rs121908826

Variant names:

• chr2-96254117-T-C
• rs121908826
• NM_017849.4:c.410-2A>G

Your query was ambiguous. Multiple possible variants found:

• chr2-96254117-T-C
• chr2-96254117-T-G

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_017849.4(TMEM127):​c.410-2A>G variant causes a splice acceptor, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TMEM127 NM_017849.4 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 2.94
• Publications: 1 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease,
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-96254117-T-C is Pathogenic according to our data. Variant chr2-96254117-T-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 449954.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TMEM127	NM_017849.4	c.410-2A>G		splice_acceptor_variant, intron_variant	Intron 3 of 3	ENST00000258439.8	NP_060319.1
TMEM127	NM_001193304.3	c.410-2A>G		splice_acceptor_variant, intron_variant	Intron 3 of 3		NP_001180233.1
TMEM127	NM_001407282.1	c.158-2A>G		splice_acceptor_variant, intron_variant	Intron 2 of 2		NP_001394211.1
TMEM127	NM_001407283.1	c.158-2A>G		splice_acceptor_variant, intron_variant	Intron 2 of 2		NP_001394212.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TMEM127	ENST00000258439.8	c.410-2A>G		splice_acceptor_variant, intron_variant	Intron 3 of 3	1	NM_017849.4	ENSP00000258439.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:3

-

Genome Diagnostics Laboratory, University Medical Center Utrecht

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

May 01, 2017

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is denoted TMEM127 c.410-2A>G or IVS3-2A>G and consists of an A>G nucleotidesubstitution at the -2 position of intron 3 of the TMEM127 gene. This variant destroys a canonical splice acceptor siteand is predicted to cause abnormal gene splicing, leading to either an abnormal message that is subject to nonsense-mediated mRNA decay or to an abnormal protein product. This variant has not, to our knowledge, been published inthe literature. Based on the current evidence, we consider this variant to be pathogenic. -

-

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Pathogenic:1

Dec 12, 2018

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.410-2A>G intronic pathogenic mutation results from an A to G substitution two nucleotides upstream from coding exon 3 in the TMEM127 gene. This mutation has been reported in a homozygous state in an individual diagnosed with bilateral pheochromocytoma at age 31 as well as dysmorphic features and intellectual disability (Eijkelenkamp K et al. Clin. Genet., 2018 May;93:1049-1056). This nucleotide position is highly conserved in available vertebrate species. Using the BDGP and ESEfinder splice site prediction tools, this alteration is predicted to abolish the native splice acceptor site; however, direct evidence is unavailable. Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as likely pathogenic. -

Hereditary pheochromocytoma-paraganglioma Pathogenic:1

Feb 27, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. A different variant affecting this nucleotide (c.410-2A>C, also known as IVS3-2A>C) has been determined to be pathogenic (PMID: 25389632, 20154675, 21156949). This suggests that this nucleotide is important for normal RNA splicing, and that other variants at this position may also be pathogenic. Nucleotide substitutions within the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. This variant has been observed as homozygous in an individual affected with bilateral pheochromocytoma (PMID: 29282712). ClinVar contains an entry for this variant (Variation ID: 449954). This variant is not present in population databases (ExAC no frequency). This sequence change affects an acceptor splice site in the last intron (intron 3) of the TMEM127 gene. While this is not anticipated to result in nonsense mediated decay, it likely alters RNA splicing and results in a disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.20
CADD	Pathogenic	35
DANN	Uncertain	0.99
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		2.9
GERP RS		6.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.93		Position offset: -10
DS_AL_spliceai		1.0		Position offset: -2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs121908826; hg19: chr2-96919855;