17-79778326-GC-GCCC

Variant names:

• chr17-79778326-G-GCC
• rs781870900
• NM_005189.3:c.72+24_72+25dupCC

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_005189.3(CBX2):​c.72+24_72+25dupCC variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000708 in 1,411,456 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.1e-7 (0 hom.)
• Consequence: CBX2 NM_005189.3 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.584
• Publications: 0 publications found

Genes affected

CBX2 (HGNC:1552): (chromobox 2) This gene encodes a component of the polycomb multiprotein complex, which is required to maintain the transcriptionally repressive state of many genes throughout development via chromatin remodeling and modification of histones. Disruption of this gene in mice results in male-to-female gonadal sex reversal. Mutations in this gene are also associated with gonadal dysgenesis in humans. Alternatively spliced transcript variants encoding different isoforms have been noted for this gene.[provided by RefSeq, Mar 2010]

CBX2 Gene-Disease associations (from GenCC):

• 46,XY complete gonadal dysgenesis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• 46,XY sex reversal 5

  Inheritance: AR, SD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics

ENSG00000295072 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005189.3. 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
	CBX2	NM_005189.3	MANE Select	c.72+24_72+25dupCC		intron	N/A	NP_005180.1	Q14781-1
	CBX2	NM_032647.4		c.72+24_72+25dupCC		intron	N/A	NP_116036.1	Q14781-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CBX2	ENST00000310942.9	TSL:1 MANE Select	c.72+19_72+20insCC		intron	N/A	ENSP00000308750.4	Q14781-1
	CBX2	ENST00000269399.5	TSL:1	c.72+19_72+20insCC		intron	N/A	ENSP00000269399.5	Q14781-2
	CBX2	ENST00000571484.1	TSL:1	n.145+19_145+20insCC		intron	N/A

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 7.08e-7 AC: 1 AN: 1411456 Hom.: 0 Cov.: 30 AF XY: 0.00000143 AC XY: 1 AN XY: 700478

⚠️ 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: 31662

American (AMR) AF: 0.00 AC: 0 AN: 40798

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25088

East Asian (EAS) AF: 0.00 AC: 0 AN: 37582

South Asian (SAS) AF: 0.00 AC: 0 AN: 81518

European-Finnish (FIN) AF: 0.0000250 AC: 1 AN: 40026

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4720

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1091668

Other (OTH) AF: 0.00 AC: 0 AN: 58394

⚠️ 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
PhyloP100		-0.58

Splicing

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

Other links and lift over

dbSNP: rs781870900; hg19: chr17-77752125;