chr2-151485703-G-A

Position:

• chr2-151485703-G-A

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BS1_Supporting

The NM_001164507.2(NEB):​c.*57C>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000203 in 1,525,160 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0010 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00011 (1 hom.)
• Consequence: NEB NM_001164507.2 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0430

Genes affected

NEB (HGNC:7720): (nebulin) This gene encodes nebulin, a giant protein component of the cytoskeletal matrix that coexists with the thick and thin filaments within the sarcomeres of skeletal muscle. In most vertebrates, nebulin accounts for 3 to 4% of the total myofibrillar protein. The encoded protein contains approximately 30-amino acid long modules that can be classified into 7 types and other repeated modules. Protein isoform sizes vary from 600 to 800 kD due to alternative splicing that is tissue-, species-,and developmental stage-specific. Of the 183 exons in the nebulin gene, at least 43 are alternatively spliced, although exons 143 and 144 are not found in the same transcript. Of the several thousand transcript variants predicted for nebulin, the RefSeq Project has decided to create three representative RefSeq records. Mutations in this gene are associated with recessive nemaline myopathy. [provided by RefSeq, Sep 2009]

RIF1 (HGNC:23207): (replication timing regulatory factor 1) This gene encodes a protein that shares homology with the yeast teleomere binding protein, Rap1 interacting factor 1. This protein localizes to aberrant telomeres may be involved in DNA repair. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Apr 2010]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.85).
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.000998 (152/152298) while in subpopulation AFR AF= 0.0033 (137/41556). AF 95% confidence interval is 0.00285. There are 0 homozygotes in gnomad4. There are 67 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NEB	NM_001164507.2	c.*57C>T		3_prime_UTR_variant	182/182	ENST00000427231.7	NP_001157979.2
NEB	NM_001164508.2	c.*57C>T		3_prime_UTR_variant	182/182	ENST00000397345.8	NP_001157980.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NEB	ENST00000397345.8	c.*57C>T		3_prime_UTR_variant	182/182	5	NM_001164508.2	ENSP00000380505	P5
NEB	ENST00000427231.7	c.*57C>T		3_prime_UTR_variant	182/182	5	NM_001164507.2	ENSP00000416578	A2

Frequencies

GnomAD3 genomes AF: 0.000999 AC: 152 AN: 152180 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00331

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000654

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: 0.0000441

Gnomad OTH AF: 0.000956

GnomAD4 exome AF: 0.000114 AC: 157 AN: 1372862 Hom.: 1 Cov.: 24 AF XY: 0.0000859 AC XY: 58 AN XY: 674898

Gnomad4 AFR exome AF: 0.00332

Gnomad4 AMR exome AF: 0.000342

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000258

Gnomad4 SAS exome AF: 0.0000138

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000208

Gnomad4 OTH exome AF: 0.000247

GnomAD4 genome AF: 0.000998 AC: 152 AN: 152298 Hom.: 0 Cov.: 32 AF XY: 0.000900 AC XY: 67 AN XY: 74478

Gnomad4 AFR AF: 0.00330

Gnomad4 AMR AF: 0.000653

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.000946

Alfa AF: 0.000854 Hom.: 0

Bravo AF: 0.00134

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Nemaline myopathy 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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	-0.85
CADD	Benign	7.0
DANN	Benign	0.60

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: rs566096042; hg19: chr2-152342217;