12-49046422-C-T

Variant names:

• chr12-49046422-C-T
• rs587783718
• NM_003482.4:c.4421G>A

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PP3_Strong PP5

The NM_003482.4(KMT2D):​c.4421G>A​(p.Cys1474Tyr) variant causes a missense, splice region 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. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: KMT2D NM_003482.4 missense, splice_region
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:2
• Conservation: PhyloP100: 7.89

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 Likely_pathogenic. Variant got 9 ACMG points.

• PM1: In a zinc_finger_region PHD-type 5 (size 50) in uniprot entity KMT2D_HUMAN there are 8 pathogenic changes around while only 1 benign (89%) in NM_003482.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.977
• PP5: Variant 12-49046422-C-T is Pathogenic according to our data. Variant chr12-49046422-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 158770.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KMT2D	NM_003482.4	c.4421G>A	p.Cys1474Tyr	missense_variant, splice_region_variant	Exon 17 of 55	ENST00000301067.12	NP_003473.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KMT2D	ENST00000301067.12	c.4421G>A	p.Cys1474Tyr	missense_variant, splice_region_variant	Exon 17 of 55	5	NM_003482.4	ENSP00000301067.7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Kabuki syndrome 1 Pathogenic:1

Feb 08, 2013

Genetic Services Laboratory, University of Chicago

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

KMT2D-related disorder Pathogenic:1

Sep 25, 2024

PreventionGenetics, part of Exact Sciences

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The KMT2D c.4421G>A variant is predicted to result in the amino acid substitution p.Cys1474Tyr. This variant has been reported in at least one individual with Kabuki syndrome (Faundes et al. 2019. PubMed ID: 30459467). This variant has not been reported in a large population database, indicating this variant is rare. This variant is interpreted as likely pathogenic. -

Kabuki syndrome Uncertain:1

Jan 09, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces cysteine with tyrosine at codon 1474 of the KMT2D protein (p.Cys1474Tyr). The cysteine residue is highly conserved and there is a large physicochemical difference between cysteine and tyrosine. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. This variant is not present in population databases (ExAC no frequency). This variant has been observed in individual(s) with Kabuki syndrome (PMID: 30459467). ClinVar contains an entry for this variant (Variation ID: 158770). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). -

not provided Uncertain:1

Mar 24, 2016

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
CADD	Uncertain	24
DANN	Benign	0.93
DEOGEN2	Benign	0.30	T
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.85	T
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	0.95	D
MutationAssessor	Pathogenic	3.9	H
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-9.4	D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.95
MVP		0.98
MPC		3.2
ClinPred		1.0	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.89
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs587783718; hg19: chr12-49440205;