Dizygotic twins with congenital malalignment of the great toenails: Reappraisal of the pathogenesis

Congenital Malalignment of the Great Toenails: A Review

“…The age at onset was at birth in 25 cases [2, 9, 10-13, 15-18, 21, 22, 24, 25], during the first 2 years of life in 2 cases [2, 20], and later in life in 2 cases [19], whereas it was not specified in 4 cases [3, 8, 14, 23]. Familial occurrence was confirmed in 5 cases [10, 12, 14, 18], likely in 2 cases [11], and negative in 9 cases [2, 13, 15, 16, 25], whereas in the remaining ones it was not specified [3, 8, 9, 17, 19-24]. Three sets of monozygotic twins [11, 21], 2 of dizygotic twins [12, 16], and 2 identical twins of triplets [13] were reported.…”

“…Familial occurrence was confirmed in 5 cases [10, 12, 14, 18], likely in 2 cases [11], and negative in 9 cases [2, 13, 15, 16, 25], whereas in the remaining ones it was not specified [3, 8, 9, 17, 19-24]. Three sets of monozygotic twins [11, 21], 2 of dizygotic twins [12, 16], and 2 identical twins of triplets [13] were reported. Considering those cases for which the gender was specified, 13 females were affected compared to 11 males (female-to-male ratio 1.1: 1).…”

“…As described in Table 2, nail plate thickening [8-12, 14, 16, 19, 22-25], discoloration ranging from brownish-black to green-brown and yellow [2, 8, 10, 11, 14, 16, 18, 19, 25], and transversal grooves or ridges [2, 8, 10, 11, 16, 23-25] were the most frequently observed abnormalities. The involved nails were sometimes shorter and trapezoidal in shape [2, 22, 23].…”

Acquired Congenital Malalignment of the Great Toenails

“…intrauterine or vascular insult during fetal growth) [6]. A new hypothesis by Chaniotakis et al [6] suggested desynchronization in growth between the nail and the distal phalanx of the hallux leading to larger nail plates, which must grow laterally to fit into the underlying bony space.…”

Congenital Malalignment of the Great Toenails

“…Malalignment of the great toenails is being increasingly recognized as a cause of infantile and childhood onychogryphosis and ingrown toenail [1]. There has been debate as to whether the condition is inherited or acquired in utero secondary to improper fetal positioning [2,3]. We report a 6 month-old male baby with congenital malalignment of the great toenails.…”