PTPN11 and Noonan syndrome: Similarly, mutations in CHD7 (MIM: 608892) (encoding a chromatin remodeler) cause CHARGE syndrome (MIM: 214800),67 while mutations in PTPN11 (MIM: 176876) (encoding a protein tyrosine phosphatase involved in cell signaling) lead to Noonan syndrome (NS1 [MIM: 163950]).68