Isolated anonychia without any associated phenotypical disturbances is one of the rarest anomalies of congenital nail disorders. Some or all fingers of the hands or feet could be affected. Anonychia can be encountered in dermatologic disorders like pemphigus, lichen planus, epidermolysis bullosa; it can also be seen as a component of some syndromes like Nail-Patella and Cooks syndromes. We present a sister couple in whom all fingernails and toenails were lacking without any additional physical sign. A fragile chromosomal site was also encountered in peripheral chromosome analysis in the long arm of the chromosome 10 in both of the cases. (C) 2004 Elsevier SAS. All rights reserved.