Disorders of Lamins in Affections of the Heart and Skeletal Muscles
Špinarová L.1, †Toman J.1, Hude P.1, Voháňka S.2, Vytopil M.2, Lukáš Z.3, J.1, Hude P.1, Voháňka S.2, Vytopil M.2, Lukáš Z.3,
1I. interní kardio-angiologická klinika Lékařské fakulty MU a FN u sv. Anny, Brno, přednosta prof. MUDr. Jiří Vítovec, CSc.2Neurologická klinika Lékařské fakulty MU a FN Brno, pracoviště Bohunice,přednosta prof. MUDr. Zdeněk Kadaňka, CSc.3Patologicko-anatomický ústav Lékařské fakulty MU a FN Brno, pracoviště Bohunice,přednosta prof. MUDr. Karel Dvořák, DrSc. |
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Summary:
The Emery-Dreifuss muscular dystrophy is caused by muscular lesions and disorders of cardial
rhythm and/or by cardiomyopathy. An autosomal dominant form is related to mutations of genes,
which are coding for lamins A/C. Group and Methods: In the group A the authors examined 37
patients with the diagnosis of dilatation cardiomyopathy (DKMP) and the mean ejection fraction
28.4 ; 8.8%. In the group B of 13 patients a cardiac stimulator was implanted for a rhythm disorder.
Both groups were subjected to cardiological, neurological, clinical and electromyographic (EMG)
examinations. A muscle biopsy from m. vastus lateralis was made and the sample was evaluated
by histology, histochemistry and immunohistochemistry. The coding sequences of genes for lamins
were amplified by polymerase chain reaction and the products were analyzed by the DHPLC
method (denaturing higher performance liquid chromatography). Results: In the group A there
was a clinically myopathic picture in three patients, while EMG examination revealed a myogenic
finding in 12 patients and a marginally myogenic one in five patients. The histological finding in
12 patients was evaluated as myogenic and marginally myogenic in six. In one patient the mutation
analysis revealed mutation in the gene for lamin A/C. A myogenic finding in this patient was
determined by EMG as well as by histological examination and the autosomal dominant form of
the Emery-Dreifuss muscular dystrophy was therefore diagnosed. In the group B one patient
displayed a myopathic neurological finding and a myogenic finding during EMG. A subsequent
mutation analysis revealed a mutation in the gene for lamin A/C. The case was therefore the
autosomal dominant form of the Emery-Dreifuss muscular dystrophy. In the other patients the
clinically marginal myopathic finding was observed once, a marginally myogenic finding during
EMG was seen five times, histology and immunochemistry revealed a myogenic finding once and
a marginally myogenic finding also once. The other findings were within normal range. Conclusions:
a careful neurological examination including EMG determined symptoms of skeletal muscle
myopathies in a surprisingly high percentage of our cardiological patients. This observation
draws attention to the need of neurological examination in patients with DKMP in order to discoved disorder in this area in time. In two patients mutations in genes coding lamins A/C were
detected. It would be useful to analyze also genes coding for other cytoskeletal proteins in the
future.
Key words:
Dilatation cardiomyopathy – Muscular dystrophy – Mutation of genes for lamins
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