NM_000355.4:c.-67C>T

Variant names:

• chr22-30607265-C-T
• rs1432247695
• NM_000355.4:c.-67C>T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_000355.4(TCN2):​c.-67C>T variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000953 in 1,573,434 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000091 (0 hom.)
• Consequence: TCN2 NM_000355.4 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.135

Genes affected

TCN2 (HGNC:11653): (transcobalamin 2) This gene encodes a member of the vitamin B12-binding protein family. This family of proteins, alternatively referred to as R binders, is expressed in various tissues and secretions. This plasma protein binds cobalamin and mediates the transport of cobalamin into cells. This protein and other mammalian cobalamin-binding proteins, such as transcobalamin I and gastric intrisic factor, may have evolved by duplication of a common ancestral gene. Alternative splicing results in multiple transcript variants.[provided by RefSeq, May 2010]

PES1 (HGNC:8848): (pescadillo ribosomal biogenesis factor 1) This gene encodes a nuclear protein that contains a breast cancer associated gene 1 (BRCA1) C-terminal interaction domain. The encoded protein interacts with BOP1 and WDR12 to form the PeBoW complex, which plays a critical role in cell proliferation via pre-rRNA processing and 60S ribosomal subunit maturation. Expression of this gene may play an important role in breast cancer proliferation and tumorigenicity. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. Pseudogenes of this gene are located on the long arm of chromosome 4 and the short arm of chromosome 9. [provided by RefSeq, Aug 2011]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TCN2	NM_000355.4	c.-67C>T		5_prime_UTR_variant	Exon 1 of 9	ENST00000215838.8	NP_000346.2
TCN2	NM_001184726.2	c.-67C>T		5_prime_UTR_variant	Exon 1 of 9		NP_001171655.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TCN2	ENST00000215838	c.-67C>T		5_prime_UTR_variant	Exon 1 of 9	1	NM_000355.4	ENSP00000215838.3

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152094 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000915 AC: 13 AN: 1421340 Hom.: 0 Cov.: 27 AF XY: 0.00000846 AC XY: 6 AN XY: 709502

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000121

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152094 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74292

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Transcobalamin II deficiency Uncertain:1

Jan 15, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
CADD	Benign	7.1
DANN	Benign	0.75

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: rs1432247695; hg19: chr22-31003252;