3-167789160-T-C

Variant names:

• chr3-167789160-T-C
• NM_001122752.2:c.32T>C

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001122752.2(SERPINI1):​c.32T>C​(p.Val11Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,772 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V11I) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: SERPINI1 NM_001122752.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.88
• Publications: 0 publications found

Genes affected

SERPINI1 (HGNC:8943): (serpin family I member 1) This gene encodes a member of the serpin superfamily of serine proteinase inhibitors. The protein is primarily secreted by axons in the brain, and preferentially reacts with and inhibits tissue-type plasminogen activator. It is thought to play a role in the regulation of axonal growth and the development of synaptic plasticity. Mutations in this gene result in familial encephalopathy with neuroserpin inclusion bodies (FENIB), which is a dominantly inherited form of familial encephalopathy and epilepsy characterized by the accumulation of mutant neuroserpin polymers. Multiple alternatively spliced variants, encoding the same protein, have been identified. [provided by RefSeq, Jul 2008]

SERPINI1 Gene-Disease associations (from GenCC):

• progressive myoclonus epilepsy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• familial encephalopathy with neuroserpin inclusion bodies

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.13227391).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SERPINI1	NM_001122752.2	c.32T>C	p.Val11Ala	missense_variant	Exon 2 of 9	ENST00000446050.7	NP_001116224.1
SERPINI1	NM_005025.5	c.32T>C	p.Val11Ala	missense_variant	Exon 2 of 9		NP_005016.1
SERPINI1	XM_017006618.3	c.32T>C	p.Val11Ala	missense_variant	Exon 2 of 9		XP_016862107.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SERPINI1	ENST00000446050.7	c.32T>C	p.Val11Ala	missense_variant	Exon 2 of 9	1	NM_001122752.2	ENSP00000397373.2
SERPINI1	ENST00000295777.9	c.32T>C	p.Val11Ala	missense_variant	Exon 2 of 9	1		ENSP00000295777.5
SERPINI1	ENST00000472747.2	c.32T>C	p.Val11Ala	missense_variant	Exon 2 of 5	3		ENSP00000420561.2
SERPINI1	ENST00000472941.5	c.32T>C	p.Val11Ala	missense_variant	Exon 2 of 3	3		ENSP00000420133.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461772 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727184

⚠️ 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: 33480

American (AMR) AF: 0.0000224 AC: 1 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53378

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111958

Other (OTH) AF: 0.00 AC: 0 AN: 60392

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Familial encephalopathy with neuroserpin inclusion bodies Uncertain:1

Dec 16, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces valine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 11 of the SERPINI1 protein (p.Val11Ala). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SERPINI1-related conditions. ClinVar contains an entry for this variant (Variation ID: 2156345). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt SERPINI1 protein function with a negative predictive value of 95%. 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	0.10
BayesDel_addAF	Benign	-0.036	T
BayesDel_noAF	Benign	-0.29
CADD	Benign	15
DANN	Benign	0.72
DEOGEN2	Benign	0.014	T;T;T;T
Eigen	Benign	-0.62
Eigen_PC	Benign	-0.47
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Benign	0.38	T;.;T;T
M_CAP	Benign	0.040	D
MetaRNN	Benign	0.13	T;T;T;T
MetaSVM	Benign	-0.86	T
MutationAssessor	Benign	0.46	.;N;N;.
PhyloP100		3.9
PrimateAI	Benign	0.33	T
PROVEAN	Benign	-0.080	N;N;N;N
REVEL	Benign	0.23
Sift	Benign	0.22	T;T;T;T
Sift4G	Benign	0.33	T;T;T;T
Polyphen		0.0	.;B;B;.
Vest4		0.072, 0.071
MutPred		0.52		Loss of stability (P = 0.0077);Loss of stability (P = 0.0077);Loss of stability (P = 0.0077);Loss of stability (P = 0.0077);
MVP		0.42
MPC		0.11
ClinPred		0.30	T
GERP RS		2.9
Varity_R		0.026
gMVP		0.35
Mutation Taster		=88/12	polymorphism

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

hg19: chr3-167506948;