SSX3 and small cell osteogenic sarcoma: We also identified two additional rare variants: c.459G>A, g.9116G>C in the SSX3 gene (locus Xp11.23) in patients with SCOS (P13L, P65P); and variant chrX:147088321C>T in the FMR1NB gene (locus Xq27.3‐q28) in patients with postmeiotic arrest (Table 3).