A rare disorder characterized by mirror polydactyly, vertebral hypersegmentation and severe congenital limb deficiencies. Duodenal atresia and absent thymus were also reported. So far, it has been described in four unrelated infants identified through a congenital malformation screening program carried out in Spain. The prevalence was estimated at around 1 in 330,000. The etiology is unknown but it was suggested that the syndrome is caused by defective expression of a developmental control gene.

Missing or malformed long bones of the extremities with the distal parts (such as hands and/or feet) connected to the variably shortened or even absent extremity, leading to a flipper-like appearance, as opposed to other forms of limb malformations were either the hole limb is missing (such as amelia), or the distal part of a limb is absent (peromelia).