30.10.2013 Views

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

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

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

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Clinical genetics<br />

Posters<br />

Po01. Clinical genetics<br />

P0001. A 17q21.31 microduplication (including MAPT) and a<br />

2q22.3q23.1 microdeletion (including ACVR2A) detected by<br />

routine array-CGH analysis using 244k Agilent oligoarrays in two<br />

patients with mental retardation and dysmorphic features<br />

M. Kirchhoff1 , A. M. Bisgaard1 , M. Duno1 , F. J. Hansen2 , H. Rose1 , M.<br />

Schwartz1 ;<br />

1 2 Department of Clinical <strong>Genetics</strong>, Rigshospital, Copenhagen, Denmark, Department<br />

of Pediatric Neurology, Rigshospital, Copenhagen, Denmark.<br />

Two cases with de novo chromosomal imbalances detected by routine<br />

screening using 244k Agilent oligoarrays are presented. In case<br />

1, a microduplication of 17q21.31 was found (approximately 0.5 Mb).<br />

The duplication is reciprocal to the recently described 17q21.31 microdeletion<br />

and includes the MAPT gene. The patient is a nine-year-old<br />

girl with severe psychomotor developmental delay. Her facial dysmorphism<br />

includes a low anterior and posterior hairline, a small nose with<br />

a flat root, a long philtrum, and small widely spaced teeth. In addition,<br />

she has microcephaly, abnormal fingers and toes, and hirsutism with<br />

very long hairs on her back. In case 2, a microdeletion of 2q22.3q23.1<br />

was found (approximately 0.4 Mb). The deletion includes the ACVR2A<br />

gene, which has been associated with cranio-facial development in<br />

mice. The patient is a three-year-old girl. Her psychomotor development<br />

is approximately 12 months delayed. Her facial dysmorphism<br />

includes lateral extension of eyebrows, a low anterior hairline, long<br />

palpebral fissures, a high nasal bridge giving the impression of deepset<br />

eyes, a bulbous nasal tip, a thin upper lip, and micrognathia/retrognathia.<br />

In addition, she is microcephalic, hypermobile and hypotonic.<br />

Beside the two patients an outline will be presented from seven months<br />

of routine CGH-analysis using 244k Agilent oligoarrays of patients with<br />

mental retardation and dysmorphic features.<br />

P0002. Clinical and cytogenetic aspects in two children with<br />

trisomy 18<br />

M. Budisteanu 1 , A. Arghir 1 , I. Minciu 2 , S. Magureanu 2 , G. Chelu 1 , A. Lungeanu 1 ;<br />

1 ”Victor Babes” National Institute of Research and Development, Bucharest,<br />

Romania, 2 Clinical Hospital of Psychiatry “Prof. Dr. Al. Obregia”, Bucharest,<br />

Romania.<br />

Objective: The authors present two cases of trisomy 18 with different<br />

clinical and cytogenetic characteristics.<br />

Material and methods: The children were admitted to the Department<br />

of Pediatric Neurology of the Clinical Hospital Al. Obregia, Bucharest<br />

for evaluation of a delayed psychomotor development. They were included<br />

in a large study, part of a national research program, which<br />

investigate the cytogenetic causes of MR in children. First case, an<br />

eight years old girl, showed: dysmorphic features, severe MR, hyperkinesia<br />

with self-injurious behavior. Second case, a four months old<br />

girl, displayed the clinical phenotype characteristic of Edwards syndrome<br />

(including dysmorphic features, failure to thrive, arthrogryposis,<br />

epileptic seizures, brain malformation). The children were investigated<br />

cytogenetically by karyotype with GTG-banding.<br />

Results: In the first case, the cytogenetic investigation revealed a partial<br />

trisomy 18pter-18q21. In the second case, the diploid karyotype<br />

showed a duplication of the long arm of chromosome 18.<br />

Conclusions: The phenotype of the patients with trisomy 18 can be different<br />

depending on the specific triplicated chromosomal region. For<br />

a better description of the sequences involved in the breakpoints in<br />

this two cases, we intend to extend the study by applying molecular<br />

genetic methods.<br />

P0003. CYP21A2 genotyping in an Italian population with 21hydroxylase<br />

deficiency: molecular characterization of 1050<br />

alleles<br />

L. Baldazzi1 , S. Menabò1 , A. Balsamo1 , M. Barbaro1,2 , A. Nicoletti1 , G. Cangemi1<br />

, A. Cicognani1 ;<br />

1Pediatric Department S.Orsola-Malpighi University Hospital, Bologna, Italy,<br />

2Center for Molecular Medicine Karolinska University Hospital, Stockolm, Sweden.<br />

