2008 Barcelona - European Society of Human Genetics

Cytogenetics
phic at delivery . Minor neonatal problems included polycythaemia and
neonatal jaundice. During the first months the baby was hypotonic.
Physiotherapy achieved walking at 16 months . Course was marked by
delayed speech with phonatory difficulties. Academic delay was due
mainly to hyperactivity and impaired concentration . At 9 years intelligence
was borderline (IQ:74) . Dysmorphic traits included small dysplastic
ears and a large mouth . There was strikingly happy and jovial
behaviour . Karyotype analysis of RHG and GTG-banded blood metaphases
showed 46 chromosomes, with an abnormally elongated long
arm of one chromosome 20 . Initial FISH studies (wcp 20, subtelomeric
20p and 20q probes and CEP 20 probe) suggested interstitial chromosome
20 duplication . Thorough FISH characterization of the anomaly
concluded to partial trisomy 20q11 .2 resulting from an inverted duplicated
chromosome 20 . A similar but apparently slightly larger duplication
was reported by Wanderley et al . in 2005 in a 16-month-old boy
with slightly dysmorphic features and the same happy disposition . This
behavioural characteristic could be related to 20q11 .2 duplication .
P02.142
De novo duplication of 7(q21.2----q32) in a patient: cytogenetic
diagnosis and clinical finding
F. Nasiri 1 , F. Mahjoubi 2 ;
1 Blood Transfusion Organization Research Center, Tehran, Iran, Tehran, Islamic
Republic of Iran, 2 Blood Transfusion Organization Research Center, Tehran,
Iran & National Institute for Genetic Engineering and Biotechnology, Tehran,
Iran, Tehran, Islamic Republic of Iran.
Trisomy/duplication of 7q is associated with a characteristic syndrome
and has been described in published cases . The main clinical features
are: frontal bossing , retrognathia, small jaw, low-set ears, dysplastic
ears, deep-set eyes, prominent eyes , strabismus, downcurved upper
lip, small mouth, short hands , stiffness fingers, joint laxity, joint
stiffness, scoliosis, reduced muscle tone, hydrocephalus, growth retardation,
strabismus, coloboma of iris, drooping upper eyelid, widely
spaced eyes, long eyelashes, short space between eyelids (1-8) .
Here we describe clinical and cytogenetic findings on a 1 year old male
child whom referred to our clinic due to developmental delay and hypotonia
.
To our best knowledge this report is the first case of a de novo case
with pure partial duplication of 7 (q21 .2----q32) .
P02.143
Rare unbalanced aberration of chromosome 18 in patient with
severe dysmorphic features and poor prognosis
A. Matulevičienė 1,2 , B. Aleksiūnienė 1,2 , N. Krasovskaja 1 , E. Preikšaitienė 2 , V.
Kučinskas 1,2 ;
1 Centre for Medical Genetics at Vilnius University Hospital Santariškių Klinikos,
Vilnius, Lithuania, 2 Department of Human and Medical Genetics Faculty of
Medicine, Vilnius University, Vilnius, Lithuania.
The unbalanced aberration of chromosome 18 is very rare chromosomal
rearrangements . We present a patient with rare unbalanced aberration
of chromosome 18. He was a first child of the first pregnancy from nonconsanguineous
parents . His mother was consulted during pregnancy
at the Center for Medical Genetics . Risk of congenital malformations
for foetus was calculated due to maternal age, gestation and obstetric
history . The risk of trisomy 21 was 1:1099 according to the mother’s
age . Ultrasound scan was performed at 16 th week of gestation . Neither
foetal structural malformations nor minor defects or markers of chromosomal
diseases were detected . Triple test was performed at 16 th week
of gestation . Biochemical risk of trisomy 21 was 1:55, for Trisomy 18
- 1:1708, for neural tube defects - 1:356 . According to biochemical test
results of trisomy 21 invasive procedure was performed for aneuploidy
testing by QF-PCR . Test results were negative . At birth the weight was
2470g and dysmorphic features were characterized - microcephaly,
low hairline, hypertelorism, prominent nasal bridge, long philtrum, short
neck, overlapping position of the fingers, micropenis and corpus callosum
agenesis. Expressed respiratory insufficiency was also observed.
The death at sixth months was final outcome of this patient. Chromosomal
analysis of peripheral blood lymphocytes revealed 46,XY,der(18)
t(4;18)(p14;q12 .2) karyotype . Cytogenetic analysis was performed from
GTG banded metaphases . The resolution level was 400-500 bands . Cytogenetic
investigation of the parents showed a chromosome aberration
in mother: she presented a t(4;18) (p14;q12.2). These results identified
the exact nature of the unbalanced aberration of our patient .
