rs121908936

Variant names:

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 10P and 1B. PVS1PP5_ModerateBS2_Supporting

The NM_002299.4(LCT):c.4170T>A(p.Tyr1390*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000311 in 1,613,974 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.00069 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00027 ( 2 hom. )

Consequence

LCT
NM_002299.4 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, single submitter P:3

Conservation

PhyloP100: 1.60

Variant links:

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]

LCT links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PP5

Variant 2-135807131-A-T is Pathogenic according to our data. Variant chr2-135807131-A-T is described in ClinVar as [Pathogenic]. Clinvar id is 6586.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr2-135807131-A-T is described in Lovd as [Pathogenic].

BS2

High Homozygotes in GnomAdExome4 at 2 AR geneVariant has number of homozygotes lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LCT	NM_002299.4 link	c.4170T>A	p.Tyr1390*	stop_gained	Exon 9 of 17	ENST00000264162.7	NP_002290.2	P09848
LCT	XM_017004088.3 link	c.4170T>A	p.Tyr1390*	stop_gained	Exon 9 of 15		XP_016859577.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LCT	ENST00000264162.7 link	c.4170T>A	p.Tyr1390*	stop_gained	Exon 9 of 17	1	NM_002299.4	ENSP00000264162.2		P09848
LCT	ENST00000452974.1 link	n.2466T>A		non_coding_transcript_exon_variant	Exon 3 of 7	1		ENSP00000391231.1		H0Y4E4

Frequencies

GnomAD3 genomes

AF:

0.000690

AC:

105

AN:

152146

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00980

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000872

AC:

219

AN:

251102

Hom.:

AF XY:

0.000913

AC XY:

124

AN XY:

135774

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00984

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.000652

GnomAD4 exome

AF:

0.000272

AC:

397

AN:

1461828

Hom.:

Cov.:

AF XY:

0.000287

AC XY:

209

AN XY:

727220

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00732

Gnomad4 NFE exome

AF:

0.00000180

Gnomad4 OTH exome

AF:

0.0000662

GnomAD4 genome

AF:

0.000690

AC:

105

AN:

152146

Hom.:

Cov.:

AF XY:

0.00116

AC XY:

AN XY:

74310

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00980

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.00000988

Hom.:

Bravo

AF:

0.0000151

ExAC

AF:

0.000494

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Congenital lactase deficiency

Pathogenic:2

Jan 06, 2020

Reproductive Health Research and Development, BGI Genomics

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: curation

NM_002299.2:c.4170T>A in the LCT gene has an allele frequency of 0.01 in European (Finnish) subpopulation in the gnomAD database. Twenty-seven patients out of 32 (84%) affected with congenital lactase deficiency were homozygous for this nonsense mutation, c.4170T>A (p.Y1390X) (PMID: 16400612). This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. Taken together, we interprete this variant as Pathogenic/Likely pathogenic. ACMG/AMP Criteria applied: PVS1; PS4. -

Feb 01, 2006

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

not provided

Pathogenic:1

Nov 03, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Tyr1390*) in the LCT gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in LCT are known to be pathogenic (PMID: 16400612, 25881162). This variant is present in population databases (rs121908936, gnomAD 0.9%), including at least one homozygous and/or hemizygous individual. This premature translational stop signal has been observed in individual(s) with congenital lactase deficiency (PMID: 16400612). ClinVar contains an entry for this variant (Variation ID: 6586). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.61

BayesDel_noAF

Pathogenic

0.58

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Uncertain

0.47

Eigen_PC

Uncertain

0.29

FATHMM_MKL

Uncertain

0.92

Vest4

0.95

GERP RS

0.86

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over