X-85864685-G-A

Position:

chrX-85864685-G-A

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_ModerateBS2

The NM_000390.4(CHM):c.1907C>T(p.Ser636Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000662 in 1,207,834 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 3 hemizygotes in GnomAD. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. S636S) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000090 ( 0 hom., 0 hem., cov: 23)

Exomes 𝑓: 0.0000064 ( 0 hom. 3 hem. )

Consequence

CHM
NM_000390.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.12

Variant links:

Genes affected

CHM (HGNC:1940): (CHM Rab escort protein) This gene encodes component A of the RAB geranylgeranyl transferase holoenzyme. In the dimeric holoenzyme, this subunit binds unprenylated Rab GTPases and then presents them to the catalytic Rab GGTase subunit for the geranylgeranyl transfer reaction. Rab GTPases need to be geranylgeranyled on either one or two cysteine residues in their C-terminus to localize to the correct intracellular membrane. Mutations in this gene are a cause of choroideremia; also known as tapetochoroidal dystrophy (TCD). This X-linked disease is characterized by progressive dystrophy of the choroid, retinal pigment epithelium and retina. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Mar 2016]

CHM links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -6 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.18949777).

BS2

High Hemizygotes in GnomAdExome4 at 3 XL gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHM	NM_000390.4 linkuse as main transcript	c.1907C>T	p.Ser636Leu	missense_variant	15/15	ENST00000357749.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHM	ENST00000357749.7 linkuse as main transcript	c.1907C>T	p.Ser636Leu	missense_variant	15/15	1	NM_000390.4	P1	P24386-1
CHM	ENST00000467744.2 linkuse as main transcript	n.127-1591C>T		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes

AF:

0.00000898

AC:

AN:

111343

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

33529

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:

0.0000188

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000558

AC:

AN:

179238

Hom.:

AF XY:

0.00

AC XY:

AN XY:

64240

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000638

AC:

AN:

1096491

Hom.:

Cov.:

AF XY:

0.00000829

AC XY:

AN XY:

362073

show subpopulations

Gnomad4 AFR exome

AF:

0.0000379

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000186

Gnomad4 FIN exome

AF:

0.0000247

Gnomad4 NFE exome

AF:

0.00000476

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000898

AC:

AN:

111343

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

33529

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000188

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 30, 2021

This sequence change replaces serine with leucine at codon 636 of the CHM protein (p.Ser636Leu). The serine residue is weakly conserved and there is a large physicochemical difference between serine and leucine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with CHM-related conditions. 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 tolerated. 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

Benign

0.070

BayesDel_addAF

Benign

-0.063

BayesDel_noAF

Benign

-0.33

CADD

Benign

DANN

Benign

0.96

DEOGEN2

Benign

0.31

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Benign

0.73

M_CAP

Benign

0.055

MetaRNN

Benign

0.19

MetaSVM

Uncertain

0.012

MutationAssessor

Benign

1.4

MutationTaster

Benign

0.67

N;N

PrimateAI

Benign

0.31

PROVEAN

Benign

-2.0

REVEL

Benign

0.24

Sift

Benign

0.34

Sift4G

Benign

0.31

Polyphen

0.0020

Vest4

0.11

MutPred

0.24

Loss of phosphorylation at S636 (P = 0.0172);

MVP

0.79

MPC

0.25

ClinPred

0.29

GERP RS

4.9

Varity_R

0.27

gMVP

0.35

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over