5-150361152-GC-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Moderate PP5_Moderate

The NM_001371623.1(TCOF1):c.109-3del variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TCOF1 NM_001371623.1 splice_region, splice_polypyrimidine_tract, intron
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 2.55

Genes affected

TCOF1 (HGNC:11654): (treacle ribosome biogenesis factor 1) This gene encodes a nucleolar protein with a LIS1 homology domain. The protein is involved in ribosomal DNA gene transcription through its interaction with upstream binding factor (UBF). Mutations in this gene have been associated with Treacher Collins syndrome, a disorder which includes abnormal craniofacial development. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 5-150361152-GC-G is Pathogenic according to our data. Variant chr5-150361152-GC-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1067473.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TCOF1	NM_001371623.1	c.109-3del		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant		ENST00000643257.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TCOF1	ENST00000643257.2	c.109-3del		splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant			NM_001371623.1	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Treacher Collins syndrome 1 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Invitae

Oct 23, 2021

Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant has been observed in individual(s) with clinical features of Treacher Collins syndrome (Invitae). In at least one individual the variant was observed to be de novo. This variant is not present in population databases (ExAC no frequency). This sequence change falls in intron 1 of the TCOF1 gene. It does not directly change the encoded amino acid sequence of the TCOF1 protein. It affects a nucleotide within the consensus splice site of the intron. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.88		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.88		Position offset: 4

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr5-149740715;