Familial occurrence of bifid femur and monodactylous ectrodactyly

Two brothers each hada one normal upper limb; one had tridactylous ectrodactyly of one hand with normal forearm bones; the other had monodactyly of one hand with absent ipsilateral ulna. Both had monodactyly of the feet, absence of the tibiae, and unilateral bifurcation of the femur. A sister of the paternal grandfather was purportedly similarly affected. Since her parents and the father and paternal grandfather of the affected boys were normal, the pattern of inheritance of the trait in this family is presently unclear.