8-144095895-G-A

Variant names:

• chr8-144095895-G-A
• rs1278757401
• NM_001916.5:c.192G>A

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_001916.5(CYC1):​c.192G>A​(p.Leu64Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000686 in 1,457,310 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. L64L) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: CYC1 NM_001916.5 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.44
• Publications: 0 publications found

Genes affected

CYC1 (HGNC:2579): (cytochrome c1) This gene encodes a subunit of the cytochrome bc1 complex, which plays an important role in the mitochondrial respiratory chain by transferring electrons from the Rieske iron-sulfur protein to cytochrome c. Mutations in this gene may cause mitochondrial complex III deficiency, nuclear type 6. [provided by RefSeq, Dec 2013]

CYC1 Gene-Disease associations (from GenCC):

• mitochondrial complex III deficiency nuclear type 6

  Inheritance: AR, Unknown Classification: DEFINITIVE, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• mitochondrial disease

  Inheritance: AR Classification: MODERATE Submitted by: ClinGen
• mitochondrial complex III deficiency

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.61).
• BP7: Synonymous conserved (PhyloP=1.44 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001916.5. 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
	CYC1	NM_001916.5	MANE Select	c.192G>A	p.Leu64Leu	synonymous	Exon 2 of 7	NP_001907.3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CYC1	ENST00000318911.5	TSL:1 MANE Select	c.192G>A	p.Leu64Leu	synonymous	Exon 2 of 7	ENSP00000317159.4	P08574
	CYC1	ENST00000533444.1	TSL:1	n.857G>A		non_coding_transcript_exon	Exon 1 of 6
	CYC1	ENST00000876792.1		c.270G>A	p.Leu90Leu	synonymous	Exon 3 of 8	ENSP00000546851.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1457310 Hom.: 0 Cov.: 29 AF XY: 0.00000138 AC XY: 1 AN XY: 725164

⚠️ 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: 33466

American (AMR) AF: 0.00 AC: 0 AN: 44640

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26098

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86242

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49178

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5758

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111876

Other (OTH) AF: 0.00 AC: 0 AN: 60354

⚠️ 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_noAF	Benign	-0.61
CADD	Benign	11
DANN	Benign	0.92
PhyloP100		1.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1278757401; hg19: chr8-145150798;