21-33546256-A-G

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_Strong BS1_Supporting BS2

The NM_138927.4(SON):c.121A>G(p.Ile41Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000229 in 1,613,962 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000046 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000021 (0 hom.)
• Consequence: SON NM_138927.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.465

Genes affected

SON (HGNC:11183): (SON DNA and RNA binding protein) This gene encodes a protein that contains multiple simple repeats. The encoded protein binds RNA and promotes pre-mRNA splicing, particularly of transcripts with poor splice sites. The protein also recognizes a specific DNA sequence found in the human hepatitis B virus (HBV) and represses HBV core promoter activity. There is a pseudogene for this gene on chromosome 1. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2013]

ACMG classification

Verdict is Benign. Variant got -9 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.006085366).
• BS1: Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.0000459 (7/152346) while in subpopulation AMR AF= 0.000392 (6/15310). AF 95% confidence interval is 0.00017. There are 0 homozygotes in gnomad4. There are 1 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High AC in GnomAd at 7 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SON	NM_138927.4	c.121A>G	p.Ile41Val	missense_variant	2/12	ENST00000356577.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SON	ENST00000356577.10	c.121A>G	p.Ile41Val	missense_variant	2/12	1	NM_138927.4	P3

Frequencies

GnomAD3 genomes AF: 0.0000460 AC: 7 AN: 152228 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000392

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: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000876 AC: 22 AN: 251264 Hom.: 0 AF XY: 0.0000810 AC XY: 11 AN XY: 135820

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000406

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00131

GnomAD4 exome AF: 0.0000205 AC: 30 AN: 1461616 Hom.: 0 Cov.: 30 AF XY: 0.0000234 AC XY: 17 AN XY: 727106

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000470

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.000116

GnomAD4 genome AF: 0.0000459 AC: 7 AN: 152346 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74502

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.000392

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000422 Hom.: 0

Bravo AF: 0.0000604

ExAC AF: 0.0000741 AC: 9

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 27, 2024

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 41 of the SON protein (p.Ile41Val). This variant is present in population databases (rs202224123, gnomAD 0.04%), and has an allele count higher than expected for a pathogenic variant. This variant has not been reported in the literature in individuals affected with SON-related conditions. ClinVar contains an entry for this variant (Variation ID: 2169852). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.065
BayesDel_addAF	Benign	-0.54	T
BayesDel_noAF	Benign	-0.69
Cadd	Benign	7.8
Dann	Benign	0.41
DEOGEN2	Benign	0.0095	T;.;.;.
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.12	N
LIST_S2	Benign	0.66	T;T;T;T
M_CAP	Benign	0.012	T
MetaRNN	Benign	0.0061	T;T;T;T
MetaSVM	Benign	-0.93	T
MutationAssessor	Benign	0.14	N;.;N;N
MutationTaster	Benign	1.0	N;N;N;N;N
PrimateAI	Benign	0.26	T
PROVEAN	Benign	-0.12	N;N;N;N
REVEL	Benign	0.039
Sift	Benign	0.40	T;D;T;T
Sift4G	Benign	0.75	T;T;T;T
Polyphen		0.035	B;.;B;B
Vest4		0.11
MVP		0.11
MPC		0.079
ClinPred		0.018	T
GERP RS		-6.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.030
gMVP		0.17

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs202224123; hg19: chr21-34918562;