PTPN11 and Noonan syndrome: In biopsy 4D25, PTPN11 c.1504T > A (p.Ser502Thr – Noonan syndrome) was called as a single-nucleotide variant, but on validation, it was identified as a double-nucleotide substitution c.1504_1505delTCinsAA (p.Ser502Lys).