LAUSR

DEAR EDITOR, Pure hair and nail ectodermal dysplasia (PHNED) is an autosomal recessive ectodermal dysplasia (ED) that is characterized by hypotrichosis and nail dystrophy only, without further ectodermal or nonectodermal alterations. To date, homozygous mutations in three genes have been reported to cause PHNED: KRT85, encoding keratin, type II cuticular Hb5 like; KRT74, encoding keratin, type II cytoskeletal 74; and HOXC13, encoding homeobox C13. Here, we studied the genetic basis of PHNED in an Iranian family, displaying double consanguinity (Fig. 1a–g). Phenotypically, two affected sisters showed hypotrichosis of the scalp, absence of body hair and nail dysplasia. In the clinical pictures provided, they had their scalp hair shaved for aesthetic reasons (Fig. 1b, e). Both sisters exhibited nail dysplasia in all nails of both hands and feet, comprising koilonychia, onychodystrophy and, additionally, nail discoloration (Fig. 1c, d, f, g). Interestingly, they were additionally affected by lacrimal duct obstruction (LDO) from birth. To the best of our knowledge, LDO has not been previously described in association with PHNED and therefore, there was doubt regarding the diagnosis of PHNED. To confirm the