European Human Genetics Conference 2007 June 16 – 19, 2007 ...

Cytogenetics
or repeated failure in IVF treatments. The procedures included 9 AS-
(aneuploidy screening), 13 sexing, 19 robertsonian translocation and
20 resiprocal translocation cases. The probes were chosen depending
of the detectable abnormality and all of them were commercially
available. The probes were tested either on the carrier’s lymphocyte
preparates in the cases of balanced translocation or on both spouse’s
lymphocyte preparates. Altogether over 361 embryos and 533 blastomeres
were studied. In these the success rate was 68-82 % depending
from the class of study (AS, sexing, reciprocal or robertsonian translocation).
From the studied embryos the rate of normal embryos were
40 % in As-cases, 58 % (desired=girl) in sexing, 22 % in reciprocal and
41 % in robertsonian translocations. As a result of the IVF-PGD procedures
9 healthy babies have been born. Altogether clinical pregnancy
rate/ET was for AS 37,5%, sexing 30%, robT 21% and balT 21% and
take home baby rate/ET was 12,5%, 30%, 16% and 7%, respectively.
To conclude PGD using FISH is a good option for couples having an
advanced risk for abnormal chromosome content to have a chromosomally
normal child.
P0385. FISH study of 45,X/46,XX mosaicism in patients with
idiopathic premature ovarian failure
b. lakhal, r. braham, h. elghezal, s. mougou, s. hidar, m. chaieb, a. saad;
hopital farhat hached, sousse, Tunisia.
Premature ovarian failure (POF) (OMIM 311360 and 300511) is a disorder
characterized by amenorrhea and elevated serum gonadotrophin
level before 40 years of age that accounts for about 10% of all
female sterility.
Objective: to investigate the implication of low level 45,X/46,XX mosaicism
in the development of idiopathic premature ovarian failure.
Patients: 81 cases of POF-affected women with normal karyotype: 37
with primary amenorrhoea and 44 with secondary amenorrhoea of median
age 25 years (range14 - 41) were analysed.
29 women with normal reproductive histories, having at least one child
were selected as controls. The subjects in this group were approximately
the same age as the patients with POF.
Methods: Interphasic FISH was performed in peripheral blood lymphocytes
using centromeric probe of X chromosome associated with centromeric
probe of chromosome 18 as a control.
Only nuclei with two signals for chromosome 18 were analysed for the
signal pattern of the X chromosome in order to exclude hybridization
artifacts. For each woman, 500 cells were analysed.
Results: In the control group, X chromosome monosomy was detected
in 0.95 to 3.5 % of cells (mean ± 2 SD, 2,33 ± 1,34).
Among patients, 15 (18,5 %) presented a significantly higher percentage
of monosomic cells (>2,33 ± 1,34).
Conclusion: this study indicated that POF in some patients may be
attributed to low-level 45,X/46,XX mosaicism. FISH is more sensitive
than routine chromosome analysis in the detection of low-level X chromosome
monosomy and could be recommended for all POF patients
with normal karyotype.
P0386. An unusual supernumerary marker chromosome
diagnosed following amniocentesis for advanced maternal age:
cytogenetic characterization and phenotype.
A. Schneider1 , C. Abadie1 , A. Chaze1 , G. Lefort1 , P. Blanchet1 , P. Sarda1 , P.
Vago2 , J. Puechberty1 ;
1 2 Service de Génétique Médicale, CHU, Montpellier, France, Service de Cytogénétique
Médicale, CHU, Clermont-Ferrand, France.
A 40-year-old woman was referred for amniocentesis at 16 WG. Amniotic
fluid chromosome studies diagnosed mosaicism for a “de novo”
small supernumerary marker chromosome (SMC) in a male foetus:
47,XY,+mar [13] / 46,XY [8].
The marker was characterized using several molecular cytogenetic
techniques. M-FISH studies indicated that the SMC contained euchromatic
chromosome 1 material and this result was confirmed by positive
whole chromosome 1 painting. FISH with probes for centromeric chromosome
1 and subtelomeric 1p and 1q regions was negative. Microdissection
followed by reverse chromosome 1 painting suggested that
the marker contained pericentromeric 1p and 1q material. In the light of
these results, the parents elected to terminate pregnancy.
