TXNRD2 and Aarskog-Scott syndrome, X-linked: With the identification of additional FGD causative genes such as steroidogenic acute regulatory protein (STAR), minichromosome maintenance 4 (MCM4), nicotinamide nucleotide transhydrogenase (NNT), thioredoxin reductase 2 (TXNRD2), cytochrome p450scc (CYP11A1), glutathione peroxidase 1 (GPX1), peroxiredoxin 3 (PRDX3) and sphingosine 1-phosphate lyase (SGPL1), additional phenotypes including permanent or evolving mineralocorticoid deficiency have been reported, which has been recently reviewed elsewhere (14).