Table.

Eleven Patients With Poor Pacemaker Capture of 136 Reviewed at Texas Children's Hospital

Case	Sex	Age at Implant in Years and Device	Phenotype	Sensing Issue	Capture Issue	SCN5A SNP or Mutation	NaV1.5*	PloyPhen-2
1	F	4.7 PM	SND, atrial flutter; alive	A	A+V	G to A substitution at the donor splice site of intron 5 (IVS5+1G>A)	Truncation to 204 aa	N/A
2	M	Newborn PM	SND, AT, AVB, LVNC, VT, loss of V capture; alive	...	V	Nucleotide substitution (5227G>A)	G1743R (trafficking defect)	Probably damaging
3	M	1.6 PM	SND, atrial flutter/fibrillation, VT, loss of V capture; died	A+V	A+V	Nucleotide substitution (4534C>T)	R1512W (impaired fast inactivation)	Probably damaging
4	M	15.6 PM	SND, atrial flutter; alive	A	A	Nucleotide substitution (3823G>A)	D1275N (reduced INa)	Probably damaging
5	F	11.8 ICD	SND, atrial flutter/fibrillation, VT; alive	A	A+V	Nucleotide substitution (5770G>A)†	A1924T (impaired activation)	Possibly damaging or benign
6	F	12.3 ICD	SND, AT; alive	V	A+V	Nucleotide substitution (5770G>A)†	A1924T (impaired activation)	Possibly damaging or benign
7	F	5.9 PM	SND, atrial flutter; alive	...	V	Deletion of C at position 100 in exon 2 (100delC)	Truncation to 95 aa	N/A
...	F	1.6 PM	LVNC, LQT, AT, VT, loss of V capture; died	...	A	SNPs: 1673A>G, 100C>T	N/A	N/A
...	M	17.2 PM	Sinus pauses, intermittent AVB, A flutter; alive	A	A	SNPs: 87A>G, IVS5-86G>A, IVS27_28ins28, 3183A>G, IVS21+73G>A, 5457T>C, 5844C>T	N/A	N/A
...	M	12.5 PM	SND, AT; alive	A	A	None	N/A	N/A
...	F	6.8 PM	SND, AVB; alive	V	V	(No genetic testing)	N/A	N/A

A indicates atrial; AT, atrial tachycardia; AVB, atrioventricular block; ICD, implantable cardioverter defibrillator; LQT, long QT; LVNC, left ventricular noncompaction; N/A, not applicable; PM, pacemaker; SND, sinus node dysfunction; SNP, single-nucleotide polymorphism; V, ventricular; and VT, ventricular tachycardia.

^*Full length Na_V1.5 is 2016 amino acids (aa) long.

^†Homozygous.