NM_025250.3:c.889C>T

Variant names:

• chr7-2652204-C-T
• rs138174391
• NM_025250.3:c.889C>T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_025250.3(TTYH3):​c.889C>T​(p.Leu297Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,460,970 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000027 (1 hom.)
• Consequence: TTYH3 NM_025250.3 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.01
• Publications: 0 publications found

Genes affected

TTYH3 (HGNC:22222): (tweety family member 3) This gene encodes a member of the tweety family of proteins. Members of this family function as chloride anion channels. The encoded protein functions as a calcium(2+)-activated large conductance chloride(-) channel. [provided by RefSeq, Jul 2008]

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.57).
• BP7: Synonymous conserved (PhyloP=2.01 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_025250.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTYH3	NM_025250.3	MANE Select	c.889C>T	p.Leu297Leu	synonymous	Exon 8 of 14	NP_079526.1	Q9C0H2-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTYH3	ENST00000258796.12	TSL:1 MANE Select	c.889C>T	p.Leu297Leu	synonymous	Exon 8 of 14	ENSP00000258796.7	Q9C0H2-1
	TTYH3	ENST00000913086.1		c.1198C>T	p.Leu400Leu	synonymous	Exon 9 of 15	ENSP00000583145.1
	TTYH3	ENST00000913085.1		c.889C>T	p.Leu297Leu	synonymous	Exon 8 of 15	ENSP00000583144.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000120 AC: 3 AN: 249864 AF XY: 0.0000148

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: 0.0000468

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1460970 Hom.: 1 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 726804

⚠️ 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: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.0000348 AC: 3 AN: 86256

European-Finnish (FIN) AF: 0.0000190 AC: 1 AN: 52606

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5708

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

Other (OTH) AF: 0.00 AC: 0 AN: 60380

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.0448430), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.57
CADD	Benign	7.0
DANN	Benign	0.47
PhyloP100		2.0
Mutation Taster		=100/0	polymorphism

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

Other links and lift over

dbSNP: rs138174391; hg19: chr7-2691838;