Autopsy of the 25 WG foetus showed slight craniofacial dysmorphism,
bilateral camptodactylia and rocker bottom feet, but no organ malformation.
Variable degrees of mosaicism was confirmed by cytogenetic
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analysis on amniotic fluid at termination and on tissues at autopsy
(skin, lung, heart, kidney).The cytogenetic characteristics and partial
trisomy 1 phenotype are discussed.
P0387. Trabecular meshwork structure in Primary congenital
glaucoma and Sturge-Weber syndrome
M. Tanwar 1 , J. Kaur 2 , T. Dada 3 , R. Dada 1 ;
1 Department of Anatomy, All India Institute of Medical Sciences, New delhi,
India, 2 Ocular Biochemistry, R.P. Centre for Ophthalmic Sciences, All India
Institute of Medical Sciences, New delhi, India, 3 Dr. R.P. Centre for Ophthalmic
Sciences, All India Institute of Medical Sciences, New delhi, India.
Primary congenital glaucoma (PCG) is a genetic disease which manifests
at birth or in infancy. PCG characterized by buphthalmos, high
intraocular pressure, corneal edema and photophobia. We had done
electrone-microscopy of seven trabeculectomy samples. In which
one case was PCG with Sturge-Weber syndrome. Sturge-Weber syndrome
is defined as facial port-wine stain in association with ipsilateral
pial,vascular anomalies and inconstant ipsilateral choroidal vascular
lesions with glaucoma. Materials: Seven cases of PCG were enroled in
this study. One case was PCG with Sturge-Weber syndrome Method.
To look for any cytogenetic abnormality, lymphocyte culture was set
and chromosomes were analysed with GTG banding. After informed
consent trabecular tissue were collected to look for any structural
changes in trabecular meshwork. Surgical trabeculectomy tissues
were sent for scanning electrone micropy. For EM study specimens
were fixed in glutraldehyde fixative for 12 hrs and then post fixed in
the osmium tetra oxide at 1% for 2 hrs. Tissue was dehydrated and
mounted and gold plated. Scanning electrone microscopy was done.
Results: Cytogenetically all patients were normal. EM pictures of trabecular
meshwork in all patients showed trabeculardysgenesis and
some unidentified spherical structures of varying size were seen in
case with Sturge-Weber syndrome Conclusion: Due to trabeculardysgenesis
IOP rises in the anterior chamber leading to glaucoma in PCG
cases. In Sturge-Weber syndrome, spherical structures of varying
sizes were seen, may obstructing the normal aqueous outflow. These
structures are occupying the vital space and damaging structure of
trabecular meshwork leading to blockages causing rise in IOP leading
to glaucoma.
P0388. Array-CGH analysis of products of conception with high
density oligonucleotide arrays
G. A. Toruner, D. Streck, J. J. Dermody, M. N. Schwalb;
UMDNJ-New Jersey Medical School, Newark, NJ, United States.
Fifty percent of miscarriages are due to chromosomal abnormalities.
Cytogenetic analysis of products of conception (POC) provides information
about the cause of miscarriage and recurrence risk. This analysis
depends on success in culturing of fetal tissue and preparation of
metaphase cells. Tissue culture failures and suboptimal chromosomal
preparations render the cytogenetic analysis unsuccessful in 10-40%
cases. In addition, selective growth of maternal cells may lead to erroneous
normal findings Comparative genomic hybridization (CGH) is
a laboratory technique that enables assessment of relative DNA copy
number changes between fluorescently labeled patient and control
genomic DNA. Tissue culturing is not necessary for this assay and
it has more resolution than karyotyping. There are some reports of
CGH studies on POC specimens. These studies are either classical
CGH studies or array-CGH studies on BAC arrays. So far no oligonucleotide
array CGH study on POC specimens has been published.
That is the reason we decided to perform a validation array-CGH study
using custom oligonucleotide arrays from Agilent technologies. In this
study, we analyzed 24 POC (fetal tissue and chorionic villi) specimens
with known karyotype results and 6 tissue cultures failures. We were
able to generate array CGH results from all samples. Cytogenetic results
and CGH results were 100% concordant. In addition, previously
undetected deletions were observed in two specimens (16p21 and
22q11.22) were after oligonucleotide array-CGH. These results indicate
that oligonucleotide array-CGH can be used as a rapid diagnostic
tool for analysis of POC.