12-49032227-G-C

Variant names:

• chr12-49032227-G-C
• rs1437975816
• NM_003482.4:c.12478C>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_003482.4(KMT2D):​c.12478C>G​(p.Leu4160Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,414 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L4160P) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: KMT2D NM_003482.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.33
• 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: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.18883872).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KMT2D	NM_003482.4	c.12478C>G	p.Leu4160Val	missense_variant	Exon 40 of 55	ENST00000301067.12	NP_003473.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KMT2D	ENST00000301067.12	c.12478C>G	p.Leu4160Val	missense_variant	Exon 40 of 55	5	NM_003482.4	ENSP00000301067.7

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461414 Hom.: 0 Cov.: 45 AF XY: 0.00000275 AC XY: 2 AN XY: 726960

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44710

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26112

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53334

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111724

Other (OTH) AF: 0.00 AC: 0 AN: 60352

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Kabuki syndrome Uncertain:1

Dec 18, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. 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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with KMT2D-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces leucine with valine at codon 4160 of the KMT2D protein (p.Leu4160Val). The leucine residue is moderately conserved and there is a small physicochemical difference between leucine and valine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.084
BayesDel_addAF	Benign	0.011	T
BayesDel_noAF	Benign	-0.22
CADD	Benign	16
DANN	Benign	0.84
DEOGEN2	Benign	0.038	T
Eigen	Benign	-0.042
Eigen_PC	Benign	0.040
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Benign	0.43	T
M_CAP	Pathogenic	0.48	D
MetaRNN	Benign	0.19	T
MetaSVM	Benign	-0.73	T
MutationAssessor	Benign	0.55	N
PhyloP100		2.3
PrimateAI	Benign	0.41	T
PROVEAN	Benign	-0.30	N
REVEL	Uncertain	0.31
Sift	Pathogenic	0.0	D
Polyphen		0.69	P
Vest4		0.28
MVP		0.45
MPC		0.15
ClinPred		0.26	T
GERP RS		3.2
Varity_R		0.16
gMVP		0.098
Mutation Taster		=84/16	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: rs1437975816; hg19: chr12-49426010;