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Genetics of laminopathies
Rabah Ben Yaou1, Antoine Muchir, Takuro Arimura
1Inserm U582, Institut de Myologie, Batiment Babinski, Groupe Hospitalier Pitié-Salpe'triire, 47, Boulevard de l'Hôpital, Paris, France.
Novartis Foundation Symposium
|March 19, 2005
Summary
Laminopathies, caused by LMNA gene mutations, lead to diverse disorders affecting muscles, nerves, and aging. Research is exploring genotype-phenotype links and using mouse models to understand disease mechanisms.
Area of Science:
- Genetics
- Molecular Biology
- Cell Biology
Background:
- Laminopathies are disorders arising from mutations in the LMNA gene, encoding A-type lamins.
- LMNA mutations are linked to Emery-Dreifuss muscular dystrophy, dilated cardiomyopathy, and other conditions affecting muscle, adipose, nervous, and bone tissues, as well as premature aging.
- Over 180 distinct LMNA mutations have been identified in numerous individuals.
Purpose of the Study:
- To investigate the relationship between LMNA mutation types/locations and associated phenotypes.
- To study the cellular consequences of LMNA mutations in patient-derived fibroblasts.
- To utilize genetically modified mouse models for understanding laminopathy pathophysiology.
Main Methods:
- Analysis of genotype-phenotype correlations in patients with LMNA mutations.
- Examination of nuclear morphology and protein expression (B-type lamins, emerin) in cultured skin fibroblasts.
- Development and study of knockout (KO) and knock-in (KI) LMNA mouse models.
Main Results:
- Initial studies found limited clear genotype-phenotype correlations, with potential exceptions in the globular tail domain of lamins A/C.
- Cultured fibroblasts from patients exhibit abnormal nuclear shapes and altered expression of B-type lamins and emerin.
- LMNA mouse models, such as Lmna(H222P/H222P), display phenotypes resembling Emery-Dreifuss muscular dystrophy.
Conclusions:
- LMNA mutations cause a spectrum of diseases with complex genotype-phenotype relationships.
- Cellular abnormalities in fibroblasts provide insights into disease mechanisms.
- LMNA mouse models are valuable tools for elucidating the pathophysiology of laminopathies.