rs118204061

Positions:

chr8-19954240-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PP3_StrongPP5

The NM_000237.3(LPL):c.662T>C(p.Ile221Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000223 in 1,614,058 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

LPL
NM_000237.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:10U:1

Conservation

PhyloP100: 7.63

Variant links:

Genes affected

LPL (HGNC:6677): (lipoprotein lipase) LPL encodes lipoprotein lipase, which is expressed in heart, muscle, and adipose tissue. LPL functions as a homodimer, and has the dual functions of triglyceride hydrolase and ligand/bridging factor for receptor-mediated lipoprotein uptake. Severe mutations that cause LPL deficiency result in type I hyperlipoproteinemia, while less extreme mutations in LPL are linked to many disorders of lipoprotein metabolism. [provided by RefSeq, Jul 2008]

LPL links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.939

PP5

Variant 8-19954240-T-C is Pathogenic according to our data. Variant chr8-19954240-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1529.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Pathogenic=6, Uncertain_significance=1}. Variant chr8-19954240-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LPL	NM_000237.3 linkuse as main transcript	c.662T>C	p.Ile221Thr	missense_variant	5/10	ENST00000650287.1	NP_000228.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LPL	ENST00000650287.1 linkuse as main transcript	c.662T>C	p.Ile221Thr	missense_variant	5/10		NM_000237.3	ENSP00000497642	P1

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152174

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

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:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251462

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135904

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000205

AC:

AN:

1461884

Hom.:

Cov.:

AF XY:

0.0000220

AC XY:

AN XY:

727242

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000504

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000243

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152174

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74346

show subpopulations

Gnomad4 AFR

AF:

0.0000483

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000621

Hom.:

Bravo

AF:

0.0000340

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:10Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Hyperlipoproteinemia, type I

Pathogenic:4

Pathogenic, no assertion criteria provided	literature only	OMIM	Jun 01, 1991	- -
Pathogenic, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Apr 27, 2017	Across nine studies, the LPL c.662T>C (p.Ile221Thr) missense variant, which is also referred to as p.Ile194Thr, was identified in 18 subjects with familial lipoprotein lipase deficiency or severe hypertriglyceridemia, including four homozygotes, six compound heterozygotes, and eight heterozygotes in whom a second variant was not identified, and in a heterozygous state in at least two unaffected family members of patients (Henderson et al. 1991; Dichek et al. 1991; Santer et al. 2005; Nierman et al. 2006; Wang et al. 2007; Ooi et al. 2011; Rabacchi et al. 2015; Rodrigues et al. 2016; Tani et al. 2016). The variant was absent from 522 total control individuals in these studies. The variant is reported at a frequency of 0.00012 in the European American population of the Exome Sequencing Project, but this is based on only one allele in a region of good sequencing coverage so the variant is presumed to be rare in the general population. Functional studies demonstrated that despite finding the variant protein in the culture medium, the variant protein had virtually no lipolytic activity. Further, the amount of intracellular variant LPL protein was found to be higher than wildtype and it is suggested that the variant protein may not be secreted appropriately (Henderson et al. 1991). These results were confirmed in studies by Dichek et al. (1991) and Fojo et al. (1992). Based on the collective evidence, the p.Ile221Thr variant is classified as pathogenic for familial lipoprotein lipase deficiency. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Mar 17, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center	Apr 04, 2024	- -

not provided

Pathogenic:4

Likely pathogenic, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Dec 22, 2020	DNA sequence analysis of the LPL gene demonstrated a sequence change, c.662T>C, in exon 5 that results in an amino acid change, p.Ile221Thr. This sequence change has been described in the gnomAD database with a low overall population frequency of 0.002% and a frequency of 0.005% in east Asian sub group (dbSNP rs118204061). This sequence change has been described in individuals with hypertriglyceridemia in the heterozygous state (PMIDs: 21159338, 27055971, 17717288), and in individuals and family with lipoprotein ligase deficiency in the homozygous and compound heterozygous states (PMIDs: 1674945, 22095987, 16972177). The p.Ile221Thr change affects a highly conserved amino acid residue located in a domain of the lipoprotein lipase (LPL) that is known to be functional. Functional study shows p.Ile221Thr disrupts the enzyme activity of LPL (PMID: 1674945). Collectively these evidences indicate that the p.Ile221Thr variant is pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Clinical Genetics Laboratory, Skane University Hospital Lund	Jan 10, 2024	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 31, 2024	This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 221 of the LPL protein (p.Ile221Thr). This variant is present in population databases (rs118204061, gnomAD 0.005%). This missense change has been observed in individual(s) with clinical features of chylomicronemia (PMID: 1674945, 1702428, 15877202, 25966443). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is also known as p.Ile194Thr. ClinVar contains an entry for this variant (Variation ID: 1529). 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 expected to disrupt LPL protein function with a positive predictive value of 80%. Experimental studies have shown that this missense change affects LPL function (PMID: 1702428). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Apr 08, 2023	Published functional studies demonstrate that I221T results in defective LPL protein and inactive enzyme (Dichek et al., 1991; Henderson et al., 1991; Fojo et al., 1992; Peterson et al., 2002; Ooi et al., 2012; Wang et al., 2022); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Also known as I194T; This variant is associated with the following publications: (PMID: 17717288, 30389453, 1505655, 15877202, 16972177, 1702428, 27055971, 27573733, 25966443, 1479292, 11893776, 15256764, 31589614, 32041611, 1674945, 35923617, 22095987, 35820489) -

