Table 3.

Characteristics of patients with multiple sarcomeric mutations

Patient	Sex	Age at Dx	Mutations	Clinical notes
A	F	Utero	MYBPC3: c. 1227-13 G>A (intron), E542Q	Heart transplant; sister with DCM
B	F	1	MYBPC3: G490R, IVS30+5G>C	SOB with moderate exertion; brother with HCM (patient C)
C	M	4	MYBPC3: G490R, IVS30+5G>C, TNNI3: T143N, TPM1: S215L	ICD; heart failure class II; sister with HCM (patient B)
D	M	7	MYBPC3: R943X, TNNI3: T143N, TPM1: S215L	ICD; father, paternal aunt, two paternal cousins with HCM
E	F	11	MYH7: R663H, MYH7: A893sp	Fatigue and SOB; myectomy
F	M	17	TNNT2: 287X, MYL2: R120G	ICD; chest pain on exertion; father, paternal grandfather with HCM
G	M	22	TNNI3: T143N, TPM1: S215L	Sister and son (patient D) with HCM. Deceased from colon cancer.
H	M	44	TNNT2: W287stop, MYL2: R120G	Asymptomatic; HCM in son (patient F)

Patients A–F were diagnosed with HCM at ≤18 years of age, while patients G–H were diagnosed at >18 years. Patient A had characteristics of both HCM and DCM and received a heart transplantation before a definitive diagnosis could be established. Decisions to place ICDs were based on traditional clinical factors for primary or secondary prevention, or in one case patient/family preference due to lifestyle considerations, and not based solely on multiple mutations