chrX-85864687-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_000390.4(CHM):​c.1905C>A​(p.Asn635Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 22)
Exomes 𝑓: 0.0000018 ( 0 hom. 1 hem. )
Failed GnomAD Quality Control

Consequence

CHM
NM_000390.4 missense

Scores

17

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.479
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]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.07551712).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
CHMNM_000390.4 linkuse as main transcriptc.1905C>A p.Asn635Lys missense_variant 15/15 ENST00000357749.7

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
CHMENST00000357749.7 linkuse as main transcriptc.1905C>A p.Asn635Lys missense_variant 15/151 NM_000390.4 P1P24386-1
CHMENST00000467744.2 linkuse as main transcriptn.127-1593C>A intron_variant, non_coding_transcript_variant 5

Frequencies

GnomAD3 genomes
Cov.:
22
GnomAD3 exomes
AF:
0.0000112
AC:
2
AN:
179191
Hom.:
0
AF XY:
0.0000156
AC XY:
1
AN XY:
64171
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000147
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
Data not reliable, filtered out with message: AS_VQSR
AF:
0.00000182
AC:
2
AN:
1096549
Hom.:
0
Cov.:
29
AF XY:
0.00000276
AC XY:
1
AN XY:
362089
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000664
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
22
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingAmbry GeneticsApr 06, 2024The c.1905C>A (p.N635K) alteration is located in exon 15 (coding exon 15) of the CHM gene. This alteration results from a C to A substitution at nucleotide position 1905, causing the asparagine (N) at amino acid position 635 to be replaced by a lysine (K). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.080
BayesDel_addAF
Benign
-0.33
T
BayesDel_noAF
Benign
-0.71
CADD
Benign
5.9
DANN
Benign
0.17
DEOGEN2
Benign
0.11
T
FATHMM_MKL
Benign
0.52
D
LIST_S2
Benign
0.65
T
M_CAP
Benign
0.027
D
MetaRNN
Benign
0.076
T
MetaSVM
Benign
-0.85
T
MutationAssessor
Benign
0.97
L
MutationTaster
Benign
0.85
N;N
PrimateAI
Benign
0.34
T
PROVEAN
Benign
-0.030
N
REVEL
Benign
0.21
Sift
Benign
0.77
T
Sift4G
Benign
0.94
T
Polyphen
0.0
B
Vest4
0.061
MutPred
0.24
Gain of ubiquitination at N635 (P = 7e-04);
MVP
0.75
MPC
0.30
ClinPred
0.015
T
GERP RS
1.4
Varity_R
0.065
gMVP
0.15

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.

Other links and lift over

dbSNP: rs772394005; hg19: chrX-85119692; API