5-55231450-T-G

Variant names:

• chr5-55231450-T-G
• rs1554019818
• NM_021147.5:c.978A>C

Variant summary

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

The NM_021147.5(CCNO):​c.978A>C​(p.Ile326Ile) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,836 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.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CCNO NM_021147.5 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.0710
• Publications: 0 publications found

Genes affected

CCNO (HGNC:18576): (cyclin O) This gene encodes a member of the cyclin protein family, and the encoded protein is involved in regulation of the cell cycle. Disruption of this gene is associated with primary ciliary dyskinesia-19. Alternative splicing results in multiple transcript variants. This gene, which has a previous symbol of UNG2, was erroneously identified as a uracil DNA glycosylase in PubMed ID: 2001396. A later publication, PubMed ID: 8419333, identified this gene's product as a cyclin protein family member. The UNG2 symbol is also used as a specific protein isoform name for the UNG gene (GeneID 7374), so confusion exists in the scientific literature and in some databases for these two genes. [provided by RefSeq, Jul 2014]

CCNO Gene-Disease associations (from GenCC):

• primary ciliary dyskinesia 29

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: G2P, Labcorp Genetics (formerly Invitae), PanelApp Australia, ClinGen, Ambry Genetics
• primary ciliary dyskinesia

  Inheritance: AD 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=-0.53).
• BP7: Synonymous conserved (PhyloP=-0.071 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CCNO	NM_021147.5	c.978A>C	p.Ile326Ile	synonymous_variant	Exon 3 of 3	ENST00000282572.5	NP_066970.3
CCNO	NR_125346.2	n.1439A>C		non_coding_transcript_exon_variant	Exon 3 of 3
CCNO	NR_125347.2	n.1068A>C		non_coding_transcript_exon_variant	Exon 3 of 3
CCNO	NR_125348.1	n.1042A>C		non_coding_transcript_exon_variant	Exon 2 of 2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CCNO	ENST00000282572.5	c.978A>C	p.Ile326Ile	synonymous_variant	Exon 3 of 3	1	NM_021147.5	ENSP00000282572.4
CCNO	ENST00000501463.2	n.*958A>C		non_coding_transcript_exon_variant	Exon 3 of 3	1		ENSP00000422485.1
CCNO	ENST00000501463.2	n.*958A>C		3_prime_UTR_variant	Exon 3 of 3	1		ENSP00000422485.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461836 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727228

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: 53364

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112010

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.53
CADD	Benign	7.4
DANN	Benign	0.71
PhyloP100		-0.071

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

Other links and lift over

dbSNP: rs1554019818; hg19: chr5-54527278;