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

Clinical genetics
nosed. Accurate revision of Xrays permitted to identify cervical lordosis,
C2-C3 fusion, lumbar scoliosis, thoracolumbar vertebral differentiation
defects with lumbar ribs and S1 lumbarization. Audiometry and
echocardiogram were normal.
Presently, she has short stature, obesity (BMI 30.7) and head circumference
at the 3 rd percentile. Long face, tubular nose with bulbous tip,
low-set and small ears, high palate, nasal speech and slender hands
are noted. The karyotype was normal. Unexpectedly, array-CGH analysis
(75 kb resolution) revealed a 22q11.2 deletion, of about 2,5 Mb in
size. MLPA analysis showed that the deletion was absent in her parents,
demonstrating that the deletion was de novo. In 2006, Cheroki et
al., reported another case of a 22q11 deletion in a patient with Mayer-
Rokitansky-Kuster-Hauser anomaly (Müllerian Duct aplasia), Hashimoto
thyroiditis and renal, cardiac and skeletal defects. We discuss
whether this is a casual association or one additional syndrome due to
the well known extensive phenotypic variability of the 22q11 deletion
syndrome.
P0198. Screening human genes for small alterations performing
an enzymatic cleavage mismatched analysis (ECMA) protocol
N. Vogiatzakis, K. Kekou, C. Sophocleous, S. Kitsiou, A. Mavrou, E. Kanavakis;
University of Athens,School of Medicine, Athens, Greece.
Many human diseases are caused by small alterations in the genes
and in the majority of cases sophisticated protocols are required for
their detection. In this study we estimated the efficacy of an enzymatic
protocol, which using a new mismatch-specific DNA plant endonuclease
from celery (CEL family) recognizes and cleaves mismatched alleles
between mutant and normal PCR products. The protocol was
standardized on a variety of known mutations, in 11 patients with cystic
fibrosis (CF), Fabry’s disease (FD), steroid 21-hydroxylase deficiency
(21-HD) and Duchenne/Becker muscular dystrophy (DMD/BMD). The
results showed that the method is rapid, effective, safe, reliable and
very simple, as the mutations are visualized on agarose or nusieve/
agarose gels where the location of the alteration is indicated by a size
marker. The method does not require special equipment, labeling or
standardization for every PCR product, since conditions of heteroduplex
formation and enzyme digestion are universal for all products.
The protocol was furthermore evaluated in three DMD patients with the
detection of three alterations, which after sequencing, were characterized
as disease causative mutations (all of them nonsense on exons
21 and 44). The proposed assay, which was applied for the first time
in a variety of monogenic disorders, indicates that point mutation identification
is feasible in any conventional molecular lab. Alternatively it
could be performed for cases where other techniques have failed.
P0199. LMX1B and Nail patella syndrome: experience in 16
families and genotype-phenotype correlation
S. N. Manouvrier 1 , F. Escande 2 , A. Dieux-Coeslier 1 , A. Mezel 3 , M. Holder-Espinasse
1 ;
1 Clinical genetic departement, university hospital, Lille, France, 2 Molecular Biology
laboratory, University Hospital, Lille, France, 3 Paediatric Surgery department,
University Hospital, Lille, France.
NPS is characterized by cardinal limb anomalies (nail dysplasia, absent
or hypoplastic patellae, iliac horns, abnormality of the elbows…),
in some cases nephropathy (glomerulonephritis) and/or eye involvement
(glaucoma, cataract). Hearing loss and scoliosis have also been
described. NPS is due to mutations in LMX1B, a gene located at
9q34.1. LMX1B codes for LIM-homeodomain transcription factor involved
in normal patterning of the dorsoventral axis of the limb and
early morphogenesis of the glomerular basement membrane
We sequenced LMX1B gene in 16 families (22 patients) with nail-patella
syndrome (NPS).
The diagnosis of nail patella syndrome was typical in 13 index patients,
due to characteristic limb anomalies. The tree remaining patients
were a boy with limb features of NPS and mental retardation,
but no 9q34.1deletion; a man with isolated nephropathy, and a woman
with atypical limb anomalies.
We found LMX1B “stop” or “frame shift” mutations in 8/13 (62%) typical
index patients and nonsense mutations in two atypical patients (the
boy with NPS and mental retardation, and the woman with atypical
NPS).
