A pair of sibs with tibial hemimelia born to phenotypically normal parents

Tibial hemimelia is a rare congenital anomaly characterized by deficiency of the tibia with relatively intact fibula. Tibial hemimelia is identified as a solitary disorder, or a part of more complex malformation syndromes. Although the majority of cases with tibial hemimelia are sporadic, affected families with possible autosomal dominant or autosomal recessive inheritance have been reported. Here we report a pair of sibs, 6- and 2-year-old Japanese boys, with tibial hemimelia born to unrelated, phenotypically normal parents. The type of tibial hemimelia and associated malformations of hands and feet was quite different between the brothers. The elder brother was compatible with the Gollop-Wolfgang complex, and the younger brother with tibial agenesis-ectrodactyly syndrome. Screening of mutation by direct sequencing of candidate genes including Sonic hedgehog, HOXD-11, and HOXD-12 was unable to identify a disease-causing mutation.