2008 Barcelona - European Society of Human Genetics

Prenental diagnostics
service delivery . Recent evidence suggests that there is considerable
variation in the extent to which these guidelines translate into practice .
This is particularly evident in cross-country comparisons . This paper
presents findings from a values survey that assessed the extent to
which informed choice in the context of prenatal testing is a universally
held value .
Method: Values attached to choice in the context of prenatal diagnosis
were assessed among 1) general populations (n=1200) and 2) obstetricians
(n=1117) in Europe (UK, Netherlands, Italy and Greece) and
Asia (China and India) .
Results: Findings from both samples suggest that there is a sharp divide
between first Northern European countries and second, Southern
European and Asian countries in the extent to which choice is valued .
Most respondents from Northern European countries perceived that
undergoing prenatal testing should reflect a parental choice (71%-
86%), compared with a minority from Southern European and Asian
countries (16%-33%) . Comparison across the populations suggests
that health professionals are more strongly in favour of choice than
general populations . Given the political endorsement of informed
choice, the latter may reflect a tendency for professional identities to
dominate over personal values .
Conclusion: Implications of these findings for policy and practice will be
discussed within the framework of the ethical principle of ’autonomy’ .
P03.47
couple’s karyotyping in recurrent miscarriage: A case report
with t(13;14)
S. Shinde, B. B. Ganguly;
MGM Center for Genetic Research and Diagnosis, New Bombay, India.
An individual who is a carrier of a translocation may not have any
problem with their growth, development and health but depending on
the chromosomes involved, they may experience reproductive problems
such as infertility, miscarriage and having a child with abnormal
chromosomal complement . In the present study, chromosome study
was carried out on young couple who was married for 1 .5 yrs and
had three consecutive missed abortions . However, chromosome study
was not carried out in any of the abortus . Couples karyotyping following
PHA-stimulated blood culture detected constitutive abnormality in
husband with 46,XY,t(13;14)(q22 .1;q24 .3) pattern . The translocation
between the two chromosomes was a balanced one with no significant
phenotypic effect . The wife had a normal female karyotype . The possible
genetic make up of the male gametes and subsequently of the
fetus could be: i) both normal 13 and 14, ii) rearranged 13 with normal
14, iii) rearranged 14 with normal 13, and iv) both rearranged 13 and
14 . Mathematically, she has a 1 in 4 (25%) chance of having baby
entirely chromosomally normal and the others will be a translocation
‘carrier’ just like father or carrier of a recombinant 13 or 14 . Therefore,
3/4 of her babies are at risk for being chromosomally abnormal .
These babies could have severe congenital malformations and if they
manage to survive birth and the neonatal period, profound metabolic
disturbances and mental retardation could persist life long . However,
prenatal diagnosis in CVS or amniotic fluid must be carried out for
evaluation of chromosomal composition in fetus and obstetric management
accordingly .
P03.48
Triploidy identified through Maternal Serum Screening in
second trimester
F. Behjati 1,2 , I. Bagherizadeh 2 , M. Oveisi 2 , Z. Hadipour 2 , A. Saremi 2 , Y. Shafaghati
1,2 ;
1 Genetics Research Center, University of Social Welfare and Rehabilitation
Sciences, Tehran, Islamic Republic of Iran, 2 Dept. of Medical Genetics, Sarem
Women’s Hospital, Tehran, Islamic Republic of Iran.
Amniocentesis was carried out at 17 weeks gestation on a 27 years old
woman following an abnormal maternal serum screening test (MSS) .
MSS test was carried out primarily to estimate the risk of trisomy for
chromosomes 21 and 18 . The maternal serum markers used were
alpha-fetoprotein (AFP), human chorionic gonadotrophin (HCG), and
unconjugated estriol (UE3) together with maternal age . The fetus was
identified as screen-positive for Edward’s syndrome (trisomy18), with
low UE3, normal AFP and hCG levels . The calculated risk for trisomy
18 was more than 1:50 .
To identify any possible chromosomal abnormality, cytogenetics inves-
tigation was carried out on amniotic fluid sample. The fetus’s kayotype
was triploid with 69, XXX chromosome complement in all the
metaphase spreads obtained from three different cultures, using GTG
banding technique . Upon termination of the fetus, gross abnormalities
indicative of triploidy were present in the fetus .
