15-92939634-A-T

Variant names:

• chr15-92939634-A-T
• rs117844037
• NM_001271.4:c.608A>T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP4

The NM_001271.4(CHD2):​c.608A>T​(p.Lys203Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,882 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K203R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CHD2 NM_001271.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.831
• Publications: 0 publications found

Genes affected

CHD2 (HGNC:1917): (chromodomain helicase DNA binding protein 2) The CHD family of proteins is characterized by the presence of chromo (chromatin organization modifier) domains and SNF2-related helicase/ATPase domains. CHD genes alter gene expression possibly by modification of chromatin structure thus altering access of the transcriptional apparatus to its chromosomal DNA template. Alternatively spliced transcript variants encoding distinct isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

CHD2 Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• developmental and epileptic encephalopathy 94

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• Lennox-Gastaut syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• myoclonic-astatic epilepsy

  Inheritance: Unknown Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.26989827).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHD2	NM_001271.4	c.608A>T	p.Lys203Ile	missense_variant	Exon 7 of 39	ENST00000394196.9	NP_001262.3
CHD2	NM_001042572.3	c.608A>T	p.Lys203Ile	missense_variant	Exon 7 of 13		NP_001036037.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHD2	ENST00000394196.9	c.608A>T	p.Lys203Ile	missense_variant	Exon 7 of 39	5	NM_001271.4	ENSP00000377747.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461882 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 727240

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112010

Other (OTH) AF: 0.0000166 AC: 1 AN: 60394

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Aug 14, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge

Developmental and epileptic encephalopathy 94 Uncertain:1

Mar 02, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces lysine, which is basic and polar, with isoleucine, which is neutral and non-polar, at codon 203 of the CHD2 protein (p.Lys203Ile). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CHD2-related conditions. ClinVar contains an entry for this variant (Variation ID: 2135519). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt CHD2 protein function with a negative predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.40
BayesDel_addAF	Uncertain	0.074	D
BayesDel_noAF	Benign	-0.13
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.0	.;D;T;.;T
Eigen	Benign	0.023
Eigen_PC	Benign	0.077
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.93	D;D;D;D;D
M_CAP	Uncertain	0.16	D
MetaRNN	Benign	0.27	T;T;T;T;T
MetaSVM	Uncertain	0.37	D
MutationAssessor	Benign	1.7	L;L;.;L;.
PhyloP100		0.83
PrimateAI	Uncertain	0.53	T
PROVEAN	Benign	0.0	.;D;.;D;.
REVEL	Benign	0.0
Sift	Pathogenic	0.0	.;T;.;T;.
Sift4G	Uncertain	0.058	T;T;T;T;T
Vest4		0.38
ClinPred		0.74	D
GERP RS		2.7
PromoterAI		-0.024	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.10
gMVP		0.12

Splicing

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

Other links and lift over

dbSNP: rs117844037; hg19: chr15-93482864;