The clonal expansion of some PAE mutations in the testis with age also results in more mutant sperm in older individuals and an increased incidence of the associated congenital disorder with paternal age, as observed, for example, for achondroplasia (ACH), a growth disorder with a defect in FGFR3 signaling (Risch et al. 1987; Tiemann-Boege et al. 2002; Shinde et al. 2013). The gene discussed is FGFR3; the disease is achondroplasia.