chr3-69941238-G-A

Variant names:

• chr3-69941238-G-A
• rs1032758072
• NM_001354604.2:c.669G>A

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP6

The NM_001354604.2(MITF):​c.669G>A​(p.Met223Ile) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000263 in 1,445,170 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. M223V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000026 (0 hom.)
• Consequence: MITF NM_001354604.2 missense, splice_region
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: 4.83
• Publications: 1 publications found

Genes affected

MITF (HGNC:7105): (melanocyte inducing transcription factor) The protein encoded by this gene is a transcription factor that contains both basic helix-loop-helix and leucine zipper structural features. The encoded protein regulates melanocyte development and is responsible for pigment cell-specific transcription of the melanogenesis enzyme genes. Heterozygous mutations in the this gene cause auditory-pigmentary syndromes, such as Waardenburg syndrome type 2 and Tietz syndrome. [provided by RefSeq, Aug 2017]

MITF Gene-Disease associations (from GenCC):

• Tietz syndrome

  Inheritance: AD Classification: DEFINITIVE, MODERATE, SUPPORTIVE Submitted by: G2P, Orphanet, Ambry Genetics
• Waardenburg syndrome type 2

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• Waardenburg syndrome type 2A

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, G2P, Ambry Genetics
• melanoma, cutaneous malignant, susceptibility to, 8

  Inheritance: AD Classification: STRONG, MODERATE, LIMITED Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
• coloboma, osteopetrosis, microphthalmia, macrocephaly, albinism, and deafness

  Inheritance: AR Classification: STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P
• renal cell carcinoma

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• Waardenburg syndrome

  Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics
• Waardenburg-Shah syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• BP6: Variant 3-69941238-G-A is Benign according to our data. Variant chr3-69941238-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 547529.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MITF	NM_001354604.2	c.669G>A	p.Met223Ile	missense_variant, splice_region_variant	Exon 5 of 10	ENST00000352241.9	NP_001341533.1
MITF	NM_000248.4	c.348G>A	p.Met116Ile	missense_variant, splice_region_variant	Exon 4 of 9	ENST00000394351.9	NP_000239.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MITF	ENST00000352241.9	c.669G>A	p.Met223Ile	missense_variant, splice_region_variant	Exon 5 of 10	1	NM_001354604.2	ENSP00000295600.8
MITF	ENST00000394351.9	c.348G>A	p.Met116Ile	missense_variant, splice_region_variant	Exon 4 of 9	1	NM_000248.4	ENSP00000377880.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.0000263 AC: 38 AN: 1445170 Hom.: 0 Cov.: 28 AF XY: 0.0000264 AC XY: 19 AN XY: 720068

African (AFR) AF: 0.00 AC: 0 AN: 33058

American (AMR) AF: 0.00 AC: 0 AN: 44606

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26010

East Asian (EAS) AF: 0.00 AC: 0 AN: 39468

South Asian (SAS) AF: 0.00 AC: 0 AN: 85784

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53328

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5726

European-Non Finnish (NFE) AF: 0.0000346 AC: 38 AN: 1097430

Other (OTH) AF: 0.00 AC: 0 AN: 59760

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Tietz syndrome;C1860339:Waardenburg syndrome type 2A;C3152204:Melanoma, cutaneous malignant, susceptibility to, 8 Uncertain:1

Oct 23, 2024

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 isoleucine, which is neutral and non-polar, at codon 116 of the MITF protein (p.Met116Ile). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MITF-related conditions. ClinVar contains an entry for this variant (Variation ID: 547529). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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. -

MITF-related disorder Uncertain:1

Feb 02, 2024

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

The MITF c.348G>A variant is predicted to result in the amino acid substitution p.Met116Ile. 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. This variant is interpreted as likely benign by one submitter in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/547529/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

not provided Uncertain:1

Mar 20, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; In silico analysis suggests this variant may impact gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown; This variant is associated with the following publications: (PMID: 27640074) -

Waardenburg syndrome type 2A Benign:1

Nov 01, 2016

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

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.84
BayesDel_addAF	Uncertain	0.013	T
BayesDel_noAF	Benign	-0.22
CADD	Pathogenic	26
DANN	Benign	0.94
DEOGEN2	Uncertain	0.46	.;T;.;T;.;.;.;T;.;.;.
Eigen	Benign	0.17
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Benign	0.77	.;T;T;D;T;T;T;T;T;T;T
M_CAP	Benign	0.029	D
MetaRNN	Benign	0.24	T;T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.59	N;N;N;.;.;.;.;.;.;.;.
PhyloP100		4.8
PrimateAI	Pathogenic	0.84	D
PROVEAN	Benign	-1.2	N;N;.;N;N;N;N;N;N;N;N
REVEL	Benign	0.12
Sift	Benign	0.36	T;T;.;T;T;T;T;T;T;T;T
Sift4G	Benign	0.55	T;T;.;T;T;T;T;T;T;T;T
Polyphen		0.027	B;.;B;.;.;B;B;.;B;B;.
Vest4		0.47
MutPred		0.33		Loss of disorder (P = 0.0511);Loss of disorder (P = 0.0511);Loss of disorder (P = 0.0511);.;.;.;.;.;.;.;.;
MVP		0.56
MPC		0.45
ClinPred		0.66	D
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.32
gMVP		0.61
Mutation Taster		=53/47	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.26		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.26		Position offset: 2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1032758072; hg19: chr3-69990389;