2-135788386-G-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 3P and 4B. PM2 PP2 BP4_Strong

The NM_002299.4(LCT):c.5722C>A(p.Arg1908Ser) 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. 15/21 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. R1908C) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: LCT NM_002299.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.288

Genes affected

LCT (HGNC:6530): (lactase) The protein encoded by this gene belongs to the glycosyl hydrolase 1 family of proteins. The encoded preproprotein is proteolytically processed to generate the mature enzyme. This enzyme is integral to the plasma membrane and has both phlorizin hydrolase activity and lactase activity. Mutations in this gene are associated with congenital lactase deficiency. Polymorphisms in this gene are associated with lactase persistence, in which intestinal lactase activity persists at childhood levels into adulthood. [provided by RefSeq, Jan 2016]

ACMG classification

Verdict is Likely_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, LCT
• BP4: Computational evidence support a benign effect (MetaRNN=0.032621413).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LCT	NM_002299.4	c.5722C>A	p.Arg1908Ser	missense_variant	17/17	ENST00000264162.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LCT	ENST00000264162.7	c.5722C>A	p.Arg1908Ser	missense_variant	17/17	1	NM_002299.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

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

Jul 21, 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. 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 serine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. This variant has not been reported in the literature in individuals affected with LCT-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with serine, which is neutral and polar, at codon 1908 of the LCT protein (p.Arg1908Ser). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Benign	-0.29	T
BayesDel_noAF	Benign	-0.66
Cadd	Benign	0.59
Dann	Benign	0.54
DEOGEN2	Benign	0.27	T
Eigen	Benign	-1.5
Eigen_PC	Benign	-1.5
FATHMM_MKL	Benign	0.13	N
LIST_S2	Benign	0.20	T
M_CAP	Benign	0.0071	T
MetaRNN	Benign	0.033	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.4	L
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.20	T
PROVEAN	Benign	-0.37	N
REVEL	Benign	0.042
Sift	Benign	0.47	T
Sift4G	Benign	0.43	T
Polyphen		0.0	B
Vest4		0.10
MutPred		0.29		Loss of MoRF binding (P = 0.02);
MVP		0.085
MPC		0.70
ClinPred		0.037	T
GERP RS		0.60
Varity_R		0.13
gMVP		0.30

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-136545956;