2009 Vienna - European Society of Human Genetics

Cytogenetics
For further characterization of the derivative chromosome we will apply
array-CGH analysis. This may help identification of genes, dosage
abnormalities of which may result in neurological and developmental
disorders.
P03.127
Report of a familial inversion
F. Nasiri, M. Rahnama, F. Mortezapour, F. Manoochehri, F. Razazian, M. Zamanian,
F. Mahjoubi;
Iranian blood transfusion organization, Tehran, Islamic Republic of Iran.
A couple was referred to us for chromosomal analysis because they
had a child with growth delay.
Lymphocyte cultures from the patients were set up in RPMI1640 supplemented
with 20% FBS. High resolution chromosome banding was
performed.
In all cells analyzed an inversion on the p arm of chromosome (1) of
both husband and wife was detected. The karyotypes were assessed
as 46,XX,inv(1)(p31;p34.3) and 46,XY,inv(1)(p31;p34.3).
Therefore chromosome analysis was recommended for their affected
child. Interestingly the same inversion was found for the affected child,
and indeed one of the sisters of this male patient had the same inversion.
The phenotypic abnormalities presented in this child could be caused
by the possible deletion of the important genes located at the breakpoint
regions or it could just be a coincidence.
Chromosome study for all the siblings of this couple was recommended.
In addition prenatal diagnosis for the future pregnancies of the all
the carriers of this inversion was recommended.
P03.128
Unusual cases of trisomy 9p and tetrasomy 9p Detected
Postnatally
K. Adamová 1 , P. Čapková 1 , M. Holzerová 2 , M. Jarošová 2 , V. Curtisová 1 , A.
Šantavá 1 ;
1 Department of Medical Genetics and Foetal Medicine, University Hospital and
Palacky University, Olomouc, Czech Republic, 2 Department of Haematology,
University Hospital and Palacky University, Olomouc, Czech Republic.
Isochromosomes of autosomes are relatively rare chromosomal aberrations.
Isochromosome formation results when one arm of a chromosome
is lost and the remaining arm is duplicated. An isochromosome
has morphologically identical genetic information in both arms. The
clinical impact on patient depends on the type of the chromosome and
the length of the duplicated segment. Supernumerary isochromosomes
may result in autosomal trisomy or much rarely in tetrasomy which has
been described only in a limited number of chromosomes.
We describe two cases of aneuploidy 9p both of which involved isochromosome
9p.
The first case is a trisomy 9p (Rethore syndrom) in a form of isochromosome
9p detected in a child together with translocation of 9q to
chromosome 11 confirmed by FISH and CGH.
The second case describes newborn with severe malformations. Postnatal
examination revealed supernumerary chromosome 9 determined
by FISH as isodicenric chromosome 9p.
P03.129
Jacobsen syndrome : about three tunisian cases
l. ben jemaa, m. chaabouni, m. kssentini, h. jilani, i. ouertani, f. maazoul, r.
mrad, h. chaabouni;
service des maladies congénitales et héréditaires, tunis, Tunisia.
Jacobsen syndrome is caused by terminal deletions of the long arm of
chromosome 11, typically in sub-band 11q23.3 with deletions extending
to the telomere.
The phenotype severity depends on the deletion shape witch leads
to several dysmorphic features , heart defects and Paris-Trousseau
syndrome.
The first case was a 4-years old boy with dysmorphic features, cardiac
defect and language delay. The second case was a two-and-a-half
year old boy who was referred to our consultation for dysmorphic features,
language delay, ventricular septal defect and undescent testes.
The third case was an eight-mounth-year old boy, he was referred for
malformatif syndrome, he had oesopahagus atresie, cardiac defect
and clinodactyly of fifth fingers.
All patients have dysmorphic features compatible with Jacobsen syn-
drome.
The three patients have cardiac defect , the first case have a minor
form of Ebstein disease , the second one has ventricular septal defect,
the third one has auricular and ventricular septal defect and pulmonary
stenosis.
