chr20-2309687-C-G

Variant names:

• chr20-2309687-C-G
• rs214803
• NM_003245.4:c.38C>G

Variant summary

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

The NM_003245.4(TGM3):​c.38C>G​(p.Thr13Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,812 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T13K) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TGM3 NM_003245.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -2.43
• Publications: 37 publications found

Genes affected

TGM3 (HGNC:11779): (transglutaminase 3) Transglutaminases are enzymes that catalyze the crosslinking of proteins by epsilon-gamma glutamyl lysine isopeptide bonds. While the primary structure of transglutaminases is not conserved, they all have the same amino acid sequence at their active sites and their activity is calcium-dependent. The protein encoded by this gene consists of two polypeptide chains activated from a single precursor protein by proteolysis. The encoded protein is involved the later stages of cell envelope formation in the epidermis and hair follicle. [provided by RefSeq, Jul 2008]

TGM3 Gene-Disease associations (from GenCC):

• uncombable hair syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• uncombable hair syndrome 2

  Inheritance: AR Classification: LIMITED Submitted by: G2P

ENSG00000286022 (HGNC:):

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=0.09499392).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003245.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TGM3	NM_003245.4	MANE Select	c.38C>G	p.Thr13Arg	missense	Exon 2 of 13	NP_003236.3

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TGM3	ENST00000381458.6	TSL:1 MANE Select	c.38C>G	p.Thr13Arg	missense	Exon 2 of 13	ENSP00000370867.5
	ENSG00000286022	ENST00000651531.1		c.95C>G	p.Thr32Arg	missense	Exon 3 of 14	ENSP00000498584.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251430 AF XY: 0.00000736

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461812 Hom.: 0 Cov.: 67 AF XY: 0.00000138 AC XY: 1 AN XY: 727200

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5722

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111988

Other (OTH) AF: 0.0000166 AC: 1 AN: 60390

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00000160 Hom.: 199322

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.082
BayesDel_addAF	Benign	-0.15	T
BayesDel_noAF	Benign	-0.45
CADD	Benign	0.0090
DANN	Benign	0.67
DEOGEN2	Benign	0.18	T
Eigen	Benign	-0.98
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.033	N
LIST_S2	Benign	0.15	T
M_CAP	Benign	0.082	D
MetaRNN	Benign	0.095	T
MetaSVM	Benign	-0.68	T
MutationAssessor	Benign	0.0	N
PhyloP100		-2.4
PrimateAI	Benign	0.30	T
PROVEAN	Benign	-0.31	N
REVEL	Benign	0.28
Sift	Benign	0.60	T
Sift4G	Benign	0.54	T
Polyphen		0.97	D
Vest4		0.17
MutPred		0.31		Gain of MoRF binding (P = 0.0064)
MVP		0.72
MPC		0.16
ClinPred		0.16	T
GERP RS		-1.1
Varity_R		0.22
gMVP		0.43
Mutation Taster		=92/8	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs214803; hg19: chr20-2290333;