11-102577412-A-G

Variant names:

• chr11-102577412-A-G
• rs768247344
• NM_004771.4:c.1366T>C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_004771.4(MMP20):​c.1366T>C​(p.Phe456Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000411 in 1,461,018 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: MMP20 NM_004771.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.45

Genes affected

MMP20 (HGNC:7167): (matrix metallopeptidase 20) Proteins of the matrix metalloproteinase (MMP) family are involved in the breakdown of extracellular matrix in normal physiological processes, such as embryonic development, reproduction, and tissue remodeling, as well as in disease processes, such as arthritis and metastasis. Most MMP's are secreted as inactive proproteins which are activated when cleaved by extracellular proteinases. The protein encoded by this gene degrades amelogenin, the major protein component of dental enamel matrix, and thus thought to play a role in tooth enamel formation. A mutation in this gene, which alters the normal splice pattern and results in premature termination of the encoded protein, has been associated with amelogenesis imperfecta. This gene is part of a cluster of MMP genes located on chromosome 11q22.3. [provided by RefSeq, Aug 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.746

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MMP20	NM_004771.4	c.1366T>C	p.Phe456Leu	missense_variant	Exon 10 of 10	ENST00000260228.3	NP_004762.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MMP20	ENST00000260228.3	c.1366T>C	p.Phe456Leu	missense_variant	Exon 10 of 10	1	NM_004771.4	ENSP00000260228.2
MMP20	ENST00000542305.1	n.264T>C		non_coding_transcript_exon_variant	Exon 3 of 3	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251174 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135772

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: 0.0000654

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.00000411 AC: 6 AN: 1461018 Hom.: 0 Cov.: 30 AF XY: 0.00000413 AC XY: 3 AN XY: 726894

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: 0.0000696

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Alfa AF: 0.000111 Hom.: 0

ExAC AF: 0.00000824 AC: 1

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Jan 04, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1366T>C (p.F456L) alteration is located in exon 10 (coding exon 10) of the MMP20 gene. This alteration results from a T to C substitution at nucleotide position 1366, causing the phenylalanine (F) at amino acid position 456 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Amelogenesis imperfecta hypomaturation type 2A2 Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Benign	-0.019	T
BayesDel_noAF	Uncertain	-0.080
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.18	T
Eigen	Pathogenic	0.76
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Benign	0.65	T
M_CAP	Benign	0.016	T
MetaRNN	Pathogenic	0.75	D
MetaSVM	Benign	-0.80	T
MutationAssessor	Benign	1.9	L
PrimateAI	Uncertain	0.73	T
PROVEAN	Pathogenic	-5.3	D
REVEL	Uncertain	0.46
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.028	D
Polyphen		1.0	D
Vest4		0.66
MutPred		0.71		Loss of glycosylation at S457 (P = 0.1233);
MVP		0.62
MPC		0.25
ClinPred		0.95	D
GERP RS		5.1
Varity_R		0.90
gMVP		0.85

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: rs768247344; hg19: chr11-102448143;