rs1555038029

Positions:

• chr11-118477973-C-A

Variant summary

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

The NM_001197104.2(KMT2A):​c.3341C>A​(p.Ser1114Ter) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: KMT2A NM_001197104.2 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.52

Genes affected

KMT2A (HGNC:7132): (lysine methyltransferase 2A) This gene encodes a transcriptional coactivator that plays an essential role in regulating gene expression during early development and hematopoiesis. The encoded protein contains multiple conserved functional domains. One of these domains, the SET domain, is responsible for its histone H3 lysine 4 (H3K4) methyltransferase activity which mediates chromatin modifications associated with epigenetic transcriptional activation. This protein is processed by the enzyme Taspase 1 into two fragments, MLL-C and MLL-N. These fragments reassociate and further assemble into different multiprotein complexes that regulate the transcription of specific target genes, including many of the HOX genes. Multiple chromosomal translocations involving this gene are the cause of certain acute lymphoid leukemias and acute myeloid leukemias. Alternate splicing results in multiple transcript variants.[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 11-118477973-C-A is Pathogenic according to our data. Variant chr11-118477973-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 488383.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KMT2A	NM_001197104.2	c.3341C>A	p.Ser1114Ter	stop_gained	5/36	ENST00000534358.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KMT2A	ENST00000534358.8	c.3341C>A	p.Ser1114Ter	stop_gained	5/36	1	NM_001197104.2	P4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1461646 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 727148

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: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Wiedemann-Steiner syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Oct 24, 2017

A heterozygous variant was identified in exon 5 of the KMT2A gene, NM_001197104(KMT2A):c.3341C>A (chr11:118348688). This nonsense variant is predicted to create a change of a serine to a stop at amino acid position 1114, NP_001184033.1(KMT2A):p.(Ser1114*), resulting in a truncated protein. The serine at this position has high conservation and this substitution results in a substantial amino acid truncation which includes important domains of the protein. In silico software predicts this variant to be disease causing. This variant has not been previously observed in our patient cohort, is not present in population databases and has not been previosuly observed in other clinical cases. However, heterozygous truncating variants are associated with Wiedemann-Steiner syndrome and truncating variants downstream in the KMT2A gene have been reported as pathogenic (ClinVar). Parental testing confirmed this variant to be de novo. Based on current information this variant has been classified as PATHOGENIC. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	37
DANN	Uncertain	1.0
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	A;A;A
Vest4		0.85, 0.83
GERP RS		6.1

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: rs1555038029; hg19: chr11-118348688;