Figure 5.

A European family with multiplex SLE-related mortality and low C4 levels (E94). (A) A three-generation family tree. E94P and S4 passed away with lupus nephritis and complications. (B) TaqI RFLP to show RCCX modular structures for six subjects of the E94 family including the index patient E94P, two siblings (S1 and S2), three niece/nephew plus two control subjects (C01 and C02). Note that E94P, S1 and N3 each contained an unusual short-short (SS) haplotype for RCCX that had CYP21B-CYP21B configurations ( Table 2 ). (C) PshAI/PvuII RFLP to show the relative dosages of C4A and C4B genes for subjects shown in panel (B), except E94P as her C4A and C4B genes were determined by real-time PCR. (D) Long-range mapping of the RCCX haplotypes by PmeI-digested genomic DNA in agarose plugs, resolved by pulsed-field gel electrophoresis and hybridized to radioactive probes specific for RCCX genes. DNA plugs for four members of the E94 family were prepared together with four unrelated controls (C03-C07). Subject N3 possessed the LL and SS haplotypes. (E) Immunofixation of EDTA-plasma to show C4A and C4B protein variants and their relative expression levels. Subject N3 has similar protein levels of C4A3 and C4B1, although she had LL/SS haplotypes with three copies of C4B gene and one copy of C4A. (F) DNA sequences at exon 28-intron 28 splice junction for six members of the E94 family, plus a C4 complete deficiency subject with identical HLA haplotypes (C4DF1), and a normal control (GN3104). Subjects S1, P and N3 had double sequences at the intron 28 splice junction donor site (marked by an arrow for E94P). C4DF1 has homozygous mutations at the same locations.