Table 1:

Incidence of Specific Cancer Types in RASopathies. ALL: Acute lymphocytic leukemia; AML: Acute myeloid leukemia; JMML: Juvenile myelomonocytic leukemia

RASopathy	Most Common Cancer Type(s)	Approximate Incidence
Costello syndrome (HRAS)	General	~40-fold increase over general population
	Bladder cancer	~1.5%
	Neuroblastoma	~2%
	Rhabdomyosarcoma	~7%
Noonan syndrome (PTPN11; e.g., codon 61 or T73I), (KRAS; e.g., T58I)	JMML, rhabdomyosarcoma, ALL, neuroblastoma, brain tumors	~8-fold increase over general population
Noonan syndrome (SOS1, RAF1, RIT1, SOS2, RRAS, LZTR1, BRAF)	Case reports of ALL, neuroblastoma, rhabdomyosarcoma	Unclear risk
Noonan syndrome with multiple lentigines (PTPN11, RAF1, BRAF, MAP2K1)	Case reports of AML, ALL, neuroblastoma, melanoma	Possibly mildly elevated, although unclear how much so
Noonan syndrome with loose anagen hair (PPPC1B, SHOC2)	Case reports of neuroblastoma, myelofibrosis, t cell lymphoma	Possibly mildly elevated, although unclear how much so
CBL syndrome (CBL)	JMML	Elevated, but unclear how much so
Cardiofaciocutaneous syndrome (BRAF, MAP2K1, MAP2K2, KRAS)	Case reports of rhabdomyosarcoma, ALL, lymphoma	Possibly mildly elevated, although unclear how much so
Legius syndrome (SPRED1)	Case reports of pediatric leukemias	Not believed to be elevated