rs398124321
Variant summary
Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM2PP5_Very_Strong
The NM_017780.4(CHD7):c.5405-7G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000207 in 1,449,966 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★).
Frequency
Consequence
NM_017780.4 splice_region, intron
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 10 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
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CHD7 | ENST00000423902.7 | c.5405-7G>A | splice_region_variant, intron_variant | Intron 25 of 37 | 5 | NM_017780.4 | ENSP00000392028.1 | |||
CHD7 | ENST00000524602.5 | c.1717-11743G>A | intron_variant | Intron 2 of 4 | 1 | ENSP00000437061.1 | ||||
CHD7 | ENST00000695853.1 | n.5405-7G>A | splice_region_variant, intron_variant | Intron 25 of 36 | ENSP00000512218.1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome AF: 0.00000207 AC: 3AN: 1449966Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0AN XY: 718616
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
CHARGE syndrome Pathogenic:11
Variant summary: CHD7 c.5405-7G>A alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. One computational tool predicts that the variant creates a cryptic 3 acceptor site. Two independent mini-gene assays confirm the impact on splicing, specificaly the introduction of a 5-bp intronic sequence by activation of a cryptic acceptor site leading to a frameshift mutation (Legendre_2018, Song_2011). The variant was absent in 275496 control chromosomes (gnomAD). The variant, c.5405-7G>A, has been reported in the literature in multiple individuals affected with CHARGE Syndrome (Vissers_2004, Bilan_2012, Janssen_2012, Song_2011, Legendre_2018). These data indicate that the variant is very likely to be associated with disease. Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
found de novo on several CHARGE syndrome patients. Minigene assays confirm the use of a new acceptor splice site leading to frameshift in exon 26 -
ACMG categories: PS2,PS3,PM2,PP3,PP4,PP5 -
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This sequence change falls in intron 25 of the CHD7 gene. It does not directly change the encoded amino acid sequence of the CHD7 protein. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with CHARGE syndrome (PMID: 15300250, 16155193, 16615981, 21158681, 21931733, 22033296). In at least one individual the variant was observed to be de novo. This variant is also known as IVS25-7G>A and IVS26-7G>A. ClinVar contains an entry for this variant (Variation ID: 95795). Studies have shown that this variant alters mRNA splicing and is expected to lead to the loss of protein expression (PMID: 21931733). For these reasons, this variant has been classified as Pathogenic. -
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The variant is not observed in the gnomAD v2.1.1 dataset. Functional studies provide strong evidence of the variant having a damaging effect on the gene or gene product (PMID: 21931733). In silico tools predict the variant to alter splicing and produce an abnormal transcript (SpliceAI: 0.98). The variant has been previously reported as de novo in at least two similarly affected unrelated individuals (PMID: 15300250 , 22033296 ) and observed in multiple (>3) similarly affected unrelated individuals (PMID: 16155193 , 16615981 , 21158681 , 21931733). The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000095795). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -
not provided Pathogenic:6
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Published in vitro splicing assay and RT-PCR studies indicate this variant creates a new splice acceptor site in intron 25 that results in abnormal gene splicing resulting in a frameshift in the resultant product (Song et al., 2011; Legendre et al., 2018); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports a deleterious effect on splicing; This variant is associated with the following publications: (PMID: 30216942, 30587507, 31130284, 21931733, 21158681, 16155193, 29255276, 22033296, 15300250, 32763379, 34008892, 32969205, 16615981) -
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Inborn genetic diseases Pathogenic:1
The c.5405-7G>A intronic pathogenic mutation results from a G to A substitution 7 nucleotides upstream from coding exon 25 in the CHD7 gene. This mutation has been reported in multiple individuals with a clinical diagnosis of CHARGE syndrome, including one de novo occurrence (Vissers LE, et al. Nat. Genet. 2004 Sep; 36(9):955-7; Jongmans MC, et al. J. Med. Genet. 2006 Apr; 43(4):306-14; Aramaki M, et al. J. Pediatr. 2006 Mar; 148(3):410-4; Song MH, et al. PLoS ONE. 2011; 6(9):e24511). In addition, an in vitro splicing analysis demonstrated the introduction of 5 additional nucleotides due to the activation of a cryptic acceptor site (Song MH, et al. PLoS ONE. 2011; 6(9):e24511). Based on the supporting evidence, c.5405-7G>A is interpreted as a disease-causing mutation. -
CHD7-related disorder Pathogenic:1
The CHD7 c.5405-7G>A variant is predicted to interfere with splicing. This is a well-documented recurrent pathogenic variant causative for CHARGE syndrome and has previously been reported as de novo (Bilan et al. 2012. PubMed ID: 22033296; Song et al. 2011. PubMed ID: 21931733). Functional studies found it creates a frameshift and premature protein termination by activating a cryptic splice acceptor site and introducing a five-base pair intronic sequence to the CHD7 messenger RNA (Song et al. 2011. PubMed ID: 21931733; Legendre et al. 2018. PubMed ID: 29255276). This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. This variant is interpreted as pathogenic. -
Hypogonadotropic hypogonadism 5 with or without anosmia Pathogenic:1
The heterozygous c.5405-7G>A variant in CHD7 was identified by our study in one individual with hypogonadotropic hypogonadism with or without anosmia. Trio exome analysis showed this variant to be de novo and there are multiple reports of de novo inheritance in the literature (PMID: 15300250, 22033296). This variant was absent from large population studies and has been reported in ClinVar (Variation ID: 95795). In vitro functional studies provide some evidence that the c.5405-7G>A variant may impact protein function by causing a five base pair insertion during in vitro splicing (PMID: 21931733). However, these types of assays may not accurately represent biological function. In summary, the c.5405-7G>A variant is pathogenic based off of our findings and multiple de novo reports in the literature. ACMG/AMP Criteria applied: PM2, PS2, PM6_Strong, PS3_Moderate (Richards 2015). -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at