rs121908936

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 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

Publications

10 publications found

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 Gene-Disease associations (from GenCC):

congenital lactase deficiency
Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), PanelApp Australia, Ambry Genetics

LCT links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 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 VariationId is 6586.Status of the report is criteria_provided_single_submitter, 1 stars.

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
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
LCT	ENST00000452974.1 link	n.2466T>A		non_coding_transcript_exon_variant	Exon 3 of 7	1		ENSP00000391231.1

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

GnomAD2 exomes

AF:

0.000872

AC:

219

AN:

251102

AF XY:

0.000913

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 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

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86240

European-Finnish (FIN)

AF:

0.00732

AC:

391

AN:

53418

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1111970

Other (OTH)

AF:

0.0000662

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.485

Heterozygous variant carriers

119

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000690

AC:

105

AN:

152146

Hom.:

Cov.:

AF XY:

0.00116

AC XY:

AN XY:

74310

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41432

American (AMR)

AF:

0.00

AC:

AN:

15284

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3466

East Asian (EAS)

AF:

0.00

AC:

AN:

5190

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00980

AC:

104

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68014

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.506

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

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

(source)

DANN

Uncertain

1.0

Eigen

Uncertain

0.47

Eigen_PC

Uncertain

0.29

FATHMM_MKL

Uncertain

0.92

PhyloP100

1.6

Vest4

0.95

GERP RS

0.86

Mutation Taster

=9/191

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over