X-linked adrenoleukodystrophy (X-ALD) is a relatively common world spread disease characterized by significant clinical heterogeneity. Clinico-biochemical examination in the Medico-genetic research center identified, 20 X-ALD cases in 17 families over 5 years. Prevalence of children (60%) and adolescence (25%) cerebral forms is explained, in part, by patients referring for medical-genetic counseling. Adrenomyeloneuropathy was diagnosed in one patient. In two healthy siblings presymptomatic stage was found. A main X-ALD biochemical marker is an increase of very long chain fatty acids (VLCFA) level, which does not depend on clinical form of the disease. Most interesting appeared to be a family including 5 patients in 3 generations with intrafamilial combination of childhood and adolescence cerebral forms, and atypically mild disease course in proband. Regarding symptoms of childhood and adolescence cerebral forms, attention has been drawn to 3 patients with tics, which mask organic nature of the disease on its initial stage. X-ALD is so far incurable, but its timely diagnosis provides an adequate medico-genetic help on the base of modern prenatal diagnosis.