Background: We report here two families illustrating the intrafamilial phenotypic variety of the non-classical 21-hydroxylase deficiency and other discrepancies between clinical and hormonal data.
Patients, methods and results: The index case in the first family had a mild hirsutism which appeared peripuberally and basal 17-hydroxyprogesterone over the measurement limit. One of her sister, without hair excess, had the same biochemical abnormality. The index case in the second family was detected at five years because of early appearance of public hair and basal 17-hydroxyprogesterone over the measurement limit. One of her siblings, a 16-year old girl, was also diagnosed of mild hirsutism and increased levels of basal and post-stimulation 17-hydroxyprogesterone.
Conclusions: The association of marked biochemical abnormalities with scarce or no clinical expression in the first family and the different presentation form of both cases in the second family suggest that there is something else than the mutation in the CYP 21B gene in the non-classic deficiency of 21-hydroxylase.