15-45587511-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_012388.4(BLOC1S6):c.68G>A(p.Gly23Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000254 in 1,576,002 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. G23G) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: BLOC1S6 NM_012388.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.01

Genes affected

BLOC1S6 (HGNC:8549): (biogenesis of lysosomal organelles complex 1 subunit 6) The protein encoded by this gene may play a role in intracellular vesicle trafficking. It interacts with Syntaxin 13 which mediates intracellular membrane fusion. Mutations in this gene cause symptoms associated with Hermansky-Pudlak syndrome-9. Alternative splicing results in multiple transcript variants. A pseudogene related to this gene is located on the X chromosome. [provided by RefSeq, Aug 2015]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.06423259).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BLOC1S6	NM_012388.4	c.68G>A	p.Gly23Glu	missense_variant	1/5	ENST00000220531.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BLOC1S6	ENST00000220531.9	c.68G>A	p.Gly23Glu	missense_variant	1/5	1	NM_012388.4	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152242 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000211 AC: 3 AN: 1423642 Hom.: 0 Cov.: 31 AF XY: 0.00000426 AC XY: 3 AN XY: 704956

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: 0.0000245

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000656 AC: 1 AN: 152360 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74498

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000653

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hermansky-Pudlak syndrome 9 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

May 22, 2022

This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 23 of the BLOC1S6 protein (p.Gly23Glu). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with BLOC1S6-related conditions. 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. -

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 06, 2023

The c.68G>A (p.G23E) alteration is located in exon 1 (coding exon 1) of the BLOC1S6 gene. This alteration results from a G to A substitution at nucleotide position 68, causing the glycine (G) at amino acid position 23 to be replaced by a glutamic acid (E). 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	Benign	0.080
BayesDel_addAF	Benign	-0.23	T
BayesDel_noAF	Benign	-0.56
Cadd	Benign	17
Dann	Benign	0.92
DEOGEN2	Benign	0.19	T;T;T
Eigen	Benign	-0.83
Eigen_PC	Benign	-0.75
FATHMM_MKL	Benign	0.17	N
LIST_S2	Benign	0.65	T;T;T
M_CAP	Benign	0.0030	T
MetaRNN	Benign	0.064	T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.7	L;.;.
MutationTaster	Benign	1.0	N;N;N;N;N
PrimateAI	Benign	0.44	T
PROVEAN	Benign	-0.49	N;N;N
REVEL	Benign	0.025
Sift	Benign	0.85	T;T;T
Sift4G	Benign	1.0	T;T;T
Polyphen		0.0	B;.;.
Vest4		0.13
MutPred		0.14		Gain of solvent accessibility (P = 0.024);Gain of solvent accessibility (P = 0.024);Gain of solvent accessibility (P = 0.024);
MVP		0.20
MPC		0.53
ClinPred		0.79	D
GERP RS		2.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.054

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: rs1893717804; hg19: chr15-45879709;