Lamins – proteins with intermediate filaments – are components of the internal membrane and internal structures of cell nucleus. Some lamins are encoded by the LMNA gene, located at the long arm of the chromosome 1 – 1q21-23. Mutations of this gene are responsible for several diseases in humans. Some of these diseases have been described long ago – they were considered very rare, they were not diagnosed properly, or their pathogenesis was unclear. Other diseases of this class only recently have appeared in medical handbooks. The key event in our understanding of laminopathies was elucidation in 1994 of the Emery-Dreifuss syndrome, well known to clinicians but rarely described hitherto. It is characterized by the triad of symptoms: early articular contractures (mainly of the cubital, talocrural and cervical vertebral joints), moderate atrophy and weakness of the brachial and peroneal muscle groups, and cardiomyopathy with conduction block, developing at the age of 20. The latter is the main life-threatening factor in Emery-Dreifuss syndrome patients. It became clear that the development of this condition depends on mutation of the STA gene, located at the long arm of the X chromosome (Xq28). The product of this gene is a protein included in the internal nuclear membrane, of molecular weight 34 kDa, called “emerin” in memory of Alan Emery. Its discovery marked a breakthrough in myology (hitherto it was believed that cell nucleus does not play any significant role in human pathology), paving the way for subsequent important discoveries. Among other things, it turned out that the Emery-Dreifuss dystrophy phenotype is not always associated with mutation of the STA gene or with emerin deficit. Growing interest in emerinopathy contributed to gathering of a fairly large number of patients featuring a similar phenotype but entirely different genotypic profile. The most important observation was that some patients phenotypically consistent with the Emery-Dreifuss syndrome, are afflicted with one of the many possible mutations of the LMNA gene. The disease has an autosomal dominant inheritance pattern (rarely autosomal recessive). The product of the LMNA gene are lamins A/C. The gene has 12 exons and depending on location of the mutation, several entirely different syndromes may develop. Thereof, the most important are: 

1.Emery-Dreifuss syndrome, featuring the same triad as the Emery-Dreifuss syndrome associated with emerinopathy; 

2.limb-girdle muscular dystrophy type 1B, characterized by an autosomal dominant pattern of inheritance; 

3.isolated, i.e. idiopathic dilated cardiomyopathy, characterized by an autosomal dominant inheritance pattern; 

4.Charcot-Marie-Tooth disease type 2B with axonal conduction disorders, characterized by an autosomal dominant inheritance pattern; 

5.familial partial lipodystrophy (Dunnigan type), featuring an autosomal dominant inheritance pattern; 

6.mandibuloacral dysplasia (MAD) – a rare yet very severe disease, featuring autosomal recessive inheritance pattern; 

7.Hutchinson-Gilford progeria, characterized by premature senescence of children, featuring autosomal dominant inheritance. 

In the field of laminopathies, which constitute a relatively novel area of research in medicine, we are struck by prominent role of cell nucleus and various mutations at several exons of the LMNA gene, resulting in different nosologic entities. From the clinician’s perspective, laminopathies (or nucleopathies in general) constitute a heterogenous group of hereditary diseases which damage skeletal muscles, cardiac muscle, connective tissue, nerves and bones. An interesting problem is “tissue specificity” of particular laminopathies, in spite of their presence in every tissue.