rs876661299

Variant names:

• chr3-3146404-T-C
• rs876661299
• NM_182916.3:c.609-26T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 8P and 1B. PS3 PM2 PP5_Moderate BP4

The NM_182916.3(TRNT1):​c.609-26T>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000279 in 1,431,606 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 Pathogenic (★). ClinVar reports functional evidence for this variant: "SCV002234131: Studies have shown that this variant is associated with altered splicing resulting in unknown protein product impact (PMID:26494905).". There are indicators that this mutation may affect the branch point..

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000028 (0 hom.)
• Consequence: TRNT1 NM_182916.3 intron
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 0.429
• Publications: 1 publications found

Genes affected

TRNT1 (HGNC:17341): (tRNA nucleotidyl transferase 1) The protein encoded by this gene is a CCA-adding enzyme which belongs to the tRNA nucleotidyltransferase/poly(A) polymerase family. This essential enzyme functions by catalyzing the addition of the conserved nucleotide triplet CCA to the 3' terminus of tRNA molecules. Mutations in this gene result in sideroblastic anemia with B-cell immunodeficiency, periodic fevers, and developmental delay. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Dec 2014]

CRBN (HGNC:30185): (cereblon) This gene encodes a protein related to the Lon protease protein family. In rodents and other mammals this gene product is found in the cytoplasm localized with a calcium channel membrane protein, and is thought to play a role in brain development. Mutations in this gene are associated with autosomal recessive nonsyndromic cognitive disability. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Mar 2010]

CRBN Gene-Disease associations (from GenCC):

• intellectual disability

  Inheritance: AR Classification: MODERATE Submitted by: ClinGen
• autosomal recessive non-syndromic intellectual disability

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• intellectual disability, autosomal recessive 2

  Inheritance: AR Classification: LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV002234131: Studies have shown that this variant is associated with altered splicing resulting in unknown protein product impact (PMID: 26494905).
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 3-3146404-T-C is Pathogenic according to our data. Variant chr3-3146404-T-C is described in ClinVar as Pathogenic. ClinVar VariationId is 234935.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP4: This position, referring to a specific DNA site, is a probable branch point but is likely benign (scored 1 / 10, using the threshold of <=3). The score ranges from 0 to 10, with values ≤3 considered benign and >5 classified as pathogenic. Computational evidence support a benign effect (BayesDel_noAF=-0.84). . Strength limited to SUPPORTING due to the PP5.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_182916.3. 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
	TRNT1	NM_182916.3	MANE Select	c.609-26T>C		intron	N/A	NP_886552.3	Q96Q11-1
	TRNT1	NM_001367321.1		c.609-26T>C		intron	N/A	NP_001354250.1	Q96Q11-1
	TRNT1	NM_001367322.1		c.609-26T>C		intron	N/A	NP_001354251.1	Q96Q11-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TRNT1	ENST00000251607.11	TSL:1 MANE Select	c.609-26T>C		intron	N/A	ENSP00000251607.6	Q96Q11-1
	TRNT1	ENST00000280591.10	TSL:1	c.609-26T>C		intron	N/A	ENSP00000280591.6	Q96Q11-2
	CRBN	ENST00000639284.1	TSL:5	c.1312-905A>G		intron	N/A	ENSP00000491442.1	A0A1W2PPJ5

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD2 exomes AF: 0.00000851 AC: 2 AN: 234992 AF XY: 0.0000158

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: 0.00000929

Gnomad OTH exome AF: 0.000177

GnomAD4 exome AF: 0.00000279 AC: 4 AN: 1431606 Hom.: 0 Cov.: 28 AF XY: 0.00000562 AC XY: 4 AN XY: 712308

African (AFR) AF: 0.00 AC: 0 AN: 32218

American (AMR) AF: 0.00 AC: 0 AN: 41284

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24698

East Asian (EAS) AF: 0.00 AC: 0 AN: 39526

South Asian (SAS) AF: 0.00 AC: 0 AN: 82436

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52644

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5614

European-Non Finnish (NFE) AF: 0.00000183 AC: 2 AN: 1094060

Other (OTH) AF: 0.0000338 AC: 2 AN: 59126

GnomAD4 genome Cov.: 31

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	Congenital sideroblastic anemia-B-cell immunodeficiency-periodic fever-developmental delay syndrome (1)
1	-	-	Retinitis pigmentosa and erythrocytic microcytosis (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.84
CADD	Benign	7.8
DANN	Benign	0.69
PhyloP100		0.43
BranchPoint Hunter		1.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Mutation Taster		=41/59	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs876661299; hg19: chr3-3188088;