rs1555968874

Variant names:

• chrX-86027529-TGCA-T
• rs1555968874
• NM_000390.4:c.75_77delTGC

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2 PM4_Supporting PP5_Moderate

The NM_000390.4(CHM):​c.75_77delTGC​(p.Ala26del) variant causes a disruptive inframe deletion change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 22)
• Consequence: CHM NM_000390.4 disruptive_inframe_deletion
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.79
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• choroideremia

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, G2P, ClinGen, Illumina

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_000390.4. Strenght limited to Supporting due to length of the change: 1aa.
• PP5: Variant X-86027529-TGCA-T is Pathogenic according to our data. Variant chrX-86027529-TGCA-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 523365.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHM	NM_000390.4	c.75_77delTGC	p.Ala26del	disruptive_inframe_deletion	Exon 2 of 15	ENST00000357749.7	NP_000381.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHM	ENST00000357749.7	c.75_77delTGC	p.Ala26del	disruptive_inframe_deletion	Exon 2 of 15	1	NM_000390.4	ENSP00000350386.2
CHM	ENST00000615443.1	c.75_77delTGC	p.Ala26del	disruptive_inframe_deletion	Exon 2 of 5	1		ENSP00000484306.1
CHM	ENST00000467744.2	n.85_87delTGC		non_coding_transcript_exon_variant	Exon 2 of 3	5
CHM	ENST00000483950.1	n.104_106delTGC		non_coding_transcript_exon_variant	Exon 2 of 2	3

Frequencies

GnomAD3 genomes Cov.: 22

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 22

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Night blindness;C4048273:Chorioretinal atrophy Pathogenic:1

Jan 01, 2017

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		5.8

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

Other links and lift over

dbSNP: rs1555968874; hg19: chrX-85282533;