19-35033599-A-T

Position:

• chr19-35033599-A-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PP3_Moderate PP5

The NM_001037.5(SCN1B):​c.308A>T​(p.Asp103Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,864 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SCN1B NM_001037.5 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 8.87

Genes affected

SCN1B (HGNC:10586): (sodium voltage-gated channel beta subunit 1) Voltage-gated sodium channels are heteromeric proteins that function in the generation and propagation of action potentials in muscle and neuronal cells. They are composed of one alpha and two beta subunits, where the alpha subunit provides channel activity and the beta-1 subunit modulates the kinetics of channel inactivation. This gene encodes a sodium channel beta-1 subunit. Mutations in this gene result in generalized epilepsy with febrile seizures plus, Brugada syndrome 5, and defects in cardiac conduction. Multiple transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Oct 2009]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a disulfide_bond (size 81) in uniprot entity SCN1B_HUMAN there are 14 pathogenic changes around while only 2 benign (88%) in NM_001037.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.892
• PP5: Variant 19-35033599-A-T is Pathogenic according to our data. Variant chr19-35033599-A-T is described in ClinVar as [Pathogenic]. Clinvar id is 375404.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SCN1B	NM_001037.5	c.308A>T	p.Asp103Val	missense_variant	3/6	ENST00000262631.11
SCN1B	NM_199037.5	c.308A>T	p.Asp103Val	missense_variant	3/3
SCN1B	NM_001321605.2	c.209A>T	p.Asp70Val	missense_variant	3/6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SCN1B	ENST00000262631.11	c.308A>T	p.Asp103Val	missense_variant	3/6	1	NM_001037.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461864 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727228

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Cardiomyopathy Pathogenic:1

Pathogenic, no assertion criteria provided

research

Lupski Lab, Baylor-Hopkins CMG, Baylor College of Medicine

-

This variant was identified in individual with developmental delay, intellectual disability, polymicrogyria, cardiomyopathy, and nystagmus. Dual molecular diagnoses involving POLR1C and SCN1B were identified. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.47
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.58	D;D;.;.;.
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	.;D;D;D;D
M_CAP	Pathogenic	0.47	D
MetaRNN	Pathogenic	0.89	D;D;D;D;D
MetaSVM	Pathogenic	0.82	D
MutationAssessor	Benign	1.8	L;L;L;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.68	T
PROVEAN	Pathogenic	-5.6	D;.;D;.;.
REVEL	Pathogenic	0.88
Sift	Benign	0.073	T;.;D;.;.
Sift4G	Benign	0.10	T;.;D;.;.
Polyphen		1.0	D;D;D;.;.
Vest4		0.96
MutPred		0.64		Loss of disorder (P = 0.0349);Loss of disorder (P = 0.0349);Loss of disorder (P = 0.0349);.;.;
MVP		0.99
MPC		2.0
ClinPred		0.99	D
GERP RS		4.5
Varity_R		0.61
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1057519457; hg19: chr19-35524503;