rs760000437

chr14-75032105-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001040108.2(MLH3):c.3790G>A(p.Glu1264Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,382 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 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. E1264D) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: MLH3 NM_001040108.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.35

Genes affected

MLH3 (HGNC:7128): (mutL homolog 3) This gene is a member of the MutL-homolog (MLH) family of DNA mismatch repair (MMR) genes. MLH genes are implicated in maintaining genomic integrity during DNA replication and after meiotic recombination. The protein encoded by this gene functions as a heterodimer with other family members. Somatic mutations in this gene frequently occur in tumors exhibiting microsatellite instability, and germline mutations have been linked to hereditary nonpolyposis colorectal cancer type 7 (HNPCC7). Several alternatively spliced transcript variants have been identified, but the full-length nature of only two transcript variants has been determined. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.22703704).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MLH3	NM_001040108.2	c.3790G>A	p.Glu1264Lys	missense_variant	8/13	ENST00000355774.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MLH3	ENST00000355774.7	c.3790G>A	p.Glu1264Lys	missense_variant	8/13	5	NM_001040108.2	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251462 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135908

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461382 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 727056

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: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Colorectal cancer, hereditary nonpolyposis, type 7 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 20, 2018

This sequence change replaces glutamic acid with lysine at codon 1264 of the MLH3 protein (p.Glu1264Lys). The glutamic acid residue is moderately conserved and there is a small physicochemical difference between glutamic acid and lysine. This variant is present in population databases (rs760000437, ExAC 0.001%). This variant has not been reported in the literature in individuals with MLH3-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The lysine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.010	T
BayesDel_noAF	Benign	-0.25
Cadd	Benign	22
Dann	Uncertain	1.0
DEOGEN2	Benign	0.086	T;.;T
Eigen	Benign	-0.13
Eigen_PC	Benign	0.030
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.89	D;D;.
M_CAP	Benign	0.020	T
MetaRNN	Benign	0.23	T;T;T
MetaSVM	Benign	-0.64	T
MutationAssessor	Benign	1.8	L;.;L
MutationTaster	Benign	0.67	D;D;D;D;D;N
PrimateAI	Benign	0.47	T
PROVEAN	Benign	-1.6	N;.;N
REVEL	Benign	0.18
Sift	Benign	0.16	T;.;T
Sift4G	Benign	0.062	T;T;T
Polyphen		0.0060	B;B;B
Vest4		0.18
MutPred		0.61		Gain of catalytic residue at P1261 (P = 0);.;Gain of catalytic residue at P1261 (P = 0);
MVP		0.83
MPC		0.16
ClinPred		0.86	D
GERP RS		5.0
Varity_R		0.14
gMVP		0.53

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: rs760000437; hg19: chr14-75498808;