rs1555192751

chr12-49041175-AG-Achr12-49041175-AG-AGG

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_003482.4(KMT2D):c.6594del(p.Tyr2199IlefsTer65) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000732 in 1,366,464 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. P2198P) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.3e-7 (0 hom.)
• Consequence: KMT2D NM_003482.4 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 0.218

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 12 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 12-49041175-AG-A is Pathogenic according to our data. Variant chr12-49041175-AG-A is described in ClinVar as [Pathogenic]. Clinvar id is 531891.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr12-49041175-AG-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KMT2D	NM_003482.4	c.6594del	p.Tyr2199IlefsTer65	frameshift_variant	32/55	ENST00000301067.12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KMT2D	ENST00000301067.12	c.6594del	p.Tyr2199IlefsTer65	frameshift_variant	32/55	5	NM_003482.4	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 7.32e-7 AC: 1 AN: 1366464 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 670282

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.0000202

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Kabuki syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Sep 06, 2017

This sequence change creates a premature translational stop signal (p.Tyr2199Ilefs*65) in the KMT2D gene. It is expected to result in an absent or disrupted protein product. This variant is not present in population databases (ExAC no frequency). This variant has been reported in the literature in an individual affected with Kabuki syndrome (PMID: 21671394). Loss-of-function variants in KMT2D are known to be pathogenic (PMID: 22126750). 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: rs1555192751; hg19: chr12-49434958;