Tibial hemimelia is a rare congenital anomaly, occurring approximately in 1 per 1million live birth and consisting of aplastic/hypoplastic tibia with relatively intact fibula. The widely used classification was proposed by Jones and based on radiological description: type I: tibia absent, type II distal tibia not seen, type III proximal tibia not seen, type IV tibio-fibular diastases. This congenital deformity can be unilateral or bilateral and isolated, or unilateral or bilateral and associated with other malformation witch raise its genetic cause.

We are reporting the cases of two monozigotic twins reflecting the “intragenotic” expression variability of the syndrome of tibial aplasia and ectrodactyly. The two monozigotic female twins are born after an unremarkable first pregnancy and delivery. Family history was positive for malformations.(syndactily, split hand, phocomelia(elbow) and hip dyspasia)

Twin 1: Left leg: tibial aplasia type Ia, short femur, absent patella. Right leg: tibial aplasia type IV, clubfoot, hypoplasia of the internal ray. Left hand: split hand.

Twin 2: Left leg: nornal. Right leg: tibial aplasia type II, clubfoot. Left hand: split hand.

Most of the cases are unilateral and sporadic. 4 autosomal dominant tibial hemimelia syndromes are described

tibial hemimelia-foot polydactyly-triphangeal thumbs syndrome,

tibial hemimelia diplopodia syndrome,

tibial hemimelia-split-hand foot syndrome,

tibial hemimelia micromelia-oigonobrachycephaly syndrome.

This is the first documennted case of monozigotic twins affected by the Tibial hemimelia-split-hand foot syndrome. Their clinical presentation demonstrates that the phenotypic manifestations are highly variable.