Mutation analysis.

Mutation analysis of the patient 1 (A) and patient 2 (B) with ADA deficiency and the reversion in T-cell lines from patient 1 (C) and patient 2 (D). Arrows indicate mutation sites. Each mutation was confirmed by digestion of the PCR fragment with a restriction enzyme indicated at the left end of each lower column. Each enzyme cuts only the fragment including the mutation, and both patterns with (+) and without (−) the enzyme are shown. Paternally inherited mutation of patient 1 and maternally inherited mutation of patient 2 were reversed. Digestion studies verified the reversions. An asterisk indicates the sample obtained from the T-cell line. Molecular marker used is φX 174HaeIII digested.