Genetic Variant BLOC1S1:p.Ala55Val (chr12-55716951-C-T) – ACMG Classification: Uncertain_significance (4 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_001487.4(BLOC1S1):c.164C>T(p.Ala55Val) variant causes a missense change. The variant allele was found at a frequency of 0.000000694 in 1,440,844 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 Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

BLOC1S1
NM_001487.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.70

Variant links:

Genes affected

BLOC1S1 (HGNC:4200): (biogenesis of lysosomal organelles complex 1 subunit 1) BLOC1S1 is a component of the ubiquitously expressed BLOC1 multisubunit protein complex. BLOC1 is required for normal biogenesis of specialized organelles of the endosomal-lysosomal system, such as melanosomes and platelet dense granules (Starcevic and Dell'Angelica, 2004 [PubMed 15102850]).[supplied by OMIM, Mar 2008]

BLOC1S1 links:

ENSG00000258311 (HGNC:):

ENSG00000258311 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.894

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BLOC1S1	NM_001487.4 link	c.164C>T	p.Ala55Val	missense_variant	Exon 2 of 4	ENST00000548925.6	NP_001478.2	P78537-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BLOC1S1	ENST00000548925.6 link	c.164C>T	p.Ala55Val	missense_variant	Exon 2 of 4	1	NM_001487.4	ENSP00000447537.1		P78537-1
ENSG00000258311	ENST00000550412.5 link	c.164C>T	p.Ala55Val	missense_variant	Exon 2 of 4	2		ENSP00000447650.1		F8W036

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.94e-7

AC:

AN:

1440844

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

716452

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

9.06e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

May 18, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.164C>T (p.A55V) alteration is located in exon 2 (coding exon 2) of the BLOC1S1 gene. This alteration results from a C to T substitution at nucleotide position 164, causing the alanine (A) at amino acid position 55 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.86

BayesDel_addAF

Uncertain

0.12

BayesDel_noAF

Uncertain

-0.070

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.39

.;T;T

Eigen

Uncertain

0.59

Eigen_PC

Uncertain

0.63

FATHMM_MKL

Uncertain

0.85

LIST_S2

Uncertain

0.92

D;D;D

M_CAP

Benign

0.034

MetaRNN

Pathogenic

0.89

D;D;D

MetaSVM

Benign

-0.85

MutationAssessor

Uncertain

2.6

.;M;.

PrimateAI

Uncertain

0.78

PROVEAN

Uncertain

-3.6

D;D;D

REVEL

Benign

0.22

Sift

Uncertain

0.0030

D;D;D

Sift4G

Benign

0.081

T;D;T

Polyphen

0.98

D;P;D

Vest4

0.82

MutPred

0.79

Loss of disorder (P = 0.0705);Loss of disorder (P = 0.0705);Loss of disorder (P = 0.0705);

MVP

0.70

MPC

0.16

ClinPred

1.0

GERP RS

5.1

Varity_R

0.71

gMVP

0.69

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

No publications associated with this variant yet.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over