2008 Barcelona - European Society of Human Genetics

Cytogenetics
of spermatogenesis in Yq deleted patients are still largely unknown . In
this study we analyzed by microarray technology the testis expression
profiles of patients with idiopathic infertility, patients carries of AZFc
deletion and controls (patients with obstructive azoospermia), in order
to obtain useful information about the specific genes involved in
each different pathological condition . Using the hierarchical clustering
average method in 27 microarray experiments we identified in AZFc
deleted patients two main gene clusters showing different expression
patterns as compared to normal controls and patients with idiopathic
infertility . Analysis of these gene clusters using IPA software revealed
an interesting down-regulated gene network directly related with spermatogenesis,
with the most significant network centred around YBX2
gene (Y box binding protein 2), involved in RNA storage during gametogenesis
. This alteration is responsible for the downregulation of the
protammine1 and 2 genes evidenced in the same nethwork analysis .
In the expression profiles comparative analysis between controls and
AZFc deleted patients we also observed an interesting downregulation
of the CREM pathway, which is a master controller gene for spermatogenesis
. This suggests that impairment of RNA storage and dysregulation
of the CREM pathway could represent two of the biological
mechanisms underlying spermatogenesis failure in patients with Yq
microdeletion .
P02.234
Identification candidate genes and proteins involved in male
infertility through proteomic analysis of human sperm proteins
R. Oliva 1 , S. de Mateo 1 , J. Martínez-Heredia 1 , T. Botta-Orfila 1 , S. Blescia 1 , J.
Oriola 1 , J. Estanyol 2 , J. Ballescà 3 ;
1 Human Genetics Research Group, Biochemistry and Molecular Genetics
Service, Faculty of Medicine, Univ. Barcelona, and Hospital Clínic, Barcelona,
Spain, 2 Proteomics Unit, Faculty of Medicine, Univ. Barcelona, Barcelona,
Spain, 3 Institut Clínic de Ginecologia, Obstetricia i Neonatologia, Hospital
Clinic, Barcelona, Spain.
Proteomics offers at present the opportunity to compare the relative
abundance of the different proteins present in patients and controls
with the potential to identify diagnostic markers and candidate proteins
to be used in genetic association studies . Towards this goal the proteins
present in the sperm cells from sperm samples from infertile patients
and from semen donors were analyzed by 2D gel electrophoresis . In
each of the 2D maps the intensity of 101 spots previously identified
by MALDI-TOF analysis was measured . Additionally, the protamine
content and DNA integrity were also determined in each independent
sample . Several interesting proteins such as transcription factors, prohibitin,
heat shock and proteasome proteins have been identified. Of
relevance the expression of an important number of proteins (55 different
2D spots) correlated in independent sperm samples at high statistical
significance. Some of the proteins have been found to correlate
with DNA integrity and protamine content in infertile patients . Therefore
this is proving to be a useful approach leading to the identification of
candidate proteins and therefore candidate genes which may harbour
mutations or polymorphisms involved in the pathogenic mechanisms
present in infertile patients . Supported by BMC006-03479 .
P02.235
Primary male infertility in Izmir / Turkey: a cytogenetic and
molecular study of 187 infertile turkish patients
H. Akin, H. Onay, E. Turker, F. F. Ozkinay;
Ege University Medical Faculty Medical Genetics Department, İzmir, Turkey.
Infertility is an important health problem affecting 10-15% of couples .
The contribution of male factors to patients is about 30-50% . The
main genetic factors in male infertility are somatic chromosomal abnormalities
and Y chromosomal microdeletions within Yq11 region .
The genes which control spermatogenesis are located in Yq11 region
and are known as azoospermia factor genes (AZF) .The AZF region
has 3 non-overlapping loci-AZFa, AZFb, AZFc which are required for
normal spermatogenesis . All these genes are expressed in testicular
tissue showing that they play roles in human spermatogenesis . Here,
we aimed to detect somatic cytogenetic abnormalities and AZF microdeletions
in a sample of 187 Turkish infertile men and to evaluate the
frequencies and the characteristics of our primary male infertility data
in order to perform appropriate genetic counseling .
Cytogenetic study revealed chromosomal abnormality in 9 subjects
(4 .8%) . In remaining 178 subjects, 7 subjects (3 .93%) were detected
to have Y chromosome microdeletions . The AZFc region was the most
frequently involved region in affected subjects . One of these subjects
showed microdeletion in all 3 regions(AZFa, AZFb, AZFc) and one
subject had microdeletions in both AZFb and AZFc regions . Other 5
subjects had microdeletions in only AZFc region . All subjects having
microdeletion were azoospermic .
