Figure 1.

Inverse shifting‐PCR (IS‐PCR) suggested a structural abnormality in the proband's F8 intron 1. (a) Family pedigree. Proband (III‐3) is indicated by an arrow. The proband's mother (II‐2) showed reduced FVIII activity (FVIII:C = 56.3 IU/dL) and had bleeding symptoms at the time of surgery. The proband's father (II‐1) and maternal grandparents (I‐1 and I‐2) did not have any bleeding tendency. (b) Recurrent inversion analysis with IS‐PCR. N, normal male control; P, proband; M, mother. In Inv1 diagnostic test, the proband's PCR product was not observed (expected band sizes are normal: 316 bp and Inv1: 281 bp, respectively). Other tests showed a pattern similar to that in a normal control (Inv22 diagnostic test: 498 bp, Inv22 complementary test: 489 and 411 bp)