Genetic Variant TTC22:p.Lys222Glu (chr1-54787786-T-C) – ACMG Classification: Likely_benign (-4 pts)

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_001114108.2(TTC22):c.664A>G(p.Lys222Glu) variant causes a missense change. The variant allele was found at a frequency of 0.0000434 in 1,613,066 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000047 ( 1 hom. )

Consequence

TTC22
NM_001114108.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.49

Publications

1 publications found

Variant links:

Genes affected

TTC22 (HGNC:26067): (tetratricopeptide repeat domain 22) This gene encodes a protein with seven tetratricopeptide (TPR) repeats. Tetratricopeptide repeat containing motifs are found in a variety of proteins and may mediate protein-protein interactions and chaperone activity. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Jun 2011]

TTC22 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.033491433).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTC22	NM_001114108.2 link	c.664A>G	p.Lys222Glu	missense_variant	Exon 3 of 7	ENST00000371276.9	NP_001107580.1	Q5TAA0-1
TTC22	NM_017904.4 link	c.664A>G	p.Lys222Glu	missense_variant	Exon 3 of 6		NP_060374.2	Q5TAA0-2
TTC22	XM_011541671.3 link	c.664A>G	p.Lys222Glu	missense_variant	Exon 3 of 6		XP_011539973.1
TTC22	XM_017001582.2 link	c.91A>G	p.Lys31Glu	missense_variant	Exon 3 of 7		XP_016857071.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTC22	ENST00000371276.9 link	c.664A>G	p.Lys222Glu	missense_variant	Exon 3 of 7	5	NM_001114108.2	ENSP00000360323.4		Q5TAA0-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152156

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000386

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000602

AC:

AN:

248970

AF XY:

0.0000817

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000765

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000466

AC:

AN:

1460792

Hom.:

Cov.:

AF XY:

0.0000523

AC XY:

AN XY:

726606

show subpopulations

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

African (AFR)

AF:

0.00

AC:

AN:

33452

American (AMR)

AF:

0.00

AC:

AN:

44594

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26068

East Asian (EAS)

AF:

0.00151

AC:

AN:

39654

South Asian (SAS)

AF:

0.0000930

AC:

AN:

85994

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53326

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111600

Other (OTH)

AF:

0.00

AC:

AN:

60338

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.342

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152274

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74456

show subpopulations

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

African (AFR)

AF:

0.00

AC:

AN:

41546

American (AMR)

AF:

0.00

AC:

AN:

15306

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.000387

AC:

AN:

5174

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10628

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68008

Other (OTH)

AF:

0.00

AC:

AN:

2108

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.400

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

ExAC

AF:

0.0000741

AC:

Asia WGS

AF:

0.000577

AC:

AN:

3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jun 09, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.664A>G (p.K222E) alteration is located in exon 3 (coding exon 3) of the TTC22 gene. This alteration results from a A to G substitution at nucleotide position 664, causing the lysine (K) at amino acid position 222 to be replaced by a glutamic acid (E). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.14

BayesDel_addAF

Benign

-0.39

BayesDel_noAF

Benign

-0.41

CADD

Benign

(source)

DANN

Uncertain

0.99

DEOGEN2

Benign

0.0084

T;.;.

Eigen

Benign

-0.30

Eigen_PC

Benign

-0.11

FATHMM_MKL

Uncertain

0.87

LIST_S2

Benign

0.74

T;T;T

M_CAP

Benign

0.0051

MetaRNN

Benign

0.033

T;T;T

MetaSVM

Benign

-1.1

MutationAssessor

Benign

1.6

L;L;.

PhyloP100

4.5

PrimateAI

Benign

0.47

PROVEAN

Benign

-0.77

N;N;N

REVEL

Benign

0.054

Sift

Benign

0.53

T;T;D

Sift4G

Benign

0.28

T;T;D

Polyphen

0.0060

B;B;.

Vest4

0.44

MutPred

0.16

Loss of methylation at K222 (P = 0.0131);Loss of methylation at K222 (P = 0.0131);.;

MVP

0.27

MPC

0.41

ClinPred

0.073

GERP RS

4.5

PromoterAI

-0.026

Neutral

(source)

Varity_R

0.21

gMVP

0.44

Mutation Taster

=83/17

polymorphism

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

chr1-54787786-T-C

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over