rs1553947990

Positions:

• chr4-76174176-G-A

Variant summary

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

The NM_005506.4(SCARB2):​c.962C>T​(p.Ser321Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SCARB2 NM_005506.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.53

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]

SCARB2 (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.962C>T	p.Ser321Leu	missense_variant	7/12	ENST00000264896.8	NP_005497.1
SCARB2	NM_001204255.2	c.533C>T	p.Ser178Leu	missense_variant	4/9		NP_001191184.1
SCARB2	XM_047416429.1	c.488C>T	p.Ser163Leu	missense_variant	7/12		XP_047272385.1
SCARB2	XM_047416430.1	c.488C>T	p.Ser163Leu	missense_variant	7/12		XP_047272386.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SCARB2	ENST00000264896.8	c.962C>T	p.Ser321Leu	missense_variant	7/12	1	NM_005506.4	ENSP00000264896.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

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

Nov 15, 2017

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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with SCARB2-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces serine with leucine at codon 321 of the SCARB2 protein (p.Ser321Leu). The serine residue is moderately conserved and there is a large physicochemical difference between serine and leucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.24
BayesDel_addAF	Uncertain	0.096	D
BayesDel_noAF	Benign	-0.10
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.63	D;.;.;.;.;.;.
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D;D;D;D;D;D;D
M_CAP	Benign	0.082	D
MetaRNN	Uncertain	0.73	D;D;D;D;D;D;D
MetaSVM	Uncertain	0.24	D
MutationAssessor	Pathogenic	3.3	M;.;.;.;.;.;.
PrimateAI	Benign	0.44	T
PROVEAN	Pathogenic	-4.5	D;.;.;.;.;D;.
REVEL	Uncertain	0.54
Sift	Uncertain	0.0090	D;.;.;.;.;D;.
Sift4G	Uncertain	0.015	D;.;.;.;.;D;.
Polyphen		0.17	B;.;.;.;.;.;.
Vest4		0.43
MutPred		0.61		Loss of glycosylation at S321 (P = 0.0224);.;Loss of glycosylation at S321 (P = 0.0224);.;.;.;Loss of glycosylation at S321 (P = 0.0224);
MVP		0.85
MPC		0.57
ClinPred		0.99	D
GERP RS		5.5
Varity_R		0.85
gMVP		0.65

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs1553947990; hg19: chr4-77095329;