In conclusion, cytogenetic and molecular study should be performed
to obtain reliable genetic information for the genetic counseling of primary
infertile man . Y chromosome microdeletion diagnosis is useful
in decision making for assisted reproductive techniques because the
association between some deletions and residual spermatogenesis
capacity has been proven .
P02.236
Oxidative stress and mitochondrial DNA mutations in
Oligoasthenoteratozoospermic patients
S. Venkatesh, R. Kumar, M. B. Shamsi, M. Tanwar, D. Pathak, R. Dada;
Laboratory for Molecular reproduction and Genetics, Department of Anatomy,
All India Institute of Medical Sciences, New Delhi, India.
Excess production of reactive oxygen species (ROS) establishes oxidative
stress (OS) in the semen . Mitochondria are suspected to be the
source and target of ROS where mutation in mitochondria can impair
the formation/function of mature spermatozoa . So the present study
was aimed to correlate the oxidative stress and mtDNA mutation with
the sperm parameters of infertile patients . Study includes 62 infertile
subjects and 30 fertile controls attending AIIMS, New Delhi, India .
Complete semen analysis was performed according to WHO criteria
(1999) . OS was evaluated by malonaldehyde estimation and sperm
mitochondrial DNA mutations by standard PCR-DNA sequencing . Infertile
group showed significantly (p< 0.001) higher MDA levels (0.18 ±
0 .03 nmol / 10 6 spermatozoa) compared to fertile controls (0 .10 ± 0 .02
nmol/ 10 6 spermatozoa) . The mean sperm count of infertile group was
12 .78 ± 11 .81 x 10 6 /ml, whereas the fertile group had 55 .73 ± 20 .57
x 10 6 /ml . DNA sequencing revealed that 66% (n=41) of the infertile
group harboured one or more mutations (T4672A, C10165T, C10207T,
A10470G, T13946A) in the mitochondrial genome where no mutations
were detected in the fertile group inspite some common nucleotide
changes (A750G, A4769G) in both the groups . All the mean sperm
parameters of infertile subjects were negatively correlated with the
malonaldehyde level . Higher MDA levels in the infertile subjects compared
to the controls may be correlated with the change in the gene
sequence of sperm mtDNA of infertile subjects . Thus mtDNA mutation
harboured in the infertile groups may be due to oxidative stress .
P02.237
Mutations and polymorphisms in the cystic fibrosis gene in men
with severe oligozoospermia.
M. Teder-Laving 1 , M. Punab 2 , E. Oitmaa 3 , A. Belousova 4 , K. Haller 5,6 , O. Poolamets
2 , E. Raukas 7 , A. Metspalu 8 , A. Salumets 4,9 ;
1 Estonian Biocentre, Tartu, Estonia, 2 Andrology Unit of Tartu University Hospital,
Tartu, Estonia, 3 Asper Biotech, Tartu, Estonia, 4 Institute of Molecular and
Cell Biology, Department of Biotechnology, University of Tartu, Tartu, Estonia,
5 Department of Obstetrics and Gynaecology, University of Tartu,, Tartu, Estonia,
6 Institute of General and Molecular Pathology, Department of Immunology,
University of Tartu, Tartu, Estonia, 7 United Laboratories, Tartu University
Hospital, Tartu, Estonia, 8 Institute of Molecular and Cell Biology, Department
of Biotechnology, Tartu, Estonia, 9 Department of Obstetrics and Gynaecology,
University of Tartu, Tartu, Estonia.
Background: Majority of male cystic fibrosis (CF) patients are infertile
because of congenital bilateral absence of vas deferens (CBAVD) .
In addition, male infertility as a result of isolated CBAVD is also recognized
as a primary genital form of CF. Mutations in cystic fibrosis
transmembrane conductance regulator (CFTR) gene have been found
in more than 85% of CBAVD cases . Possible involvements of CFTR
mutations in other forms of male infertility have been suggested but
remain controversial . In sperm, CFTR may be important in transport
of various anions and sperm capacitation, hence making it possible
that certain CFTR mutations may lead to reduced sperm fertilizing capacity
and male infertility in other forms of male infertility rather than
CBAVD .
Objective: To compare the frequency of CFTR gene mutations between
oligozoospermic and healthy fertile men .
Materials and Methods: The study populations consisted of 124 oligo-