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

Molecular and biochemical basis of disease
didate for CGH array.
During this initial phase of application of the diagnostic protocol, we
have identified a mutation in the TBX5 gene in a patient who was previously
considered to be affected with isolated ToF. The mutation leads
to aminoacid substitution of arginine into a stop codon (R279X). Careful
physical examination of the patient showed subtle hand malformation
in form of long first metacarpal, that can coincide with Holt Oram
syndrome diagnosis. To the best of our knowledge this mutation has
never been associated with ToF phenotype.
P0756. Purple and Yellow. Hereditary Coproporphyria and
Gilbert’s Syndrome in Czech Family.
J. Prochazkova, L. Barnincova, M. Tomkova, J. Zeman, P. Martasek;
Department of Pediatrics, 1st School of Medicine, Charles University, Prague,
Czech Republic.
Hereditary coproporphyria is a rare acute hepatic porphyria with autosomal
dominant inheritance characterized by deficient activity of coproporphyrinogen
III oxidase (CPO). The gene encoding human CPO
has been cloned and localized to chromosome 3q11.2. The CPO gene
spans 14 kb and has a single promoter and seven exons. The cDNA
encodes a protein containing 354 amino acids. The enzyme is active
as a homodimer of 76 kDa.
Gilbert´s syndrome (GS) is a hereditary, autosomal recessive disorder
with mild, unconjugated hyperbilirubinemia. In Caucasian patients, Gilbert’s
syndrome is linked primarily with a TA insertion in the TATA box
promoter of the UGT1A1 gene, most frequently present as A(TA)7TAA
rather than A(TA)6TAA.
In this study, we report on patient with hereditary coproporphyria associated
with Gilbert´s syndrome. Molecular diagnosis of the regulation
region of the UGT1A1 gene showed a TA insertion in the promoter.
Analysis of the CPO gene revealed a small deletion of 3 bp at nucleotide
1168 (390delGly) in exon 5. This deletion removes glycine without
altering the coding frame. Mutational analyses were carried out on sixteen
members of proband’s family.
Supported by MSMT 1M6837805002, MSMT 0021620806, GACR
303/03/H065
P0757. Analysis of connexin 32 gene (GJB1, Cx32) in the
hereditary motor and sensory neuropathy (HMSN) patients from
Bashkortostan
E. G. Latypova1 , I. M. Hidiyatova1 , N. B. Krupina2 , R. V. Magjanov2 , E. K. Khusnutdinova1
;
1 2 Institute of Biochemistry and Genetics, Ufa, Russian Federation, Bashkir
State Medical University, Ufa, Russian Federation.
Hereditary motor and sensory neuropathy (HMSN) or Charcot-Marie-Tooth
(CMT) disease is a clinically and genetically heterogeneous
disorder of peripheral nervous system. The HMSN frequency in Bashkortostan
Republic (BR , Russia, the territory of the South Urals) is
10,3:100000. HMSN type I is prevalent in BR. In 104 unrelated HMSN
families gene PMP22 duplication screening was carried previously and
obtained that this mutation frequency in BR is 20,63% for all types of
HMSN and 45,0% - for HMSN type I.
In this investigation the searching of mutations in GJB1 gene in patients
without PMP duplication (114 affected members from 77 unrelated
families) was carried.Two mutations and one polymorphism
- Pro87Ala, Arg22Gln and 45G>A we determined using SSCP analysis
followed by sequencing of shifted samples. It turned out, that Pro87Ala
mutation is frequent among HMSN patients from Bashkortostan, it was
revealed in 13 unrelated families, that amount 12,03% for all types of
HMSN and 20,63% - for HMSN type I. This mutation was the most frequent
in patients of Bashkir ethnic origin (35% in Basckir patients), less
frequent - in Russian (10,8%) and Tatars (3,20%). Arg22Gln mutation
was defined in three patients from two families of Tatar ethnic origin
(2,77% for all patients from BR and 6,45% for Tatar patients without
HMSN type differentiation. Both found mutations were described previously,
they cause the dominant form of HMSN type I with relatively mild
clinical features. The polymorphism 45G>A revealed in two unrelated
patients of Mordvinian ethnic origin, it was not describe earlier.
202
P0758. High throughput Genotyping: New Diagnostic
Resequencing Microarray for Hereditary Spastic Paraplegia
C. Dufke 1 , R. Schüle 2 , A. Seibel 2 , M. Bonin 3 , S. Poths 3 , P. Bauer 1 , L. Schöls 2 ;
1 Institute of Human Genetics, Tübingen, Germany, 2 Hertie-Institute für Klinische
Hirnforschung, Tübingen, Germany, 3 The Microarray Facility, Tübingen, Germany.
