RESUMEN
Sweat osmolality pattern was studied in Indian sub population of both controls and patients with congenital diseases. A Normal range for sweat osmolality was established for different age groups and sex (100-150 mmols/kg) and compared with the patients, who were clinically diagnosed as cystic fibrosis, Down's syndrome and mentally retarded cases. The study has revealed that sweat osmolality varies according to age and sex in normal population implying the effect of endocrinological changes associated with the onset of puberty. Further, it was also observed that an elevated sweat osmolality is not unique to cystic fibrosis alone, but seen among the Down's syndrome and some of the mentally retarded cases where in the etiology is traced to the inborn errors of metabolism.