2-135800639-C-A

Position:

• chr2-135800639-C-A

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_002299.4(LCT):​c.4834G>T​(p.Glu1612Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (no stars). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 31)
• Consequence: LCT NM_002299.4 stop_gained
• Clinical Significance: Likely pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 2.78

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 Pathogenic. Variant got 11 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-135800639-C-A is Pathogenic according to our data. Variant chr2-135800639-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 56390.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr2-135800639-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LCT	NM_002299.4	c.4834G>T	p.Glu1612Ter	stop_gained	12/17	ENST00000264162.7	NP_002290.2
LCT	XM_017004088.3	c.4834G>T	p.Glu1612Ter	stop_gained	12/15		XP_016859577.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LCT	ENST00000264162.7	c.4834G>T	p.Glu1612Ter	stop_gained	12/17	1	NM_002299.4	ENSP00000264162	P1
LCT	ENST00000452974.1	c.2960-2501G>T		intron_variant, NMD_transcript_variant		1		ENSP00000391231

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Congenital lactase deficiency Pathogenic:1

Likely pathogenic, no assertion criteria provided

literature only

Juha Muilu Group; Institute for Molecular Medicine Finland (FIMM)

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.63
CADD	Pathogenic	40
DANN	Uncertain	1.0
Eigen	Pathogenic	0.79
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Uncertain	0.97	D
MutationTaster	Benign	1.0	A
Vest4		0.78
GERP RS		2.8

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs386833835; hg19: chr2-136558209;