9-133352134-C-CT

Position:

• chr9-133352134-C-CT

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_003172.4(SURF1):​c.759_760insA​(p.Val254SerfsTer38) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. T253T) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: SURF1 NM_003172.4 frameshift
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: -0.691

Genes affected

SURF1 (HGNC:11474): (SURF1 cytochrome c oxidase assembly factor) This gene encodes a protein localized to the inner mitochondrial membrane and thought to be involved in the biogenesis of the cytochrome c oxidase complex. The protein is a member of the SURF1 family, which includes the related yeast protein SHY1 and rickettsial protein RP733. The gene is located in the surfeit gene cluster, a group of very tightly linked genes that do not share sequence similarity, where it shares a bidirectional promoter with SURF2 on the opposite strand. Defects in this gene are a cause of Leigh syndrome, a severe neurological disorder that is commonly associated with systemic cytochrome c oxidase deficiency. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 34 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 9-133352134-C-CT is Pathogenic according to our data. Variant chr9-133352134-C-CT is described in ClinVar as [Likely_pathogenic]. Clinvar id is 456666.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SURF1	NM_003172.4	c.759_760insA	p.Val254SerfsTer38	frameshift_variant	8/9	ENST00000371974.8
SURF1	NM_001280787.1	c.432_433insA	p.Val145SerfsTer38	frameshift_variant	7/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SURF1	ENST00000371974.8	c.759_760insA	p.Val254SerfsTer38	frameshift_variant	8/9	1	NM_003172.4	P1
SURF1	ENST00000615505.4	c.432_433insA	p.Val145SerfsTer38	frameshift_variant	7/8	1
SURF1	ENST00000437995.1	n.669_670insA		non_coding_transcript_exon_variant	7/8	5
SURF1	ENST00000495952.5	n.749_750insA		non_coding_transcript_exon_variant	4/5	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Leigh syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 14, 2021

- -

Computational scores

Source: dbNSFP v4.3

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: rs1554768246; hg19: chr9-136218989;