- Combined 17 alpha-hydroxylase/17,20-lyase deficiency due to a homozygous 25 BP duplication (NT 4157-4181) at exon 5 in the CYP17 resulting in a premature stop codon predicted by molecular modeling. Martin, R.M., Oliveira, P.S., Costa, E.M., Arnhold, I.J., Mendonca, B.B. Arq. Bras. Endocrinol. Metabol (2008)