Objective: To estimate the normal values of precursors of endogenic cholesterol synthesis (lathosterol, desmosterol, lanosterol) as well as of phytosterols (campesterol, sitosterol) in healthy children or adults and evaluate their diagnostic significance during dietary treatment of children patients suffering from familial hypercholesterolemia. Design: Retrospective analysis of data from routine examination of above mentioned markers during diagnostics, introducing of treatment and its monitoring within last 3 years in metabolic outpatient department. Material and methods: GC/MS estimation of fasting plasmatic values in children patients as well as in healthy control groups of children and adults. Results: Reference values for lathosterol in plasma: a) 5–6 yrs girls 4.0 ± 0.78 µmol/l, boys 3.7 ± 0.92 µmol/l; b) 7–10 yrs girls 6.03 ± 0.63 µmol/l, boys 6.0 ± 0.60 µmol/l; c) 11–15 yrs girls 7,17 ± 0,45 µmol/l, boys 6.13 ± 0.51 µmol/l; d) 16–18 yrs girls 5.66 ± 0.82 µmol/l, boys 6.31 ± 1.3 µmol/l. Adults (blood donnors 20–65 yrs): women 6.36 ± 0.7 µmol/l, men 7.44 ± 1.06 µmol/l. Campesterol: a) 5–6 yrs girls 9.89 ± 1.18 µmol/l, boys 9.73 ± 1.38 µmol/l; b) 7–10 yrs girls 10.95 ± 0.95 µmol/l, boys 9.65 ± 0.9 µmol/l; c) 11–15 yrs girls 10.45 ± 0.68 µmol/l, boys 9.2 ± 0.77 µmol/l; 16–18 yrs girls 10.1 ± 1.24 µmol/l, boys 15.67 ± 1.96 µmol/l; Adults: women 10.7 ± 0.4 µmol/l, men 9.1 ± 1.61 µmol/l. Sitosterol: a) 5–6 yrs girls 7.45 ± 0.87 µmol/l, boys 7.5 ± 1.1 µmol/l; b) 7–10 yrs girls 7.7 ± 0.7 µmol/l, boys 7.2 ± 1.0 µmol/l, c) 11–15 yrs girls 7.1 ± 1.5 µmol/l, boys 7.2 ± 1.4 µmol/l; d) 16–18 yrs girls 5.78 ± 0.92 µmol/l, boys 7.36 ± 1.45 µmol/l. Adults women: 8.65 ± 0.77 µmol/l, men 7,72 ± 1,19 µmol/l. During strict low cholesterol dietary treatment (200 mg/d) of familial hypercholesterolemias the moderate increase of lathosterol mean values was observed with similar changes for desmosterol. Campesterol and sitosterol were not significantely changed. Conclusions: Precursors of cholesterol synthesis and phytosterols are useful metabolites for differentiation of patients with familial hypercholesterolemia and they are helpful in controlling of dietary treatment.

        Key words: lathosterol, desmostereol, campesterol, sitosterol, low cholesterol dietary treatment, familial hypercholesterolemia in children