rs386833856

Variant names:

• chr2-218661308-G-A
• rs386833856
• NM_001079866.2:c.320+1G>A

Your query was ambiguous. Multiple possible variants found:

• chr2-218661308-G-A
• chr2-218661308-G-C
• chr2-218661308-G-T

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The ENST00000359273.8(BCS1L):​c.320+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,878 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. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BCS1L ENST00000359273.8 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.98
• Publications: 0 publications found

Genes affected

BCS1L (HGNC:1020): (BCS1 homolog, ubiquinol-cytochrome c reductase complex chaperone) This gene encodes a homolog of the S. cerevisiae bcs1 protein which is involved in the assembly of complex III of the mitochondrial respiratory chain. The encoded protein does not contain a mitochondrial targeting sequence but experimental studies confirm that it is imported into mitochondria. Mutations in this gene are associated with mitochondrial complex III deficiency and the GRACILE syndrome. Several alternatively spliced transcripts encoding two different isoforms have been described. [provided by RefSeq, Jan 2016]

BCS1L Gene-Disease associations (from GenCC):

• Bjornstad syndrome

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Orphanet, Ambry Genetics, ClinGen, G2P
• GRACILE syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P
• Leigh syndrome

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: PanelApp Australia, ClinGen
• mitochondrial complex III deficiency nuclear type 1

  Inheritance: AR Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• mitochondrial complex III deficiency

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• renal tubulopathy-encephalopathy-liver failure syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.29285714 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.9, offset of 5, new splice context is: aagGTgggg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-218661308-G-A is Pathogenic according to our data. Variant chr2-218661308-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 1458352.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000359273.8. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BCS1L	NM_001079866.2	MANE Select	c.320+1G>A		splice_donor intron	N/A	NP_001073335.1
	BCS1L	NM_001257342.2		c.320+1G>A		splice_donor intron	N/A	NP_001244271.1
	BCS1L	NM_001257343.2		c.320+1G>A		splice_donor intron	N/A	NP_001244272.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BCS1L	ENST00000359273.8	TSL:1 MANE Select	c.320+1G>A		splice_donor intron	N/A	ENSP00000352219.3
	BCS1L	ENST00000392109.5	TSL:1	c.320+1G>A		splice_donor intron	N/A	ENSP00000375957.1
	BCS1L	ENST00000392111.7	TSL:1	c.320+1G>A		splice_donor intron	N/A	ENSP00000375959.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461878 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727238

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112004

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Uncertain	0.11
CADD	Pathogenic	35
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Uncertain	0.96	D
PhyloP100		10
GERP RS		4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.95		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.62		Position offset: 4
DS_DL_spliceai		0.95		Position offset: -1

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

Other links and lift over

dbSNP: rs386833856; hg19: chr2-219526031;