None of our patients has thrombocytopenia.
All the deletions included band q23.3 of the long arm of chromosome
11 and are de novo.
The 11 q terminal deletion disorder appear to be a contiguous deletion
gene disorder With molecular cytogenetic we will better delineate the
critical regions and precise the correlation genotype phenotype and
the identification of candidate causing genes.
P03.130
Variable phenotype of 18p monosomy in two patients
A. Singer 1 , J. Rosenblat 2 , C. Vinkler 3 ;
1 Genetic Institute, Barzilai Medical Center, Ashkelon, Israel, 2 Genetic Institute
Kaplan Medical Center, Rehovot, Israel, 3 Genetic Institute, Wolfson Medical
Center, Holon, Israel.
Monosomy 18p ( de Grouchy Syndrome 1), is a rare disorder. The
incidence is around 1:50,000 live born infants. The phenotype includes
mild to severe mental retardation, speech delay and short stature.
Various phenotypic expressions have been attributed to the deleted
regions on the short arm of chromosome 18.
We describe two patients with 18p monosomy who demonstrate that
hemizygosity of the genes located on the short arm of chromosome 18
cannot predict similar phenotype. Rather, multiple genetic and environmental
factors contribute most probably, to the spectrum phenotype.
Patient 1 is a 16 year old girl from Ethiopian origin who was born at
term to non-consanguineous healthy parents. She presented to our
clinic because of severe mental retardation, poor speech and communication
abilities. She has short stature and short webbed neck. No
other remarkable dysmorphic features were noticed.
Patient 2, is a four years old girl born prematurely at 26 weeks gestation,
to healthy unrelated parents. She presented with short stature,
mild mental retardation, speech delay and remarkable nasal-voice.
Karyotype analysis in both cases revealed deletion of the short arm of
chromosome 18, with patient 2 having complete deletion while patient
1 has near complete deletion.
These two patients demonstrate the complexity of the factors which
determine the final phenotype of monosomy 18p. Genetic counseling
should take into consideration the variable expression of this deletion
syndrome and the importance of comprehensive medical and educational
assessment, before a definite prognosis is determined.
P03.131
Pachygyria andpolymicrogyria, cranio-facial dysmorphism
and atrio-ventricular canal resulting from a duplication of the
proximal region of chromosome (p . )
B. Benzacken, L. Elkhattabi, l. Kraoua, A. C. Tabet, E. Pipiras, A. Delahaye, M.
Maurin, A. Verloes, A. Aboura;
Robert debré, Bd Sérurrier, France.
Clinical abnormalities included unusual cranio-facial features. He had
a microcephaly, a plagiocephaly and a small forehead, facial asymmetry
with a dysplastic right ear, upslanted palpebral fissures, ptosis
of the right eyelid, strabismus, long philtrum, congenital hypoplasia of
the left depressor anguli oris muscle, big ears, micrognathia and a
high arched palate. Physical examination revealed a continuous cardiac
thrill. A large ductus arteriosus with an auricular septal defect were
detected at ultrasound examination.
Congestive cardiac failure led to surgical treatment at 3 months of age.
Microcephaly was detected at 8 months, and a facial asymmetry became
obvious at that time. Ophtalmological examination and audiogram
were normal.
His early development was severely delayed and recurrent seizures
developed during the first year of life. Cerebral MRI examination
showed bilateral opercular dysplasia predominant on the right side and
gyration abnormalities with pachygyria and polymicrogyria.
Cytogenetic investigation from blood and skin samples demonstrated
a chromosomal mosaicism, with a dicentric chromosome 11 seen with
both G- and R-banding (25/25 abnormal cells on blood, 8/10 on skin)
(Fig.3a). C-banding demonstrated the presence of 2 centromeres, with
a small interposed euchromatic extra-material. Parental karyotypes