Hereditary Spastic Paraplegia (HSP) is a heterogenous group of inherited
neurological disorders. Insidiously progressive spastic weakness
of the lower extremities is the common criteria in all 33 forms described
so far. Autosomal dominant, autosomal recessive and X-linked mode
of inheritance have been described. Clinically HSP is differentiated into
pure (uncomplicated) and complex (complicated) forms, depending on
isolated impairment of corticospinal tracts or more wide spread affection
of neuronal circuits or systemic involvement.
For proper diagnosis moleculargenetic analysis is fundamental since
clinical parameters alone are not reliable in distinguishing HSP forms.
In order to establish high throughput genotyping, we designed a HSP
resequencing microarray (Affymetrix platform) covering the coding exons
and flanking intronic sequences of the HSP genes L1CAM (SPG1),
PLP1 (SPG2), Atlastin (SPG3A),Spastin (SPG4), NIPA1 (SPG6), Paraplegin
(SPG7), KIF5A (SPG10), HSP60 (SPG13), BSCL2 (SPG17),
Spartin (SPG20), Maspardin (SPG21),
(13 - 94kb, 5 - 28 coding exons), as well as the 59 most frequent small
deletions, insertions and insertion/deletions in these genes.
We present data on microarray analysis of 20 autosomal dominant
HSP index patients.
P0759. Elucidating the molecular function of Zfyve27, the gene
mutated in hereditary spastic paraplegia (SPG33)
A. U. Mannan, K. Pantakani, W. Engel;
Institute of Human Genetics, Goettingen, Germany.
Hereditary spastic paraplegias (HSP) are a group of neurodegenerative
disorders, which are clinically characterized by progressive spastic
paralysis of the legs, usually caused by a length-dependent distal degeneration
of the corticospinal tract axons. HSP are genetically heterogeneous
and till now 35 loci have been identified. Recently, we reported
a mutation in a novel endosomal protein ZFYVE27 (SPG33) in a
German family with autosomal dominant HSP. ZFYVE27 was identified
as a spastin interacting protein and we have characterized the interaction
between these two proteins in mammalian cells. Moreover, our
studies revealed that the mutated ZFYVE27 protein shows aberrant
intracellular pattern in tubular structure of cells and its interaction with
spastin is severely affected. Intracellular distribution studies revealed
that ZFYVE27 is expressed in punctate vesicles which were both of
endosomal and endoplasmic reticulum origin. Furthermore, overexpression
of GFP-ZFYVE27 in fibroblast (NIH3T3) cell line, promoted
neurite formation through directional membrane trafficking process. A
comprehensive expression analysis of Zfyve27 through Western blot
revealed high level of Zfyve27 primarily in the HSP affected tissues in
mouse such as brain, cerebellum and spinal cord. To gain mechanistic
insights in murine Zfyve27 function, currently, generation of loss of
function mouse models by using both gene-trap and knockout strategy
are in progress.Conceivably the phenotype of these mouse models
might mimic the pathological features of HSP, therefore will provide
us with a valuable model system to elucidate the underlying cause for
HSP etiology.
P0760. MLH1 promoter methylation in peripheral blood cells of
12 patients clinically presenting HNPCC features
M. Grabowski 1 , H. K. Schackert 2 , N. Rahner 3 , M. Ebert 4 , C. Walldorf 3 , B. Royer-Pokora
5 , B. Betz 5 , W. Schmiegel 6 , M. von Knebel-Doeberitz 7 , W. Dietmaier 8 ,
G. Keller 9 , B. Kerker 1 , G. Leitner 10 , E. Holinski-Feder 11 ;
1 Ludwig-Maximilians-University Munich, Munich, Germany, 2 Department of
Chirurgic Research, University of Dresden, Dresden, Germany, 3 Institute of
Human Genetics, University of Bonn, Bonn, Germany, 4 Hospital for Gastroenterology
and Hepatology, Otto-von-Guericke-University, Magdeburg, Germany,
5 Institute of Human Genetics, University of Düsseldorf, Düsseldorf, Germany,
6 Hospital of the University of Bochum, Bochum, Germany, 7 Institute of Pathology,
University of Heidelberg, Heidelberg, Germany, 8 Institute of Pathology,
University of Regensburg, Regensburg, Germany, 9 Institute of Pathology, University
of Technology, Munich, Germany, 10 Center of Medical Genetics, Munich,
Germany, 11 Institute of Human Genetics, Ludwig-Maximilians-University/Center