chrX-85864690-A-G

Position:

• chrX-85864690-A-G

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 0P and 11B. BP4_Strong BP6_Moderate BP7 BS2

The NM_000390.4(CHM):​c.1902T>C​(p.Ala634=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000073 in 1,096,566 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 2 hemizygotes in GnomAD. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: not found (cov: 24)
  • Exomes 𝑓: 0.0000073 (0 hom. 2 hem.)
• Consequence: CHM NM_000390.4 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.601

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]

ACMG classification

Verdict is Benign. Variant got -11 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.87).
• BP6: Variant X-85864690-A-G is Benign according to our data. Variant chrX-85864690-A-G is described in ClinVar as [Likely_benign]. Clinvar id is 1094270.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=-0.601 with no splicing effect.
• BS2: High Hemizygotes in GnomAdExome4 at 2 XL gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHM	NM_000390.4	c.1902T>C	p.Ala634=	synonymous_variant	15/15	ENST00000357749.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHM	ENST00000357749.7	c.1902T>C	p.Ala634=	synonymous_variant	15/15	1	NM_000390.4	P1
CHM	ENST00000467744.2	n.127-1596T>C		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome AF: 0.00000730 AC: 8 AN: 1096566 Hom.: 0 Cov.: 29 AF XY: 0.00000552 AC XY: 2 AN XY: 362098

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: 0.000149

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 24

Bravo AF: 0.00000378

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 28, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.87
CADD	Benign	2.2
DANN	Benign	0.48

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: rs1923575584; hg19: chrX-85119695;