12-49033482-TTGCTGCTGCTGC-TTGCTGCTGC

Variant names:

• chr12-49033482-TTGC-T
• rs398123707
• NM_003482.4:c.11220_11222delGCA

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP3

The NM_003482.4(KMT2D):​c.11220_11222delGCA​(p.Gln3741del) variant causes a disruptive inframe deletion change. The variant allele was found at a frequency of 0.0000205 in 1,609,696 control chromosomes in the GnomAD database, with no homozygous occurrence. There is a variant allele frequency bias in the population database for this variant (GnomAdExome4), which may indicate mosaicism or somatic mutations in the reference population data. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000022 (0 hom.)
• Consequence: KMT2D NM_003482.4 disruptive_inframe_deletion
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 B:1
• Conservation: PhyloP100: 5.57
• Publications: 2 publications found

Genes affected

KMT2D (HGNC:7133): (lysine methyltransferase 2D) The protein encoded by this gene is a histone methyltransferase that methylates the Lys-4 position of histone H3. The encoded protein is part of a large protein complex called ASCOM, which has been shown to be a transcriptional regulator of the beta-globin and estrogen receptor genes. Mutations in this gene have been shown to be a cause of Kabuki syndrome. [provided by RefSeq, Oct 2010]

KMT2D Gene-Disease associations (from GenCC):

• choanal atresia-athelia-hypothyroidism-delayed puberty-short stature syndrome

  Inheritance: AD Classification: DEFINITIVE, MODERATE Submitted by: Illumina, G2P
• Kabuki syndrome 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Laboratory for Molecular Medicine, ClinGen, Labcorp Genetics (formerly Invitae), Ambry Genetics
• branchial arch abnormalities, choanal atresia, athelia, hearing loss, and hypothyroidism syndrome

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• Kabuki syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• BP3: Nonframeshift variant in repetitive region in NM_003482.4

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003482.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KMT2D	NM_003482.4	MANE Select	c.11220_11222delGCA	p.Gln3741del	disruptive_inframe_deletion	Exon 40 of 55	NP_003473.3

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KMT2D	ENST00000301067.12	TSL:5 MANE Select	c.11220_11222delGCA	p.Gln3741del	disruptive_inframe_deletion	Exon 40 of 55	ENSP00000301067.7
	KMT2D	ENST00000683543.2		c.11220_11222delGCA	p.Gln3741del	disruptive_inframe_deletion	Exon 40 of 56	ENSP00000506726.1
	KMT2D	ENST00000685166.1		c.11229_11231delGCA	p.Gln3744del	disruptive_inframe_deletion	Exon 39 of 54	ENSP00000509386.1

Frequencies

GnomAD3 genomes AF: 0.00000659 AC: 1 AN: 151750 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000242

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.000214 AC: 50 AN: 233912 AF XY: 0.000228

Gnomad AFR exome AF: 0.000281

Gnomad AMR exome AF: 0.000276

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000118

Gnomad FIN exome AF: 0.000146

Gnomad NFE exome AF: 0.000287

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000219 AC: 32 AN: 1457946 Hom.: 0 AF XY: 0.0000290 AC XY: 21 AN XY: 725278

⚠️ 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: 33410

American (AMR) AF: 0.000136 AC: 6 AN: 44192

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26076

East Asian (EAS) AF: 0.00 AC: 0 AN: 39610

South Asian (SAS) AF: 0.0000465 AC: 4 AN: 86026

European-Finnish (FIN) AF: 0.0000378 AC: 2 AN: 52898

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5752

European-Non Finnish (NFE) AF: 0.0000180 AC: 20 AN: 1109764

Other (OTH) AF: 0.00 AC: 0 AN: 60218

⚠️ 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 AF: 0.00000659 AC: 1 AN: 151750 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74118

African (AFR) AF: 0.0000242 AC: 1 AN: 41316

American (AMR) AF: 0.00 AC: 0 AN: 15256

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3464

East Asian (EAS) AF: 0.00 AC: 0 AN: 5136

South Asian (SAS) AF: 0.00 AC: 0 AN: 4818

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10584

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67876

Other (OTH) AF: 0.00 AC: 0 AN: 2078

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Sep 25, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports a deleterious effect on protein structure/function; In-frame deletion of 1 amino acid in a repetitive region with no known function; Has not been previously published as pathogenic or benign to our knowledge

KMT2D-related disorder Benign:1

Oct 08, 2020

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications).

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		5.6
Mutation Taster		=50/50

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs398123707; hg19: chr12-49427265; COSMIC: COSV99982086; COSMIC: COSV99982086;