Hyperlipidemia, familial combined, LPL related

Pathogenic:1Uncertain:1

Uncertain significance, criteria provided, single submitter	curation	Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard	Jan 22, 2020	The p.Ile221Thr variant in LPL has been reported in at least 3 individuals (including South African, German, European origin) with familial combined hyperlipidemia, segregated with disease in 2 affected relatives from 1 family (PMID: 21159338, 17717288, 1674945), and has been identified in 0.005% (1/19954) of East Asian, 0.003% (3/129174) of European (non-Finnish), and 0.003% (1/35440) of Latino chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs118204061). This variant has also been reported in ClinVar as pathogenic (Variation ID: 1529). In vitro functional studies provide some evidence that the p.Ile221Thr variant may impact protein function (PMID: 1505655, 1674945, 11893776). However, these types of assays may not accurately represent biological function. Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. Three affected individuals with this variant have an alternative molecular basis for familial combined hyperlipidemia, suggesting that this variant may not be pathogenic (PMID: 16972177). In summary, the clinical significance of the p.Ile221Thr variant is uncertain. ACMG/AMP Criteria applied: PS4_supporting, PP3, BP5 (Richards 2015). -
Pathogenic, criteria provided, single submitter	clinical testing	Mendelics	May 04, 2022	- -

Cardiovascular phenotype

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 21, 2023

The p.I221T variant (also known as c.662T>C), located in coding exon 5 of the LPL gene, results from a T to C substitution at nucleotide position 662. The isoleucine at codon 221 is replaced by threonine, an amino acid with similar properties. This alteration has been reported as compound heterozygous with known pathogenic mutations in LPL and as homozygous in individuals with familial chylomicronemia syndrome (Dichek HL et al. J Biol Chem, 1991 Jan;266:473-7; Henderson HE et al. J Clin Invest, 1991 Jun;87:2005-11; Reina M et al. J Lipid Res, 1992 Dec;33:1823-32; Nierman MC et al. J Inherit Metab Dis, 2006 Oct;29:686; Ooi EM et al. Arterioscler Thromb Vasc Biol, 2012 Feb;32:459-66; Rabacchi C et al. Atherosclerosis, 2015 Jul;241:79-86). Additionally, this alteration has been reported as heterozygous in individuals with hypertriglyceridemia (Rodrigues R et al. J Clin Lipidol, 2016 Dec;10:394-409; Wang J et al. Arterioscler Thromb Vasc Biol, 2007 Nov;27:2450-5; Evans D et al. Atherosclerosis, 2011 Feb;214:386-90; Tada H et al. Clin Chim Acta, 2019 Jan;488:31-39). In vitro studies showed this alteration impacts protein function (Fojo SS et al. Eur J Epidemiol, 1992 May;8 Suppl 1:59-63; Peterson J et al. J Lipid Res, 2002 Mar;43:398-406). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.90

BayesDel_addAF

Pathogenic

0.35

BayesDel_noAF

Pathogenic

0.43

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.81

D;D

Eigen

Pathogenic

0.82

Eigen_PC

Pathogenic

0.80

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.94

.;D

M_CAP

Pathogenic

0.36

MetaRNN

Pathogenic

0.94

D;D

MetaSVM

Pathogenic

0.84

MutationAssessor

Uncertain

2.8

M;M

MutationTaster

Benign

1.0

PrimateAI

Pathogenic

0.83

PROVEAN

Pathogenic

-4.4

D;.

REVEL

Pathogenic

0.81

Sift

Uncertain

0.0010

D;.

Sift4G

Uncertain

0.0020

D;.

Polyphen

1.0

D;D

Vest4

0.96

MVP

0.99

MPC

0.49

ClinPred

0.96

GERP RS

6.2

Varity_R

0.93

gMVP

0.93

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

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