NM_017849.4:c.419G>T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PM5PP3_Moderate

The NM_017849.4(TMEM127):​c.419G>T​(p.Cys140Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,854 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. C140R) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

TMEM127
NM_017849.4 missense

Scores

11
5
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 7.41

Publications

3 publications found
Variant links:
Genes affected
TMEM127 (HGNC:26038): (transmembrane protein 127) This gene encodes a transmembrane protein with four predicted transmembrane domains. The protein is associated with a subpopulation of vesicular organelles corresponding to early endosomal structures, with the Golgi, and with lysosomes, and may participate in protein trafficking between these structures. Mutations in this gene and several other genes cause pheochromocytomas. Alternatively spliced transcript variants encoding the same protein have been identified. [provided by RefSeq, Aug 2022]
TMEM127 Gene-Disease associations (from GenCC):
  • hereditary pheochromocytoma-paraganglioma
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • pheochromocytoma
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
  • renal cell carcinoma
    Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr2-96254107-A-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 126970.Status of the report is no_assertion_criteria_provided, 0 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.923

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TMEM127NM_017849.4 linkc.419G>T p.Cys140Phe missense_variant Exon 4 of 4 ENST00000258439.8 NP_060319.1
TMEM127NM_001193304.3 linkc.419G>T p.Cys140Phe missense_variant Exon 4 of 4 NP_001180233.1
TMEM127NM_001407282.1 linkc.167G>T p.Cys56Phe missense_variant Exon 3 of 3 NP_001394211.1
TMEM127NM_001407283.1 linkc.167G>T p.Cys56Phe missense_variant Exon 3 of 3 NP_001394212.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TMEM127ENST00000258439.8 linkc.419G>T p.Cys140Phe missense_variant Exon 4 of 4 1 NM_017849.4 ENSP00000258439.3

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152176
Hom.:
0
Cov.:
32
show subpopulations
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461678
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727158
show subpopulations
⚠️ 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:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53218
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1112006
Other (OTH)
AF:
0.00
AC:
0
AN:
60392
⚠️ 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.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152176
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74328
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41442
American (AMR)
AF:
0.00
AC:
0
AN:
15260
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68044
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1
Jul 02, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.C140F variant (also known as c.419G>T), located in coding exon 3 of the TMEM127 gene, results from a G to T substitution at nucleotide position 419. The cysteine at codon 140 is replaced by phenylalanine, an amino acid with highly dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear.

Hereditary pheochromocytoma-paraganglioma Uncertain:1
Sep 02, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This sequence change replaces cysteine with phenylalanine at codon 140 of the TMEM127 protein (p.Cys140Phe). The cysteine residue is highly conserved and there is a large physicochemical difference between cysteine and phenylalanine. This variant is not present in population databases (ExAC no frequency). This particular variant has not been reported in the literature in individuals with TMEM127-related disease, but two different changes affecting the same codon (p.Cys140Tyr and p.Cys140Arg) have been reported in individuals affected with pheochromocytoma (PMID: 26960314, 21156949, 22517554).

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Pathogenic
0.41
D
BayesDel_noAF
Pathogenic
0.35
CADD
Pathogenic
30
DANN
Uncertain
0.99
DEOGEN2
Benign
0.31
T;T;.
Eigen
Pathogenic
0.73
Eigen_PC
Pathogenic
0.76
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Benign
0.0
.;D;D
M_CAP
Uncertain
0.13
D
MetaRNN
Pathogenic
0.92
D;D;D
MetaSVM
Uncertain
0.28
D
MutationAssessor
Uncertain
2.0
M;M;.
PhyloP100
7.4
PrimateAI
Pathogenic
0.93
D
PROVEAN
Pathogenic
-7.3
D;D;D
REVEL
Pathogenic
0.86
Sift
Uncertain
0.0040
D;D;D
Sift4G
Pathogenic
0.0
D;D;D
Vest4
0.88
ClinPred
0.99
D
GERP RS
5.9
Varity_R
0.86
gMVP
0.96
Mutation Taster
=10/90
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

Publications

Other links and lift over

dbSNP: rs121908828; hg19: chr2-96919844; API