15-93002203-GAAAA-GAAAAAAA

Variant names:

• chr15-93002203-G-GAAA
• rs749969667
• NM_001271.4:c.4171_4173dupAAA

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2 BP3

The NM_001271.4(CHD2):​c.4171_4173dupAAA​(p.Lys1391dup) variant causes a conservative inframe insertion change. The variant allele was found at a frequency of 0.00000072 in 1,389,818 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.2e-7 (0 hom.)
• Consequence: CHD2 NM_001271.4 conservative_inframe_insertion
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 4.43
• 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
• BP3: Nonframeshift variant in repetitive region in NM_001271.4

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CHD2	NM_001271.4	c.4171_4173dupAAA	p.Lys1391dup	conservative_inframe_insertion	Exon 33 of 39	ENST00000394196.9	NP_001262.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CHD2	ENST00000394196.9	c.4171_4173dupAAA	p.Lys1391dup	conservative_inframe_insertion	Exon 33 of 39	5	NM_001271.4	ENSP00000377747.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 7.20e-7 AC: 1 AN: 1389818 Hom.: 0 Cov.: 30 AF XY: 0.00000145 AC XY: 1 AN XY: 690164

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 30068

American (AMR) AF: 0.0000278 AC: 1 AN: 36022

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24190

East Asian (EAS) AF: 0.00 AC: 0 AN: 37252

South Asian (SAS) AF: 0.00 AC: 0 AN: 76558

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50994

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5474

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1072336

Other (OTH) AF: 0.00 AC: 0 AN: 56924

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		4.4

Splicing

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

Other links and lift over

dbSNP: rs749969667; hg19: chr15-93545433;