chr12-49049938-C-CT

Variant names:

• chr12-49049938-C-CT
• rs1555196084
• NM_003482.4:c.3649dupA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_003482.4(KMT2D):​c.3649dupA​(p.Ser1217LysfsTer33) variant causes a frameshift 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 Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: KMT2D NM_003482.4 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.37

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 12-49049938-C-CT is Pathogenic according to our data. Variant chr12-49049938-C-CT is described in ClinVar as [Likely_pathogenic]. Clinvar id is 547414.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KMT2D	NM_003482.4	c.3649dupA	p.Ser1217LysfsTer33	frameshift_variant	Exon 12 of 55	ENST00000301067.12	NP_003473.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KMT2D	ENST00000301067.12	c.3649dupA	p.Ser1217LysfsTer33	frameshift_variant	Exon 12 of 55	5	NM_003482.4	ENSP00000301067.7
KMT2D	ENST00000683543.2	c.3649dupA	p.Ser1217LysfsTer33	frameshift_variant	Exon 12 of 56			ENSP00000506726.1
KMT2D	ENST00000685166.1	c.3649dupA	p.Ser1217LysfsTer33	frameshift_variant	Exon 11 of 54			ENSP00000509386.1
KMT2D	ENST00000692637.1	c.3649dupA	p.Ser1217LysfsTer33	frameshift_variant	Exon 11 of 54			ENSP00000509666.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Kabuki syndrome 1 Pathogenic:1

Nov 01, 2016

Center for Human Genetics, Inc, Center for Human Genetics, Inc

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Kabuki syndrome Pathogenic:1

Nov 11, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Ser1217Lysfs*33) in the KMT2D gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in KMT2D are known to be pathogenic (PMID: 22126750). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with KMT2D-related conditions. ClinVar contains an entry for this variant (Variation ID: 547414). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

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

Publications

LitVar

Other links and lift over

dbSNP: rs1555196084; hg19: chr12-49443721;