’s syndrome did not differ from that of the healthy Slovenian
population (p>0.05). However, in neonatal hyperbilirubinemia group
males had higher frequency of (TA) 7 allele than females (p=0.045). It
is interesting that there were 69.4 % males and 30.6% females in our
hyperbilirubinemia group.
In conclusion, frequency of UGT1A1(TA) n polymorphism genotypes
was determined for the first time in Slovenian newborns with pathological
hyperbilirubinemia. The extremly rare (TA) 5 and (TA) 8 alleles in
Caucasians were found also in Slovenians. Our results suggest that
male newborns with (TA) 7 allele have an increased risk to develop
pathological neonatal hyperbilirubinemia.
P05.21
Recurrent progressive non-immune hydrops foetalis: better
think of mucopolysaccharidoses type Vii/ beta-glucuronidase
deficiency/ GUSB gene defect
S. G. M. Frints 1,2 , Y. Arens 1,2 , J. Bakker 3 , J. Huijmans 4 , S. Stevens 5 , J. Engelen
5 , R. Blok 2,6 , J. Nijhuis 7 , C. Willekes 7 , A. ten Haaft 8 , Y. Henskens 8 , A. Cleven 9 ,
M. Baldewijns 9 , W. Lissens 10 , C. E. M. de Die-Smulders 1,2 ;
1 Prenatal Diagnosis and Therapy, Department of Clinical Genetics, Maastricht
University Medical Center, Maastricht, The Netherlands, 2 School for Oncology
and Developmental Biology, GROW, University of Maastricht, Maastricht, The
Netherlands, 3 Laboratory for Inherited Metabolic Disorders, Department of
Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands,
4 Department of Clinical Genetics, Erasmus University Medical Center,
Rotterdam, The Netherlands, 5 Cytogenetic Laboratory, Department of Clinical
Genetics, Maastricht University Medical Center, Maastricht, The Netherlands,
6 DNA laboratory, Department of Clinical Genetics, Maastricht University Medical
Center, Maastricht, The Netherlands, 7 Prenatal Diagnosis and Therapy,
Department of Obstetrics & Gynaecology, Maastricht University Medical Center,
Maastricht, The Netherlands, 8 Department of Hematology, Maastricht University
Medical Center, Maastricht, The Netherlands, 9 Department of Pathology, Maastricht
University Medical Center, Maastricht, The Netherlands, 10 Center of Medical
Genetics, University Hospital Brussels, Brussels, Belgium.
Mucopolysaccharidosis type VII/ beta-glucuronidase is an autosomal
recessive lysosomal storage disease. The phenotype is highly variable,
ranging from severe lethal non-immune hydrops foetalis to mild
forms with survival into adulthood. We describe a non-consanguineous
couple, first presented with non-immune hydrops foetalis, ascites
and clubfeet in the fourth pregnancy at 20 weeks of gestation. They
had one early miscarriage and two healthy children. Prenatal diagnosis
showed (familial) 45,XX, der(14;15)(q10;q10) karyotype with de
novo RAI1 locus duplication MLPA detected. Uniparental disomy 14
and 15 were excluded. The pregnancy was terminated at 26 weeks
of gestation. Lysosomal enzyme investigations in amniotic fluid were
not conclusive and 5% recurrence risk for hydrops foetalis was counselled.
In the fifth pregnancy prenatal diagnosis revealed a 46,XY
karyotype without RAI1 duplication. However, ultrasound investigation
showed again a progressive hydrops foetalis. Cultured amniocytes