8-60821816-GTGT-GTGTTGT

Variant names:

• chr8-60821816-G-GTGT
• rs1554597381
• NM_017780.4:c.2726_2728dupGTT

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PM4_Supporting PP3

The NM_017780.4(CHD7):​c.2726_2728dupGTT​(p.Cys909dup) variant causes a disruptive inframe insertion 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 Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. S910S) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CHD7 NM_017780.4 disruptive_inframe_insertion
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.02
• 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: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_017780.4
• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_017780.4. Strenght limited to Supporting due to length of the change: 1aa.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHD7	NM_017780.4	c.2726_2728dupGTT	p.Cys909dup	disruptive_inframe_insertion	Exon 10 of 38	ENST00000423902.7	NP_060250.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHD7	ENST00000423902.7	c.2726_2728dupGTT	p.Cys909dup	disruptive_inframe_insertion	Exon 10 of 38	5	NM_017780.4	ENSP00000392028.1
CHD7	ENST00000524602.5	c.1717-40411_1717-40409dupGTT		intron_variant	Intron 2 of 4	1		ENSP00000437061.1
CHD7	ENST00000525508.1	c.2726_2728dupGTT	p.Cys909dup	disruptive_inframe_insertion	Exon 9 of 12	5		ENSP00000436027.1
CHD7	ENST00000695853.1	n.2726_2728dupGTT		non_coding_transcript_exon_variant	Exon 10 of 37			ENSP00000512218.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Feb 11, 2020

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed in large population cohorts (Lek et al., 2016); In-frame insertion of 1 amino acids in a non-repeat region; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		8.0

Splicing

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

Other links and lift over

dbSNP: rs1554597381; hg19: chr8-61734375;