chr14-88824729-C-T

Variant names:

• chr14-88824729-C-T
• rs139659023
• NM_144596.4:c.22C>T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Moderate BP6_Moderate

The NM_001288782.1(TTC8):​c.-541C>T variant causes a 5 prime UTR premature start codon gain change. The variant allele was found at a frequency of 0.000036 in 1,610,510 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 Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000039 (0 hom.)
• Consequence: TTC8 NM_001288782.1 5_prime_UTR_premature_start_codon_gain
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 3.88
• Publications: 0 publications found

Genes affected

TTC8 (HGNC:20087): (tetratricopeptide repeat domain 8) This gene encodes a protein that has been directly linked to Bardet-Biedl syndrome. The primary features of this syndrome include retinal dystrophy, obesity, polydactyly, renal abnormalities and learning disabilities. Experimentation in non-human eukaryotes suggests that this gene is expressed in ciliated cells and that it is involved in the formation of cilia. A mutation in this gene has also been implicated in nonsyndromic retinitis pigmentosa. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2014]

TTC8 Gene-Disease associations (from GenCC):

• Bardet-Biedl syndrome 8

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P
• retinitis pigmentosa 51

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• TTC8-related ciliopathy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• retinitis pigmentosa

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Bardet-Biedl syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

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

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.35).
• BP6: Variant 14-88824729-C-T is Benign according to our data. Variant chr14-88824729-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 1158804.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001288782.1. 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
	TTC8	NM_144596.4	MANE Select	c.22C>T	p.Leu8Leu	synonymous	Exon 1 of 15	NP_653197.2
	TTC8	NM_001288782.1		c.-541C>T		5_prime_UTR_premature_start_codon_gain	Exon 2 of 14	NP_001275711.1	Q86U25
	TTC8	NM_001288783.1		c.-636C>T		5_prime_UTR_premature_start_codon_gain	Exon 2 of 15	NP_001275712.1	Q86U25

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTC8	ENST00000380656.7	TSL:2 MANE Select	c.22C>T	p.Leu8Leu	synonymous	Exon 1 of 15	ENSP00000370031.2	Q8TAM2-4
	TTC8	ENST00000338104.10	TSL:1	c.22C>T	p.Leu8Leu	synonymous	Exon 1 of 15	ENSP00000337653.6	A0A0C4DGX9
	TTC8	ENST00000622513.4	TSL:1	c.22C>T	p.Leu8Leu	synonymous	Exon 1 of 14	ENSP00000482721.1	A0A0C4DGY3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152134 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000248 AC: 6 AN: 241662 AF XY: 0.0000304

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: 0.0000184

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000391 AC: 57 AN: 1458376 Hom.: 0 Cov.: 31 AF XY: 0.0000483 AC XY: 35 AN XY: 725144

African (AFR) AF: 0.00 AC: 0 AN: 33422

American (AMR) AF: 0.00 AC: 0 AN: 44430

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26030

East Asian (EAS) AF: 0.00 AC: 0 AN: 39612

South Asian (SAS) AF: 0.0000585 AC: 5 AN: 85510

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52780

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5638

European-Non Finnish (NFE) AF: 0.0000468 AC: 52 AN: 1110732

Other (OTH) AF: 0.00 AC: 0 AN: 60222

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152134 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74322

African (AFR) AF: 0.00 AC: 0 AN: 41430

American (AMR) AF: 0.00 AC: 0 AN: 15282

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3462

East Asian (EAS) AF: 0.00 AC: 0 AN: 5160

South Asian (SAS) AF: 0.00 AC: 0 AN: 4836

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Likely benign

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	-	1	Bardet-Biedl syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.35
CADD	Benign	13
DANN	Benign	0.95
PhyloP100		3.9
PromoterAI		-0.019	Neutral

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: rs139659023; hg19: chr14-89291073;