2-96254006-G-T

Position:

• chr2-96254006-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_017849.4(TMEM127):​c.519C>A​(p.Phe173Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,894 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. F173C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: TMEM127 NM_017849.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: -0.0300

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 14 uncertain in NM_017849.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.917

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TMEM127	NM_017849.4	c.519C>A	p.Phe173Leu	missense_variant	4/4	ENST00000258439.8
TMEM127	NM_001193304.3	c.519C>A	p.Phe173Leu	missense_variant	4/4
TMEM127	NM_001407282.1	c.267C>A	p.Phe89Leu	missense_variant	3/3
TMEM127	NM_001407283.1	c.267C>A	p.Phe89Leu	missense_variant	3/3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TMEM127	ENST00000258439.8	c.519C>A	p.Phe173Leu	missense_variant	4/4	1	NM_017849.4	P1
TMEM127	ENST00000432959.1	c.519C>A	p.Phe173Leu	missense_variant	4/4	1		P1
TMEM127	ENST00000435268.1	c.267C>A	p.Phe89Leu	missense_variant	3/3	3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461894 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727248

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: 0.0000348

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Pheochromocytoma Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Mar 06, 2024

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 12, 2022

The p.F173L variant (also known as c.519C>A), located in coding exon 3 of the TMEM127 gene, results from a C to A substitution at nucleotide position 519. The phenylalanine at codon 173 is replaced by leucine, an amino acid with highly similar 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. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Hereditary pheochromocytoma-paraganglioma Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 03, 2024

This sequence change replaces phenylalanine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 173 of the TMEM127 protein (p.Phe173Leu). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TMEM127-related conditions. ClinVar contains an entry for this variant (Variation ID: 463851). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.33
CADD	Benign	20
DANN	Uncertain	0.99
DEOGEN2	Benign	0.28	T;T;.
Eigen	Benign	-0.29
Eigen_PC	Benign	-0.35
FATHMM_MKL	Uncertain	0.83	D
M_CAP	Pathogenic	0.36	D
MetaRNN	Pathogenic	0.92	D;D;D
MetaSVM	Pathogenic	0.81	D
MutationAssessor	Benign	0.90	L;L;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-5.0	D;D;D
REVEL	Pathogenic	0.78
Sift	Uncertain	0.0070	D;D;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		0.99	D;D;.
Vest4		0.91
MutPred		0.71		Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);.;
MVP		0.71
MPC		1.3
ClinPred		0.99	D
GERP RS		-1.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.56
gMVP		0.92

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: rs758676810; hg19: chr2-96919744;