chr12-98515937-A-C

Variant names:

• chr12-98515937-A-C
• rs727505279
• NM_001032283.3:c.70A>C

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PP3 BS2

The NM_001032283.3(TMPO):​c.70A>C​(p.Asn24His) variant causes a missense change. The variant allele was found at a frequency of 0.00000684 in 1,461,368 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N24K) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: TMPO NM_001032283.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 6.20
• Publications: 0 publications found

Genes affected

TMPO (HGNC:11875): (thymopoietin) Through alternative splicing, this gene encodes several distinct LEM domain containing protein isoforms. LEM domain proteins include inner nuclear membrane and intranuclear proteins, and are involved in a variety of cellular functions including gene expression, chromatin organization, and replication and cell cycle control. The encoded alpha isoform is broadly diffuse in the nucleus and contains a lamin binding domain, while the beta and gamma isoforms are localized to the nuclear membrane and contain an HDAC3 interaction domain. The distinct isoforms may compete with each other when acting to chaperone other proteins and regulate transcription. [provided by RefSeq, Aug 2019]

TMPO-AS1 (HGNC:44158): (TMPO antisense RNA 1)

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.755
• BS2: High AC in GnomAdExome4 at 10 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TMPO	NM_001032283.3	c.70A>C	p.Asn24His	missense_variant	Exon 1 of 9	ENST00000556029.6	NP_001027454.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TMPO	ENST00000556029.6	c.70A>C	p.Asn24His	missense_variant	Exon 1 of 9	1	NM_001032283.3	ENSP00000450627.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000160 AC: 4 AN: 249376 AF XY: 0.0000148

Gnomad AFR exome AF: 0.000248

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461368 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727014

African (AFR) AF: 0.000239 AC: 8 AN: 33472

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26118

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53126

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111844

Other (OTH) AF: 0.0000331 AC: 2 AN: 60372

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000151

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:2

Sep 24, 2014

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Asn24His variant in TMPO has not been previously reported in individuals wit h cardiomyopathy or in large population studies. Computational prediction tools and conservation analysis do not provide strong support for or against an impact to the protein. In summary, the clinical significance of the Asn24His variant i s uncertain. -

Apr 14, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.N24H variant (also known as c.70A>C), located in coding exon 1 of the TMPO gene, results from an A to C substitution at nucleotide position 70. The asparagine at codon 24 is replaced by histidine, an amino acid with similar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Loeys-Dietz syndrome 2 Uncertain:1

Oct 15, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces asparagine, which is neutral and polar, with histidine, which is basic and polar, at codon 24 of the TMPO protein (p.Asn24His). This variant is present in population databases (rs727505279, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with TMPO-related conditions. ClinVar contains an entry for this variant (Variation ID: 180005). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not provided Uncertain:1

May 10, 2019

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge; Reported in ClinVar but additional evidence is not available (ClinVar Variant ID# 180005; Landrum et al., 2016) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.21
BayesDel_addAF	Benign	-0.12	T
BayesDel_noAF	Benign	-0.11
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Benign	0.21	T;T;D;.;.
Eigen	Pathogenic	0.69
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.91	D;D;D;D;D
M_CAP	Pathogenic	0.81	D
MetaRNN	Pathogenic	0.75	D;D;D;D;D
MetaSVM	Uncertain	0.26	D
MutationAssessor	Uncertain	2.1	.;.;M;.;.
PhyloP100		6.2
PrimateAI	Pathogenic	0.86	D
PROVEAN	Uncertain	-3.6	D;D;D;D;D
REVEL	Uncertain	0.55
Sift	Uncertain	0.0040	D;D;D;D;D
Sift4G	Uncertain	0.0040	D;D;D;D;D
Polyphen		1.0	D;.;D;.;.
Vest4		0.59
MutPred		0.66		Gain of catalytic residue at N24 (P = 0);Gain of catalytic residue at N24 (P = 0);Gain of catalytic residue at N24 (P = 0);Gain of catalytic residue at N24 (P = 0);Gain of catalytic residue at N24 (P = 0);
MVP		0.89
MPC		0.41
ClinPred		0.92	D
GERP RS		4.7
PromoterAI		-0.023	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Varity_R		0.67
gMVP		0.26
Mutation Taster		=49/51	disease causing

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: rs727505279; hg19: chr12-98909715;