The diversity of hereditary pathology in 5 regions of Kostroma district was 
studied. 32 nosological forms of autosomal dominant, 30 autosomal recessive and 
7 X-linked recessive disorders were found. The most frequent autosomal dominant 
disorders were: neurofibromatosis, pigmentary degeneration of retina, 
hypochondroplasia, ichtiosis, idiopathic scoliosis. The most frequent among the 
autosomal recessive disorders were: oligophrenia, pigmentary degeneration of 
retina, muscular atrophy of juvenile Kugelberg--Welander type, congenital 
cataract. The most frequent X-linked disorders were: muscular Duchenne type 
dystrophy and hemophilia A. Analysis of mutant gene distribution over the 
territory by the study of birthplaces of probands and their parents was carried 
out.