rs777270813

Positions:

• chr4-76166260-T-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_005506.4(SCARB2):​c.1229A>T​(p.Tyr410Phe) variant causes a missense change. The variant allele was found at a frequency of 0.0000123 in 1,461,874 control chromosomes in the GnomAD database, with no homozygous occurrence. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: SCARB2 NM_005506.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.76

Genes affected

SCARB2 (HGNC:1665): (scavenger receptor class B member 2) The protein encoded by this gene is a type III glycoprotein that is located primarily in limiting membranes of lysosomes and endosomes. Earlier studies in mice and rat suggested that this protein may participate in membrane transportation and the reorganization of endosomal/lysosomal compartment. The protein deficiency in mice was reported to impair cell membrane transport processes and cause pelvic junction obstruction, deafness, and peripheral neuropathy. Further studies in human showed that this protein is a ubiquitously expressed protein and that it is involved in the pathogenesis of HFMD (hand, foot, and mouth disease) caused by enterovirus-71 and possibly by coxsackievirus A16. Mutations in this gene caused an autosomal recessive progressive myoclonic epilepsy-4 (EPM4), also known as action myoclonus-renal failure syndrome (AMRF). Alternatively spliced transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Feb 2011]

(HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SCARB2	NM_005506.4	c.1229A>T	p.Tyr410Phe	missense_variant	10/12	ENST00000264896.8	NP_005497.1
SCARB2	NM_001204255.2	c.800A>T	p.Tyr267Phe	missense_variant	7/9		NP_001191184.1
SCARB2	XM_047416429.1	c.755A>T	p.Tyr252Phe	missense_variant	10/12		XP_047272385.1
SCARB2	XM_047416430.1	c.755A>T	p.Tyr252Phe	missense_variant	10/12		XP_047272386.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCARB2	ENST00000264896.8	c.1229A>T	p.Tyr410Phe	missense_variant	10/12	1	NM_005506.4	ENSP00000264896	P4
	ENST00000651366.1	n.102+16994T>A		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251398 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135860

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000123 AC: 18 AN: 1461874 Hom.: 0 Cov.: 30 AF XY: 0.00000825 AC XY: 6 AN XY: 727238

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000252

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000540

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Progressive myoclonic epilepsy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 15, 2022

This sequence change replaces tyrosine, which is neutral and polar, with phenylalanine, which is neutral and non-polar, at codon 410 of the SCARB2 protein (p.Tyr410Phe). This variant is present in population databases (rs777270813, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with SCARB2-related conditions. ClinVar contains an entry for this variant (Variation ID: 531800). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.10	T
BayesDel_noAF	Benign	-0.22
CADD	Benign	18
DANN	Benign	0.97
DEOGEN2	Benign	0.23	T;.;.;.;.;.;.;.
Eigen	Benign	0.042
Eigen_PC	Uncertain	0.23
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.89	D;D;D;D;D;D;D;D
M_CAP	Benign	0.018	T
MetaRNN	Uncertain	0.43	T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.70	T
MutationAssessor	Benign	1.2	L;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.52	T
PROVEAN	Benign	-1.3	N;.;.;.;.;.;N;.
REVEL	Benign	0.23
Sift	Benign	0.48	T;.;.;.;.;.;T;.
Sift4G	Benign	0.55	T;.;.;.;.;.;T;.
Polyphen		0.0020	B;.;.;.;.;.;.;.
Vest4		0.43
MutPred		0.80		Gain of glycosylation at Y410 (P = 0.0953);.;Gain of glycosylation at Y410 (P = 0.0953);.;.;.;.;Gain of glycosylation at Y410 (P = 0.0953);
MVP		0.19
MPC		0.22
ClinPred		0.38	T
GERP RS		6.1
Varity_R		0.66
gMVP		0.83

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: rs777270813; hg19: chr4-77087413;