Twenty-nail dystrophy (TND) is an autosomal dominantly inherited idiopathic nail dystrophy characterized by excessive longitudinal striations and numerous superficial pits on nails with a typical 'sand papered' rough appearance. It is evident at birth and progresses slowly. It can also be associated with various diseases including lichen planus, alopecia areata, eczema, vitiligo and psoriasis. Peripheral blood chromosome analysis has not been performed in previously reported cases of TND. We report a mother and her 7-year-old daughter with TND. Both of them had a balanced translocation 46, XX, t(6q13;10p13). This may be a coincidental finding or may be related to the gene locus of TND.