chr12-49045937-A-G

Variant names:

• chr12-49045937-A-G
• rs1555194803
• NM_003482.4:c.4724T>C

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_003482.4(KMT2D):​c.4724T>C​(p.Met1575Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000205 in 1,461,640 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M1575L) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: KMT2D NM_003482.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: 5.69
• Publications: 0 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.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.13455433).
• BP6: Variant 12-49045937-A-G is Benign according to our data. Variant chr12-49045937-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 547424.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KMT2D	NM_003482.4	c.4724T>C	p.Met1575Thr	missense_variant	Exon 19 of 55	ENST00000301067.12	NP_003473.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KMT2D	ENST00000301067.12	c.4724T>C	p.Met1575Thr	missense_variant	Exon 19 of 55	5	NM_003482.4	ENSP00000301067.7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461640 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727106

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.0000671 AC: 3 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86248

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53402

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111816

Other (OTH) AF: 0.00 AC: 0 AN: 60370

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Kabuki syndrome Uncertain:1

Jan 27, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1575 of the KMT2D protein (p.Met1575Thr). 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: 547424). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt KMT2D protein function with a negative predictive value of 95%. 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. -

KMT2D-related disorder Uncertain:1

Mar 27, 2024

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

The KMT2D c.4724T>C variant is predicted to result in the amino acid substitution p.Met1575Thr. To our knowledge, this variant has not been reported in the literature or in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Kabuki syndrome 1 Benign:1

Nov 01, 2016

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

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Benign	-0.052	T
BayesDel_noAF	Benign	-0.31
CADD	Benign	21
DANN	Benign	0.91
DEOGEN2	Benign	0.039	T
Eigen	Benign	-0.18
Eigen_PC	Benign	0.085
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Benign	0.48	T
M_CAP	Uncertain	0.18	D
MetaRNN	Benign	0.13	T
MetaSVM	Benign	-0.79	T
MutationAssessor	Benign	-1.3	N
PhyloP100		5.7
PrimateAI	Benign	0.41	T
PROVEAN	Benign	0.78	N
REVEL	Uncertain	0.32
Sift	Benign	0.62	T
Polyphen		0.039	B
Vest4		0.38
MutPred		0.31		Gain of glycosylation at M1575 (P = 0.0044);
MVP		0.36
MPC		0.78
ClinPred		0.41	T
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.10
gMVP		0.43
Mutation Taster		=81/19	polymorphism

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: rs1555194803; hg19: chr12-49439720;