Steroid 21-hydroxylase deficiency (21OHD), an autosomal recessive<br />

disorder caused by mutations in the CYP21A2 gene and responsible for<br />

>90% of cases of congenital adrenal hyperplasia, presents a wide phe-<br />

notypic spectrum ranging from a severe classical form (CL, 1/15000)<br />

with or without salt wasting, through to a mild nonclassical form (NC,<br />

1/100), to a hyperandrogenic adult form. The active gene and the inactive<br />

pseudogene CYP21P are organized in a complex locus on chromosome<br />

6p21.3. Most of the genetic lesions that cause 21OHD are<br />

deletions/conversions (often giving rise to chimeric CYP21P/CYP21<br />

genes) or various gene conversion-type mutations resulting in CYP21<br />

genes carrying one/multiple pseudogenic mutations. Mutations arising<br />

independently of the pseudogene are rare.<br />

A molecular strategy analysis that combines specific PCR (designated<br />

to avoid allele dropout phenomena caused by pseudogene sequences<br />

and to discover a chimeric gene), sequencing of the entire CYP21A2<br />

gene region (from nt-420 to nt+2907), as well as intragenic polymorphism<br />

segregation analysis, enabled us to characterize a total of 1050<br />

alleles of: 383 21OHD patients (<strong>16</strong>2 CL, 231 NC) and 136 hyperandrogenic<br />

subjects with 98.8% of mutation detection. Mutations were<br />

confirmed in the parents in 85% of the cases. Single/multiple pseudogene-derived<br />

mutations account for 93.2% of the alleles, whereas<br />

5.6% carry a rare/new mutation, mostly missense mutations affecting<br />

a conserved residue. Functional studies of 3 new mutations confirmed<br />

their implication in the phenotype observed. The genotype/phenotype<br />

relationship was generally good. Further studies will focus on rare variants<br />

in the non coding regions associated with mild forms.<br />

P0004. A boy with 3q29 microdeletion and congenital mitral<br />

valve stenosis<br />

A. Stray-Pedersen1 , K. L. Eiklid2 , K. Ramstad1 , O. K. Rødningen2 ;<br />

1 2 Rikshospitalet-Radiumhospitalet, Oslo, Norway, Ulleval University Hospital,<br />

Oslo, Norway.<br />

We present an 8 year old boy with congenital mitral valve stenosis<br />

and mental retardation. Clinical findings: progressive microcephaly,<br />

epicanthus, antimongoloid eye shape, oedematous eyelids, prominent<br />

nasal tip, irregularly and widely spaced teeth. He has hypotonic musculature<br />

with pronounced joint laxity both elbows. He has overriding 2nd toes, fetal pads toes and fingers. He is developmentally retarded. He<br />

started to walk at 23 months of age. His language is severely delayed,<br />

and he has autistic-like features.<br />

Array CGH using CytoChip (BlueGnome Ltd.) revealed an interstitial<br />

microdeletion of chromosome 3q29. This microdeletion is reported<br />

in only 7 patients worldwide. The clinical phenotype in the reported<br />

cases is variable despite an almost identical deletion size. It includes<br />

mild/moderate mental retardation and progressive microcephaly with<br />

mildly dysmorphic facial features (long and narrow face, short philtrum<br />

and high nasal bridge).<br />

The phenotype in our patient is very similar to the other cases, but<br />

mitral valve stenosis is not reported in the 7 other patients. However,<br />

early death (at 3mo-5y) caused by cardiac events has been reported<br />

in some of the other patients with 3q29 microdeletion, and terminal<br />

deletions of chromosome 3q are associated with congenital heart defect.<br />

The microdeletion encompasses several genes including PAK2.<br />

This gene is the autosomal homologue of a known X-linked mental<br />

retardation gene (PAK3), and might be the cause of mental retardation<br />

in the patients. The specific gene causing the heart defect reported in<br />

our patient is unknown. Our patient’s phenotype broadens the clinical<br />

spectrum of the 3q29 microdeletion syndrome.<br />

P0005. Subtelomeric 6p deletion: clinical and array-CGH findings<br />

in two patients<br />

I. Filges1 , D. Martinet2 , F. Bena1 , N. Besuchet2 , I. Bouchardy1 , A. C. Gaide2 , S.<br />

E. Antonarakis1 , J. Beckmann2 , M. A. Morris1 , A. Bottani1 , M. C. Addor2 ;<br />

1Medical <strong>Genetics</strong> Service, Geneva University Hospitals, Geneva, Switzerland,<br />

2Medical <strong>Genetics</strong> Service, Centre Hospitalier Universitaire Vaudois, Lausanne,<br />

Switzerland.<br />

Approximately 30 patients with subtelomeric 6p deletion have been<br />

reported. A recognizable phenotype, including hypertelorism, downslanting<br />

palpebral fissures, flat nasal bridge and dysplastic ears, has<br />

been delineated. In addition to variable mental retardation and potential<br />

hearing deficit, there is a distinctive malformation pattern, which<br />

comprises anterior eye chamber malformations, posterior fossa/cerebellar<br />

anomalies, and heart defects.<br />

Patient 1 is an 8-month-old female born with normal growth parameters,<br />

typical facial features of 6pter deletion, bilateral corectopia, and<br />

protruding tongue. She has severe developmental delay, profound bi-

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!