3-164979382-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001041.4(SI):c.5464A>G(p.Ile1822Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. I1822I) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SI NM_001041.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.322

Genes affected

SI (HGNC:10856): (sucrase-isomaltase) This gene encodes a sucrase-isomaltase enzyme that is expressed in the intestinal brush border. The encoded protein is synthesized as a precursor protein that is cleaved by pancreatic proteases into two enzymatic subunits sucrase and isomaltase. These two subunits heterodimerize to form the sucrose-isomaltase complex. This complex is essential for the digestion of dietary carbohydrates including starch, sucrose and isomaltose. Mutations in this gene are the cause of congenital sucrase-isomaltase deficiency.[provided by RefSeq, Apr 2010]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.18508902).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SI	NM_001041.4	c.5464A>G	p.Ile1822Val	missense_variant	48/48	ENST00000264382.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SI	ENST00000264382.8	c.5464A>G	p.Ile1822Val	missense_variant	48/48	1	NM_001041.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 26

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000284 Hom.: 0

Bravo AF: 0.00000756

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

Jun 13, 2022

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt SI protein function. This variant has not been reported in the literature in individuals affected with SI-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1822 of the SI protein (p.Ile1822Val). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.075
BayesDel_addAF	Benign	-0.059	T
BayesDel_noAF	Benign	-0.32
Cadd	Benign	5.3
Dann	Benign	0.62
DEOGEN2	Benign	0.023	T
Eigen	Benign	-0.77
Eigen_PC	Benign	-0.77
FATHMM_MKL	Benign	0.64	D
LIST_S2	Benign	0.59	T
M_CAP	Benign	0.037	D
MetaRNN	Benign	0.19	T
MetaSVM	Benign	-0.63	T
MutationAssessor	Uncertain	2.7	M
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.46	T
PROVEAN	Benign	0.050	N
REVEL	Uncertain	0.33
Sift	Benign	0.44	T
Sift4G	Benign	0.44	T
Polyphen		0.077	B
Vest4		0.25
MutPred		0.58		Gain of sheet (P = 0.0344);
MVP		0.67
MPC		0.026
ClinPred		0.16	T
GERP RS		0.28
Varity_R		0.031
gMVP		0.33

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

Publications

LitVar

Other links and lift over

dbSNP: rs965822078; hg19: chr3-164697170;