chr8-60856027-GC-CT

Position:

• chr8-60856027-GC-CT

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2 PP2 PP3 BP6

The NM_017780.4(CHD7):​c.6989_6990delinsCT​(p.Gly2330Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in same amino acid change has been previously reported as Likely benignin ClinVar. Synonymous variant affecting the same amino acid position (i.e. G2330G) has been classified as Benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: CHD7 NM_017780.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:3
• Conservation: PhyloP100: 9.60

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), CHD7. . Gene score misZ 3.2193 (greater than the threshold 3.09). Trascript score misZ 3.9401 (greater than threshold 3.09). GenCC has associacion of gene with Kallmann syndrome, hypogonadotropic hypogonadism 5 with or without anosmia, CHARGE syndrome, hypogonadotropic hypogonadism, Omenn syndrome.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP
• BP6: Variant 8-60856027-GC-CT is Benign according to our data. Variant chr8-60856027-GC-CT is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 529148.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1, Benign=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CHD7	NM_017780.4	c.6989_6990delinsCT	p.Gly2330Ala	missense_variant	33/38	ENST00000423902.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CHD7	ENST00000423902.7	c.6989_6990delinsCT	p.Gly2330Ala	missense_variant	33/38	5	NM_017780.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

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

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 24, 2018

The c.6989_6990delGCinsCT variant (also known as p.G2330A), located in coding exon 32 of the CHD7 gene, results from an in-frame deletion of GC and insertion of CT at nucleotide positions 6989 to 6990. This results in the substitution of the glycine residue for an alanine residue at codon 2330, an amino acid with similar properties. In one study, c.6989G>C (p.G2330A) was reported as a rare missense variation of unknown pathogenicity identified in a cohort of samples submitted for CHD7 analysis (Bartels CF et al. Genet Test Mol Biomarkers, 2010 Dec;14:881-91). In another study, c.6989G>C (p.G2330A) was classified as a benign CHD7 missense variant present in two or more controls and/or found in the homozygous state; however, more specific information was not provided (Bergman JE et al. Hum. Mutat., 2012 Aug;33:1251-60). This amino acid position is highly conserved in available vertebrate species. Based on available evidence to date, the clinical significance of this alteration remains unclear. -

not specified Benign:1

Benign, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jul 27, 2018

The c.6989_6990delinsCT variant in CHD7 is classified as benign because it had b een identified in 0.26% (61/23434) of African chromosomes including 1 homozygote by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; d bSNP rs77704609 and rs559382275). ACMG/AMP Criteria applied: BA1. -

CHARGE syndrome Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 26, 2024

- -

not provided Benign:1

Benign, criteria provided, single submitter

clinical testing

GeneDx

Feb 12, 2019

- -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1554604771; hg19: chr8-61768586;