Severe limb deficiencies, vertebral hypersegmentation, and mirror polydactyly: two additional cases that expand the phenotype to a more generalized effect on blastogenesis.

We report on 2 unrelated fetuses with a multiple congenital anomaly pattern of severe limb deficiencies, vertebral/rib alterations, and mirror polydactyly similar to that described previously by us [Urioste et al., Hum Genet 97:214-217, 1996]. In addition, the two cases we present here have a more extense alteration of blastogenesis, expanding the phenotype of the cases previously reported. We have suggested [Urioste et al., Hum Genet 97:214-217, 1996] that this condition may be caused by a mutation in a developmental control gene that affects body-plan organization. The minimal estimate of the prevalence of this new entity in our population (the Spanish Collaborative Study of Congenital Malformations, ECEMC) is 3.0/ 1,000,000 live births.