In all but one mutated families limb anomalies were isolated. In one
sporadic patient with p.Gln37X mutation nephropathy was present and
typical limb anomalies were associated with radio-ulnar synostosis.
The identified mutations were more frequent in exons 2, 4 and 5. No
clear genotype-phenotype correlation appeared in this small series.
The non-mutated cases were 3 typical familial NPS with renal involvement
in two instances, and one sporadic typical NPS case with proteinuria.
We are searching for LMX1B deletion in these cases.
P0200. A novel type of TPM mutation causing autosomal
recessive nemaline myopathy in two Turkish families
V. L. Lehtokari 1,2 , K. Pelin 3 , K. Donner 4 , T. Voit 5 , S. Rudnik-Schöneborn 6 , C.
Wallgren-Pettersson 1,2 ;
1 The Folkhälsan Institute of Genetics, Helsinki, Finland, 2 Department of Medial
Genetics, University of Helsinki, Helsinki, Finland, 3 Department of Biological
and Environmental Sciences, University of Helsinki, Helsinki, Finland, 4 Research
Program for Molecular Medicine, University of Helsinki, Helsinki, Finland,
5 Institut de Myologie, Paris, France, 6 Institute for Human Genetics, RWTH
Aachen University, Aachen, Germany.
Congenital myopathies include a wide spectrum of clinically, histologically
and genetically variable neuromuscular disorders defined by
structural abnormalities in the muscle fibres. Nemaline (rod) myopathy
(NM) is a rare congenital myopathy diagnosed on the basis of muscle
weakness and nemaline bodies in the muscle fibres. The nemaline
bodies are protein aggregates derived from sarcomeric Z discs and
thin filaments. The six known NM genes all encode proteins for the
thin filament of the muscle sarcomere: nebulin, alpha-actin1, beta- and
gamma-tropomyosins, troponin T1 and cofilin 2. In order to identify the
seventh NM gene we performed a genome-wide linkage study using
microsatellite markers in 12 Turkish families with recessive NM. The
hunt for the new gene is still ongoing, but in the context of this linkage
study we identified a novel mutational mechanism for nemaline
myopathy caused by alterations of the TPM3 gene.
Two consanguineous Turkish families with two children each affected
by a severe form of nemaline myopathy were found to have a homozygous
deletion of the first nucleotide, an adenine, of the last exon
of TPM3. The mutation in the last nucleotide before the STOP codon
disrupts the reading frame and causes read-through across the STOP
codon. The parents are healthy mutation carriers. RT-PCR predicts
this to result in a TPM3 protein elongated by 75 amino acids. This is
the first deletion to be identified in TPM3, and it may turn out to be
a founder mutation among Turkish NM families. Further studies are
ongoing.
P0201. Processing of Data Records on Patients with
Neurofibromatosis Type 1 Using the Artificial Intelligence
Methods
T. Marikova1 , S. Bendova1 , B. Petrak1 , L. Kinstova1 , M. Zakova2 , L. Novakova2 ,
O. Stepankova2 ;
1 2 2nd Medical School, Prague 5 - Motol, Czech Republic, Czech Technical
University, Prague, Czech Republic.
250 patients with NF1 were clinically examined in detail. The patients
were tested according to the NIH diagnostic criteria. The DNA bank
for these patients was created containing 110 DNA samples. We have
implemented direct DNA analysis of the NF1 gene using the MLPA
and DHPLC methods and found NF1 mutations in 17 patients: 15
causal mutations were detected exploring the DHPLC method. Using
the MPLA method, two large deletions have been identified.12 of the
above mentioned mutations were newly found.
The patient records are stored in the form of text files. Their content
has to be presented in a database format to analyze them by available
machine learning techniques. To support this transformation we have
implemented MedAT - a tool for annotation and analysis of text files.
Our program currently contains four knowledge ontologies - anamnesis,
clinic symptoms, genealogy and mutations, which shape computer
supported extraction of important information from patients’ records.
The set of ontologies can be easily modified. This approach enables
dynamic processing and efficient analysis of available patients’ data
and it significantly contributes to achieving the main goals of this research:
• specification of diagnostic criteria for NF1 for Czech population
• genotype/phenotype correlation for patients with different types of
mutations,
• determining the incidence and prevalence