2-218660344-A-T

Variant names:

• chr2-218660344-A-T
• rs77487601
• NM_001079866.2:c.-49-595A>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001320717.2(BCS1L):​c.-127A>T variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BCS1L NM_001320717.2 5_prime_UTR_premature_start_codon_gain
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.594
• 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: Orphanet, ClinGen, PanelApp Australia, Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• GRACILE syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae)
• 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: Labcorp Genetics (formerly Invitae), Ambry Genetics
• 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_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.8).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001320717.2. 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
	BCS1L	NM_001079866.2	MANE Select	c.-49-595A>T		intron	N/A	NP_001073335.1	Q9Y276
	BCS1L	NM_001320717.2		c.-127A>T		5_prime_UTR_premature_start_codon_gain	Exon 2 of 9	NP_001307646.1	Q9Y276
	BCS1L	NM_001371443.1		c.-127A>T		5_prime_UTR_premature_start_codon_gain	Exon 2 of 9	NP_001358372.1	Q9Y276

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BCS1L	ENST00000359273.8	TSL:1 MANE Select	c.-49-595A>T		intron	N/A	ENSP00000352219.3	Q9Y276
	BCS1L	ENST00000392109.5	TSL:1	c.-50+126A>T		intron	N/A	ENSP00000375957.1	Q9Y276
	BCS1L	ENST00000392111.7	TSL:1	c.-50+99A>T		intron	N/A	ENSP00000375959.2	Q9Y276

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 0

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.80
CADD	Benign	6.8
DANN	Benign	0.72
PhyloP100		0.59
PromoterAI		-0.0038	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs77487601; hg19: chr2-219525067;