NM_024753.5:c.*1123dupT

Variant names:

• chr2-165873631-T-TA
• rs886055020
• NM_024753.5:c.*1123dupT

Variant summary

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

The NM_024753.5(TTC21B):​c.*1123dupT variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: TTC21B NM_024753.5 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 0.525
• Publications: 0 publications found

Genes affected

TTC21B (HGNC:25660): (tetratricopeptide repeat domain 21B) This gene encodes a member of TTC21 family, containing several tetratricopeptide repeat (TPR) domains. This protein is localized to the cilium axoneme, and may play a role in retrograde intraflagellar transport in cilia. Mutations in this gene are associated with various ciliopathies, nephronophthisis 12, and asphyxiating thoracic dystrophy 4. [provided by RefSeq, Oct 2011]

TTC21B Gene-Disease associations (from GenCC):

• asphyxiating thoracic dystrophy 4

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• nephronophthisis 12

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
• Jeune syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• nephronophthisis 2

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_024753.5. 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
	TTC21B	NM_024753.5	MANE Select	c.*1123dupT		3_prime_UTR	Exon 29 of 29	NP_079029.3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTC21B	ENST00000243344.8	TSL:1 MANE Select	c.*1123dupT		3_prime_UTR	Exon 29 of 29	ENSP00000243344.7	Q7Z4L5-1
	TTC21B	ENST00000959804.1		c.*1123dupT		3_prime_UTR	Exon 28 of 28	ENSP00000629863.1
	TTC21B	ENST00000679799.1		c.3806-2612dupT		intron	N/A	ENSP00000505208.1	A0A494C0N4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 0

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Jeune thoracic dystrophy (1)
-	1	-	Joubert syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.53

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: rs886055020; hg19: chr2-166730141;