To the Editor.—
Malalignment of the great toenails is being increasingly recognized as a cause of infantile and childhood onychogryphosis and ingrown toenail.1 We report two sets of monozygotic twins with congenital malalignment of the great toenails in each set.
Report of Cases.—
We have observed two sets of monozygotic twins aged 3 and 8 years. Abnormal great toenails were noted at birth in all four children. However, in both sets of twins, only one sibling had bilateral onychogryphosis; the other sibling had one onychogryphotic nail, the other great toenail was only slightly malaligned and was neither thickened nor dystrophic.
Samman described a dystrophy affecting one or both great toenails that was present at birth.2 The nails are darker and shorter than normal and tend to be pointed laterally. The nails grow slowly, develop transverse ridges, and may be shed. Baran et al3 have suggested that