Table 1.

Summary of genetic findings.

Pedigree	Gene	Chr	Transcript	Genomic Position GRCh37 (hg19)	Nucleotide Change	Amino Acid Change	Max ExAC MAF*	Max gnomAD MAF*	dbSNP	Variant Classification†
A	SOS1	2	NM_005633.3	39281904	c.571G>A	p.(Glu191Lys)	0	0.0001147 (AFR)(G)	rs886041241	VUS
	FLNC	7	NM_001458.4	128489028	c.4926_4927 insACGTCACA	p.(Val1643Thrfs*26)	0	0.000009182 (NFE)(E)	Not found	LP
	TTN	2	NM_001267550.2	179413874	c.92478dupA	p.(Val30827Serfs*22)	0	0	Not found	LP
B	SOS1	2	NM_005633.3	39249749	c.1820T>C	p.(Ile607Thr)	0.00003006 (NFE)	0.00002654 (NFE)(E)	rs758699499	VUS
		2	NM_005633.3	39233616	c.2728G>C	p.(Asp910His)	0.00006061 (SAS)	0.00009806 (SAS)(E)	rs369277679	VUS
C	SOS1	2	NM_005633.3	39240612	c.2156G>C	p.(Gly719Ala)	0.0005556 (NFE)	0.0003426 (NFE)(E+G)	rs200794965	VUS
D	SOS1	2	NM_005633.3	39239427	c.2230A>G	p.(Arg744Gly)	0	0	Not found	VUS
E	SOS1	2	NM_005633.3	39213366	c.3601C>T	p.(Arg1201Trp)	0.00006058 (SAS)	0.00003266 (SAS)(E)	rs752395541	VUS
	MYH6	14	NM_002471.3	23853739	c.5476_5477 delGGinsAA	p.(Gly1826Asn)	0	0	rs878854502	VUS

^*The maximum non-founder minor allele frequency (MAF) and associated population for each variant is reported. A MAF of 0 implies absence of the variant from Exome Aggregation Consortium (ExAC) / Genome Aggregation Database (gnomAD) and sufficient coverage of the genomic position. Reported gnomAD results include both exomes (E) and genomes (G) when available. AFR, African; NFE, non-Finnish European; SAS, South Asian

^†Variants were adjudicated using the DCM Consortium and DCM Precision Medicine approach to DCM variant interpretation²⁴, refined from current American College of Medical Genetics (ACMG) / ClinGen guidelines²⁵