ABSTRACT
Mutations in LMNA gene produce a wide spectrum of disorders called laminopathies. In this article, the first cases of laminopathies from Russia are reported. In 10 unrelated families, 9 different mutations were identified: Asp47His, Gly232Arg, c.[781_783delAAG, 781insGTGGAGCAGTATAAGAAA], Arg249Gln (in two families), Arg377His, Arg541His, Ala350Pro, Leu52Pro, and Gly635Asp. Mutations Arg249Gln, Arg377His, and Arg541His were reported previously, others are novel. Four cases present de novo mutations, among them two cases with Arg249Gln are found. Because this mutation occurred de novo also in other reported cases, a mutational 'hot spot' was supposed. Three phenotypes were observed: autosomal dominant (AD) Emery-Dreifuss muscular dystrophy (EDMD), limb-girdle MD type 1B, and AD dilated cardiomyopathy with conduction defect type 1A (DCM1A). Atypical clinical presentations were a very severe EDMD and an infantile DCM1A.
Subject(s)
Lamin Type A/genetics , Mutation , Cardiomyopathy, Dilated/genetics , DNA Mutational Analysis , Family Health , Genes, Dominant , Humans , Muscular Dystrophies, Limb-Girdle/genetics , Muscular Dystrophy, Emery-Dreifuss/genetics , Phenotype , Russia/epidemiologyABSTRACT
Familial benign polycythemia (FBP) (OMIM 263400) is a rare autosomal recessive condition characterized by erythrocytosis, normal leukocyte and platelet counts, normal uric acid level, and usually increased erythropoietin production. There is a high incidence of this disorder in Chuvashia (Russian Federation), probably due to a founder effect. In an attempt to locate the gene responsible for this disorder, we have carried out linkage studies in 12 Chuvash families, with 35 affected and 32 unaffected members. Linkage to the erythropoietin and erythropoietin receptor loci was excluded, and the FBP gene was assigned to the region of chromosome 11q23 between D11S4142 and D11S1356, with a maximal lod score of 6.61.