P02.144
A syndrome of ectodermal dysplasia and mR due
to del(2)(q31.2q33.2): further clinical and cGH-array
characterization
A. Verloes 1 , M. Port-Lis 2 , S. Drunat 3 , A. Tabet 3 , B. Benzacken 3 , L. Rifai 4 , A.
Aboura 3 ;
1 Robert debré, Paris, France, 2 Genetic Unit, University Hospital, Pointe-à-Pitre,
Guadeloupe, 3 Robert debré, Bd Sérurrier, France, 4 National Institute of Health,
Rabat, Morocco.
We report a patient with a 23 Mb deletion at 2q23, presenting with
severe growth and mental delay, and partial ectodermal dysplasia
(hair and teeth involvement) . This recurrent deletion appears to show
a consistent phenotype, previously reported in 4 cases . Further patients
will be necessary to determine which gene in the interval explain
skin and developmental anomalies . Comparing clinical features from
our patient and others who show an overlapping deletion, a common
“del 2q32 phenotype” emerge: microcephaly, long face, high forehead,
abnormal teeth, low-set ears, midface hypoplasia, high palate, micrognathia,
transparent and thin skin, sparse hair, high frequency of inguinal
hernia, severe development impairment, and behavioral problems.
Anomalies of hands and feet are also common: this might be caused
by the deletion of the HOXD cluster which is involved in distal limb
morphogenesis . Cleft palate is due to the deletion of the SATB2 gene
most likely by haploinsufficiency. Both ZNF533 and MYO1B genes are
located in the deleted region . They are involved in neuronal function .
These genes may be good candidates for the neurological phenotype
which is however not present to date in our patient . Is there a
new locus for ectodermal dysplasia on chromosome 2q31q33? This
hypothesis is supported by the observations of Stenvik et al . (1972)
who described patients with congenitally missing teeth and sparse
hair and taurodontia. Nails and ability to perspire were not specifically
mentioned . Levin (1985) saw brother and sister with hypodontia and
sparse, slow-growing hair . The sister had taurodontia of deciduous and
permanent teeth In addition, fingernails and toenails were slow-growing,
thin, and spoon-shaped . No abnormalities in perspiration were
noted . (taurodontia, absent teeth, and sparse hair . MIM 272980)
P02.145
A 6qter deletion results in a phenotype of mental retardation and
classical cutaneo-articular Elhers-Danlos syndrome
A. Mosca 1 , P. Callier 1 , A. Masurel-Paulet 2 , C. Thauvin-Robinet 2 , N. Marle 1 , M.
Nouchy 3 , D. Dipanda 4 , F. Mugneret 1 , L. Faivre 2 ;
1 Laboratoire de cytogénétique, CHU le Bocage, Dijon, France, 2 Service de
Génétique Médicale, Hôpital d’Enfants, Dijon, France, 3 Laboratoire Pasteur
Cerba, Val-d’Oise, France, 4 Service de Rééducation et de Réadaptation, CHU
le Bocage, Dijon, France.
Ehlers-Danlos syndromes (EDS), belonging to a heterogeneous group
of inheritable connective tissue disorders, are attributed to mutations
within a subunit of the V th chain of the collagen gene . Here, we report
on a 6-year-old patient with history of congenital hip dislocation, major
joint hypermobility, fragile and hyperextensible skin, persistent atrophic
scars, and asthenia . Her father and one of her sisters had mild
joint laxity . She was referred to the genetics department for investigations
of speech delay, mild mental and growth retardation and minor
dysmorphic features . A standard karyotype revealed a 6qter deletion .
Cytogenetic studies of the parents were normal in favour of a de novo
deletion. A CGH-array (Integragen) is in progress to better characterize
the breakpoints of this deletion . Cerebral magnetic resonance imaging,
cardiac and abdominal ultrasounds were normal . It is interesting
to note that two patients with EDS type VII and EDS type II respectively
have been reported with a 6q deletion . None of the genes of this subtelomeric
6qter region seems to be a strong candidate gene by its
function for EDS . The review of other cases with chromosome 6q deletions
including the q26-q27 bands did not show any other cases with
EDS phenotype but revealed patients with congenital hip dysplasia .
P02.146
Encountered chromosomal abnormalities in children with
epilepst
E. R. Raouf, N. A. Mohamed;
National Research Center, Cairo - Giza, Egypt.
Objective: Increased evidences of chromosomal aberrations in association
with epilepsy suggest a genetic predisposition to the disease . We