NM_004637.6:c.471G>T

Variant names:

• chr3-128807614-G-T
• rs121909081
• NM_004637.6:c.471G>T

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PS1 PM1 PM2 PP3_Strong PP5_Moderate

The NM_004637.6(RAB7A):​c.471G>T​(p.Lys157Asn) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in Lovd.

• Frequency: Genomes: not found (cov: 32)
• Consequence: RAB7A NM_004637.6 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.17

Genes affected

RAB7A (HGNC:9788): (RAB7A, member RAS oncogene family) RAB family members are small, RAS-related GTP-binding proteins that are important regulators of vesicular transport. Each RAB protein targets multiple proteins that act in exocytic / endocytic pathways. This gene encodes a RAB family member that regulates vesicle traffic in the late endosomes and also from late endosomes to lysosomes. This encoded protein is also involved in the cellular vacuolation of the VacA cytotoxin of Helicobacter pylori. Mutations at highly conserved amino acid residues in this gene have caused some forms of Charcot-Marie-Tooth (CMT) type 2 neuropathies. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PS1: Transcript NM_004637.6 (RAB7A) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in Lovd
• PM1: In a chain Ras-related protein Rab-7a (size 205) in uniprot entity RAB7A_HUMAN there are 10 pathogenic changes around while only 1 benign (91%) in NM_004637.6
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.961
• PP5: Variant 3-128807614-G-T is Pathogenic according to our data. Variant chr3-128807614-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 846631.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr3-128807614-G-T is described in UniProt as null. Variant chr3-128807614-G-T is described in UniProt as null. Variant chr3-128807614-G-T is described in UniProt as null. Variant chr3-128807614-G-T is described in UniProt as null.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RAB7A	NM_004637.6	c.471G>T	p.Lys157Asn	missense_variant	Exon 5 of 6	ENST00000265062.8	NP_004628.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RAB7A	ENST00000265062.8	c.471G>T	p.Lys157Asn	missense_variant	Exon 5 of 6	1	NM_004637.6	ENSP00000265062.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth disease type 2B Pathogenic:1

Jan 20, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. A different variant (c.471G>C) giving rise to the same protein effect observed here (p.Lys157Asn) has been determined to be pathogenic (PMID: 17060578). This suggests that this variant is also likely to be causative of disease. This missense change has been reported to affect RAB7A protein function (PMID: 18501189, 21151572, 23179371, 23188822, 23458836, 24344282). This variant has not been reported in the literature in individuals with RAB7A-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces lysine with asparagine at codon 157 of the RAB7A protein (p.Lys157Asn). The lysine residue is highly conserved and there is a moderate physicochemical difference between lysine and asparagine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.050
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.63	D;.;T;T
Eigen	Uncertain	0.66
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.98	D;D;D;D
M_CAP	Pathogenic	0.38	D
MetaRNN	Pathogenic	0.96	D;D;D;D
MetaSVM	Pathogenic	0.92	D
MutationAssessor	Pathogenic	3.4	M;.;.;.
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-4.7	D;D;D;D
REVEL	Pathogenic	0.84
Sift	Pathogenic	0.0	D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D
Polyphen		1.0	D;D;.;.
Vest4		0.81
MutPred		0.87		Loss of ubiquitination at K157 (P = 0.011);.;.;.;
MVP		0.82
MPC		2.1
ClinPred		0.98	D
GERP RS		4.2
Varity_R		0.97
gMVP		0.77

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: rs121909081; hg19: chr3-128526457;