Figure 2.

A novel nonsense mutation in the human CYP11B1 gene. (a) Pedigree of a large Saudi family with CYP11B1 gene mutation. Three brothers are diagnosed with steroid 11β-hydroxylase deficient congenital adrenal hyperplasia. One died at 30 months of age due to heart failure. Both parents and three siblings are unaffected. (b) Sequence analysis shows a biallelic c.780 G>A mutation in exon 4 of the CYP11B1 gene in both patients from the family. The mutation creates a premature stop codon TGA. The mutation is indicated by an arrow. The parents refused to donate blood for genetic testing, but they are likely heterozygous carriers.