This is one of a few cases reported so far where abnormal maternal
serum screening indicative of trisomy 18, ends up as a triploid fetus .
Maternal serum screening is an essential approach for detecting chromosome
abnormality prenatally, and thus helping with prevention of
the birth of a genetically abnormal fetus .
P03.49
A new prenatal diagnosis of Nager syndrome on monochorionicbiamniotic
twin pregnancy
H. Ansart-Franquet 1 , V. Houfflin-Debarge 1 , J. Ghoumid 1 , N. Pasz 1 , L. Devisme
2 , S. Manouvrier-Hanu 1 , J. Andrieux 1 , M. Holder-Espinasse 1 ;
1 Jeanne de Flandre, Lille, France, 2 Centre de Biologie Pathologie, Lille, France.
The Nager syndrome, also termed preaxial acrofacial dysostosis, is a
rare condition characterised by limb and facial deformities . Limb anomalies
consist of hypoplasia or absence of radius, radioulnar synostosis,
and hypoplasia or absent thumbs . The mandibulofacial dysostosis is
characterised mainly by severe micrognatia and malar hypoplasia .
Since its first description in 1948, more than 80 cases have been reported
in the literature, although there are only two reports of prenatal
diagnosis . We report here a further case of Nager syndrome diagnosed
at 22 weeks of gestation in a monochorionic biamniotic twin pregnancy
. The prenatal diagnosis was performed on ultrasound because of
severe microretrognathia and significant forearm shortening on both
foeti . Termination of pregnancy was performed at 25 WG . Chromosomes
were normal 46XY. The pathology report confirmed the diagnosis
of Nager syndrome in both twins . Growth discordance was noted
between the fetuses . Both presented a large cleft palate, ear dysplasia
and a severe microretrognathia . They had bilateral thumb agenesis
with single palmar crease. The X-ray confirmed the microretrognathia.
One foetus had bilateral radioulnar synostosis with hypoplasia of the
right radius, and bilateral thumb agenesis . The other twin presented
bilateral thumb agenesis too, but only a partial radioulnar synostosis
on the left side . A CGH-array analysis on fetal DNA is pending.
P03.50
cytogenetic analysis of chorionic villi samples (cVs) in missed
abortions
K. Sentija, Z. Duic, I. Krivak Bolanca, S. Katalenic Simon;
University Clinic Merkur, Zagreb, Croatia.
The aim of our study was to analyse the frequency and type of chromosomal
aberrations of chorionic villi samplings (CVS) in patients with
missed abortion, performed in our clinic during last three years .
Methods: CVS analyses obtained by transabdominal biopsy in first
and second trimester of 57 pregnant women with ultrasonographic
evidence of missed abortion were performed . For chromosome analysis
conventional cultures of CVS and GTG-banding techniques were
used .
Results: Of total 579 CVS analysed, 57 CVS were performed for
missed abortion . The mean maternal age was 35,86 (22-46) years,
and mean gestational week was 9,75 (8-16) . Fetal karyotyping was
successful in 54 cases, while 3 cases were excluded from study for
low proliferative activity . Of 54 analysed, 36 (66 .66%) cases had an
abnormal karyotyp, while no cromosomal abnormalities could be diagnosed
in 18 (33 .33%) cases . Of 36 abnormal karyotyps, predominant
abnormality were autosomal trisomies in 22 (61,11%) cases, including
various chromosome groups (B,C;D,E,G), most of them represent
nonviable defects . Follows 6 (16,65%) polyploidies and 4 (11,11%)
X monosomies (46,XO) . Relatively rare type of double abnormality
in 2 cases (5,55%) (48,XY;D14+,E17+; 48XX;C7+,D13+) were observed
. Mosaicism (46,XY/47,XY) was present in one case (2 .77%)
where autosomal trisomy could not be determinated . Translocation
(46,XY)t(D13,D14) was also present only in one (2 .77%) case .
Conclusion: Alghtough CVS analysis in our study did not exclud normal
karyotype, our results suggest that missed abortion is strongly associated
with chromosome abnormalities . The factors responsible for
missed abortion with a normal karyotype are presently unknown and
require further study .