The heat-shock protein beta-1 (HSPB1) is one of small heat-shock proteins that play an im-portant role in cell functioning by promoting correct folding of other proteins. The HSPB1 mutations are known to cause distal Hereditary Motor Neuropathy type 2B (dHMN2B) and Charcot-Marie-Tooth disease type 2F (CMT2F). More than 30 different mutations in the HSPB1 have been found in patients with CMT2F and dHMN2B. There are cases of the Thr151Ile HSPB1 mutation described in 4 countries: Croatia, Japan, France and Poland. In this paper we present a Polish family with p.Thr151Ile mutation causing distal hereditary motor neuropathy. A 48-year-old male patient presented progressive bilateral lower limb weakness and gait difficulty of typical onset. The presentation of the disease in his daughter, who carries the same mutation is yet uncertain. She has currently no clinical symptoms of the disease but registered mild muscle damage in EMG with correct conduction parameter in EMG.

The acoustic climate assessment needed for the selection of solutions (technical, legal and organisational), which will help to minimise the acoustic hazards in the analysed areas, is realised on the basis of acoustic maps. The reference computational algorithms, assigned to them, require very thorough preparation of input data for the considered noise source model representing - in the best possible way - the acoustic climate. These input data are burdened with certain uncertainties in this class of computational tasks. The uncertainties are related to the problem of selecting proper argument values (from the interval of their possible variability) for the modelled processes. This situation has a direct influence on the uncertainty of acoustic maps.

The idea of applying the interval arithmetic for the assessment of acoustic models uncertainty is formulated in this paper. The computational formalism assigned to the interval arithmetic was discussed. The rules of interval estimations for the model solutions determining the sound level distribution around the analysed noise source - caused by possible errors in the input data - were presented. The application of this formalism was illustrated in uncertainty assessments of modelling acoustic influences of the railway noise linear source on the environment.