3-3151023-A-C

Variant names:

• chr3-3151023-A-C
• rs797045036
• NM_016302.4:c.1171T>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PM5 PP3_Moderate

The NM_016302.4(CRBN):​c.1171T>G​(p.Cys391Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,620 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C391R) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CRBN NM_016302.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.11
• Publications: 0 publications found

Genes affected

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]

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]

TRNT1 Gene-Disease associations (from GenCC):

• congenital sideroblastic anemia-B-cell immunodeficiency-periodic fever-developmental delay syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), ClinGen
• retinitis pigmentosa and erythrocytic microcytosis

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

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-3151023-A-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 209144.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.916

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRBN	NM_016302.4	c.1171T>G	p.Cys391Gly	missense_variant	Exon 11 of 11	ENST00000231948.9	NP_057386.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRBN	ENST00000231948.9	c.1171T>G	p.Cys391Gly	missense_variant	Exon 11 of 11	1	NM_016302.4	ENSP00000231948.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461620 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727120

⚠️ 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: 33470

American (AMR) AF: 0.0000224 AC: 1 AN: 44658

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26124

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53386

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111900

Other (OTH) AF: 0.00 AC: 0 AN: 60372

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000203476), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.46
CADD	Pathogenic	31
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.57	.;D;.
Eigen	Uncertain	0.54
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.91	D;D;D
M_CAP	Uncertain	0.26	D
MetaRNN	Pathogenic	0.92	D;D;D
MetaSVM	Uncertain	0.22	D
MutationAssessor	Pathogenic	3.7	.;H;.
PhyloP100		9.1
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-11	.;D;D
REVEL	Uncertain	0.60
Sift	Pathogenic	0.0	.;D;D
Sift4G	Pathogenic	0.0	.;D;D
Polyphen		0.0010	.;B;B
Vest4		0.97, 0.97
MutPred		0.71		Loss of methylation at K392 (P = 0.0294);Loss of methylation at K392 (P = 0.0294);.;
MVP		0.85
MPC		0.52
ClinPred		1.0	D
GERP RS		4.4
Varity_R		0.98
gMVP		0.98
Mutation Taster		=11/89	disease causing

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: rs797045036; hg19: chr3-3192707;