NM_031889.3:c.123+2T>G

Variant names:

• chr4-70631740-T-G
• rs1553887511
• NM_031889.3:c.123+2T>G

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PVS1_Moderate PM2 PP5

The NM_031889.3(ENAM):​c.123+2T>G variant causes a splice donor, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: ENAM NM_031889.3 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 3.92
• Publications: 1 publications found

Genes affected

ENAM (HGNC:3344): (enamelin) Dental enamel forms the outer cap of teeth and is the hardest substance found in vertebrates. This gene encodes the largest protein in the enamel matrix of developing teeth. The protein is involved in the mineralization and structural organization of enamel. Defects in this gene result in amelogenesis imperfect type 1C.[provided by RefSeq, Oct 2009]

ENAM Gene-Disease associations (from GenCC):

• amelogenesis imperfecta type 1B

  Inheritance: AD, SD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• amelogenesis imperfecta type 1C

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• amelogenesis imperfecta type 1

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.020122485 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.7, offset of -20, new splice context is: ttgGTaatt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 4-70631740-T-G is Pathogenic according to our data. Variant chr4-70631740-T-G is described in ClinVar as [Pathogenic]. Clinvar id is 517662.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ENAM	NM_031889.3	c.123+2T>G		splice_donor_variant, intron_variant	Intron 3 of 8	ENST00000396073.4	NP_114095.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ENAM	ENST00000396073.4	c.123+2T>G		splice_donor_variant, intron_variant	Intron 3 of 8	1	NM_031889.3	ENSP00000379383.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Amelogenesis imperfecta - hypoplastic autosomal dominant - local Pathogenic:1

Dec 23, 2017

Dental Genetics Laboratory, Seoul National University School of Dentistry

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.34
CADD	Pathogenic	30
DANN	Uncertain	0.99
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Uncertain	0.96	D
PhyloP100		3.9
GERP RS		5.5
Mutation Taster		=2/98	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.92
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.99		Position offset: -2

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

Other links and lift over

dbSNP: rs1553887511; hg19: chr4-71497457;