6-8026427-T-C

Variant names:

• chr6-8026427-T-C
• rs764780126
• NM_201280.3:c.326-2A>G

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_201280.3(BLOC1S5):​c.326-2A>G variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.000000685 in 1,460,624 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BLOC1S5 NM_201280.3 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 4.67
• Publications: 0 publications found

Genes affected

BLOC1S5 (HGNC:18561): (biogenesis of lysosomal organelles complex 1 subunit 5) This gene encodes a component of BLOC-1 (biogenesis of lysosome-related organelles complex 1). Components of this complex are involved in the biogenesis of organelles such as melanosomes and platelet-dense granules. A mouse model for Hermansky-Pudlak Syndrome is mutated in the murine version of this gene. Alternative splicing results in multiple transcript variants. Read-through transcription exists between this gene and the upstream EEF1E1 (eukaryotic translation elongation factor 1 epsilon 1) gene, as well as with the downstream TXNDC5 (thioredoxin domain containing 5) gene. [provided by RefSeq, Dec 2010]

EEF1E1-BLOC1S5 (HGNC:49187): (EEF1E1-BLOC1S5 readthrough (NMD candidate)) This locus represents naturally occurring read-through transcription between the neighboring EEF1E1 (eukaryotic translation elongation factor 1 epsilon 1) and MUTED (muted homolog) genes on chromosome 6. The read-through transcript is a candidate for nonsense-mediated mRNA decay (NMD) and is unlikely to produce a protein product. [provided by RefSeq, Dec 2010]

BLOC1S5-TXNDC5 (HGNC:42001): (BLOC1S5-TXNDC5 readthrough (NMD candidate)) This locus represents naturally occurring read-through transcription between the neighboring MUTED (muted homolog) and TXNDC5 (thioredoxin domain containing 5) genes on chromosome 6. The read-through transcript is a candidate for nonsense-mediated mRNA decay (NMD) and is unlikely to produce a protein product. [provided by RefSeq, Dec 2010]

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_201280.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BLOC1S5	NM_201280.3	MANE Select	c.326-2A>G		splice_acceptor intron	N/A	NP_958437.1	Q8TDH9-1
	BLOC1S5	NM_001199322.1		c.134-2A>G		splice_acceptor intron	N/A	NP_001186251.1	Q8TDH9-3
	BLOC1S5	NM_001199323.1		c.196-2A>G		splice_acceptor intron	N/A	NP_001186252.1	A0A0A0MTN6

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BLOC1S5	ENST00000397457.7	TSL:1 MANE Select	c.326-2A>G		splice_acceptor intron	N/A	ENSP00000380598.2	Q8TDH9-1
	BLOC1S5	ENST00000244777.6	TSL:1	n.*174-2A>G		splice_acceptor intron	N/A	ENSP00000244777.2	G5E931
	EEF1E1-BLOC1S5	ENST00000397456.2	TSL:3	n.*142-2A>G		splice_acceptor intron	N/A	ENSP00000380597.2	C9J1V9

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460624 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726694

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33446

American (AMR) AF: 0.00 AC: 0 AN: 44674

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26126

East Asian (EAS) AF: 0.00 AC: 0 AN: 39656

South Asian (SAS) AF: 0.00 AC: 0 AN: 86140

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53026

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111412

Other (OTH) AF: 0.00 AC: 0 AN: 60378

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.33	D
BayesDel_noAF	Pathogenic	0.24
CADD	Pathogenic	30
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Uncertain	0.96	D
PhyloP100		4.7
GERP RS		5.3
Mutation Taster		=2/98	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.98		Position offset: -2

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

Other links and lift over

dbSNP: rs764780126; hg19: chr6-8026660; COSMIC: COSV99789349;