A complement C5 gene mutation, c.754G>A:p.A252T, is common in the Western Cape, South Africa and found to be homozygous in seven percent of Black African meningococcal disease cases.
We postulate that the C5 defect is not the sole cause of Leiner's disease as has been suggested, but that hypogammaglobulinaemia or other lymphoid deficiency is also required for its expression.