Iso-Kikuchi syndrome in an Italian new-born with Y-shaped bifurcation of the index fingers

Iso-Kikuchi Syndrome in A Newborn and His Mother

“…Iso-Kikuchi syndrome or congenital onychodysplasia of the index fingers is a rare entity that affects primarily the nails of both index fingers and can compromise the phalanges. It produces total anonychia or dysplasia of the nails [1][2][3]. In 1969 Iso described seven cases from his own practice and collected two others from the literature with anomalies in the nails of the index fingers which included anonychia, micronychia and polyonychia.…”

A 10-year-old Girl with a Melon Seed-like Nail on her Index Finger: A Quiz

“…Iso-Kikuchi syndrome, commonly known as congenital onychodysplasia of the index finger was originally identified by Iso and Kikuchi ( 1 , 2 ). The incidence rate worldwide is approximately 4.2 cases/100,000 births ( 3 ). In China Iso-Kikuchi syndrome is often underdiagnosed; we have described here the second sporadic Chinese case and the first Chinese paediatric case ( 4 )…”

“…Different pathophysiological theories have been proposed to explain Iso-Kikuchi syndrome, including foetal disorders affecting the palmar digital artery with in utero ischaemic changes, in utero alterations of the crescent-shaped distal phalanx, and foetal exposure to teratogens, in particular antiepileptic drugs ( 3 , 7 ).…”

Iso‐Kikuchi syndrome with Y‐shaped bifurcation of the distal phalanx of the index fingers

“…Several clinical criteria have been proposed since then [3], including congenital occurrence with sporadic or hereditary transmission, unilateral or bilateral involvement of the fingers (mainly the index fingers but other fingers and even toes may be affected), variability in nail appearance, and bone malformations. Different pathogenic theories have been proposed to explain Iso-Kikuchi syndrome [4,5], including fetal disorders affecting the palmar digital artery with in utero ischemic changes, in utero alterations of the crescent-shaped distal phalanx, and fetal exposure to teratogens, in particular antiepileptic drugs. Genetic mutations with an autosomal dominant transmission pattern might also be implicated, but no loci have been identified.…”