16-75647888-G-A

Variant names:

• chr16-75647888-G-A
• NM_018975.4:c.6G>A

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 2P and 7B. PM2 BP4_Strong BP6_Moderate BP7

The NM_018975.4(TERF2IP):​c.6G>A​(p.Ala2Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000689 in 1,452,054 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 Likely benign (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: TERF2IP NM_018975.4 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.126
• Publications: 0 publications found

Genes affected

TERF2IP (HGNC:19246): (TERF2 interacting protein) Enables G-rich strand telomeric DNA binding activity and phosphatase binding activity. Involved in several processes, including positive regulation of NIK/NF-kappaB signaling; regulation of nucleobase-containing compound metabolic process; and regulation of protein modification process. Located in chromosome, telomeric region; cytosol; and nuclear body. Part of shelterin complex. [provided by Alliance of Genome Resources, Apr 2022]

KARS1 (HGNC:6215): (lysyl-tRNA synthetase 1) Aminoacyl-tRNA synthetases are a class of enzymes that charge tRNAs with their cognate amino acids. Lysyl-tRNA synthetase is a homodimer localized to the cytoplasm which belongs to the class II family of tRNA synthetases. It has been shown to be a target of autoantibodies in the human autoimmune diseases, polymyositis or dermatomyositis. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

KARS1 Gene-Disease associations (from GenCC):

• autosomal recessive nonsyndromic hearing loss 89

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), G2P
• leukoencephalopathy, progressive, infantile-onset, with or without deafness

  Inheritance: AR Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• Charcot-Marie-Tooth disease recessive intermediate B

  Inheritance: AR, Unknown Classification: SUPPORTIVE, LIMITED Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
• hearing loss, autosomal recessive

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• nonsyndromic genetic hearing loss

  Inheritance: AR Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.51).
• BP6: Variant 16-75647888-G-A is Benign according to our data. Variant chr16-75647888-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 3227198.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=-0.126 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TERF2IP	NM_018975.4	c.6G>A	p.Ala2Ala	synonymous_variant	Exon 1 of 3	ENST00000300086.5	NP_061848.2
KARS1	NM_005548.3	c.-249C>T		upstream_gene_variant		ENST00000302445.8	NP_005539.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TERF2IP	ENST00000300086.5	c.6G>A	p.Ala2Ala	synonymous_variant	Exon 1 of 3	1	NM_018975.4	ENSP00000300086.4
KARS1	ENST00000302445.8	c.-249C>T		upstream_gene_variant		1	NM_005548.3	ENSP00000303043.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.89e-7 AC: 1 AN: 1452054 Hom.: 0 Cov.: 31 AF XY: 0.00000139 AC XY: 1 AN XY: 720600

⚠️ 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: 33220

American (AMR) AF: 0.00 AC: 0 AN: 44094

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25846

East Asian (EAS) AF: 0.00 AC: 0 AN: 39454

South Asian (SAS) AF: 0.00 AC: 0 AN: 85916

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53128

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5732

European-Non Finnish (NFE) AF: 9.05e-7 AC: 1 AN: 1104838

Other (OTH) AF: 0.00 AC: 0 AN: 59826

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Benign:1

Nov 22, 2023

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.51
CADD	Benign	11
DANN	Benign	0.80
PhyloP100		-0.13
PromoterAI		-0.28	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.8

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

hg19: chr16-75681786;