Congenital non-syndromic anonychia totalis with acroosteolysis.

Mian A, Jorwal P. BMJ Case Rep 2017. doi:10.1136/bcr-2017-222743 Description A 15-year-old boy presented with a history of absence of fingernails and toenails since birth. He was the first born of a non-consanguineous marriage, delivered vaginally at term with normal birth weight. His mother admitted to excessive consumption of opioid analgesics (ethyl morphine derivatives) during all three trimesters of her first pregnancy, which she discontinued subsequently. He was otherwise healthy, with age-appropriate growth, development and intelligence. His parents and two younger siblings were unaffected. Examination revealed complete absence of all 20 fingernails and toenails (figure 1). Tips of digits were soft, with absence of nail folds, but small keratinised nail plates were present in middle toes bilaterally (figure 2). Skin, teeth and hair were normal. Rest of the general physical and systemic examination was unremarkable with no dysmorphic features. Radiography of hands revealed hypoplasia of terminal phalanges involving all digits, suggestive of acroosteolysis (figure 3). Rest of the skeletal survey was normal. Visual acuity and pure tone audiometry were normal. Clinically, the patient was diagnosed with congenital anonychia totalis possibly secondary to teratogenic effect of morphine. Anonychia (absence of nails of fingers and toes) can be acquired or congenital. A search in English language up to July 2017 identified only 21 reported cases of the congenital anonychia. It most often occurs as a part of syndromes with serious limb and skeletal defects such as nail–patella syndrome; ectodermal dysplasia; anonychia–lymphoedema or DOOR (deafness, onychoosteodystrophy, mental retardation)syndrome. Isolated, non-syndromic congenital anonychia is an extremely rare condition, usually following an autosomal recessive inheritance and has been mapped to defects in chromosome 20p13. Analysis of R-spondin 4 (RSPO4) gene (belonging to R-spondin family of proteins) on this locus, in affected individuals, has revealed frameshift, splice site and missense mutations in exon 2. RSPO4 gene product is implicated in Congenital non-syndromic anonychia totalis with acroosteolysis