NM_017780.4:c.8744dupG

Variant names:

• chr8-60865677-T-TG
• rs1554607313
• NM_017780.4:c.8744dupG

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_017780.4(CHD7):​c.8744dupG​(p.Leu2916IlefsTer25) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CHD7 NM_017780.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 1.55
• Publications: 0 publications found

Genes affected

CHD7 (HGNC:20626): (chromodomain helicase DNA binding protein 7) This gene encodes a protein that contains several helicase family domains. Mutations in this gene have been found in some patients with the CHARGE syndrome. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2015]

CHD7 Gene-Disease associations (from GenCC):

• CHARGE syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, PanelApp Australia, Broad Center for Mendelian Genomics, ClinGen, G2P
• hypogonadotropic hypogonadism 5 with or without anosmia

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• hypogonadotropic hypogonadism

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Kallmann syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Omenn syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 4 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-60865677-T-TG is Pathogenic according to our data. Variant chr8-60865677-T-TG is described in ClinVar as Pathogenic. ClinVar VariationId is 547198.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHD7	NM_017780.4	c.8744dupG	p.Leu2916IlefsTer25	frameshift_variant	Exon 38 of 38	ENST00000423902.7	NP_060250.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHD7	ENST00000423902.7	c.8744dupG	p.Leu2916IlefsTer25	frameshift_variant	Exon 38 of 38	5	NM_017780.4	ENSP00000392028.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1454364 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 722422

African (AFR) AF: 0.00 AC: 0 AN: 33162

American (AMR) AF: 0.00 AC: 0 AN: 44240

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25746

East Asian (EAS) AF: 0.00 AC: 0 AN: 39576

South Asian (SAS) AF: 0.00 AC: 0 AN: 85824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53196

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5732

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1106910

Other (OTH) AF: 0.00 AC: 0 AN: 59978

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

CHARGE syndrome Pathogenic:2

Jan 22, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Leu2916Ilefs*25) in the CHD7 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 82 amino acid(s) of the CHD7 protein. This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with clinical features of CHARGE syndrome (PMID: 16155193). ClinVar contains an entry for this variant (Variation ID: 547198). This variant disrupts a region of the CHD7 protein in which other variant(s) (p.Asp2988Glyfs*2) have been determined to be pathogenic (PMID: 18073582, 31564432). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Nov 01, 2016

Center for Human Genetics, Inc, Center for Human Genetics, Inc

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:1

Jun 29, 2024

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Frameshift variant predicted to result in abnormal protein length as the last 82 amino acids are replaced with 24 different amino acids, and other similar variants have been reported in HGMD.; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 16400610, 16155193) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.5
Mutation Taster		=1/199	disease causing (ClinVar)

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: rs1554607313; hg19: chr8-61778236; COSMIC: COSV107521836; COSMIC: COSV107521836;