in two boys, but clinical and laboratory assessment confirmed the diagnosis of central precocious puberty. The proband in Family A and her brother (Patients III-1 and III-2 in Fig. 1) have esotropia, which is a minor diagnostic criterion for the Prader–Willi syndrome.28 The boy also has a renal cyst. Neither child has any other features of the syndrome, nor do any of the other affected patients. Additional details are available in the Supplementary Appendix.
