1-225937535-G-C

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_ModerateBS2

The NM_003240.5(LEFTY2):​c.1007C>G​(p.Thr336Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000335 in 1,613,896 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000034 ( 0 hom. )

Consequence

LEFTY2
NM_003240.5 missense

Scores

5
13

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 2.73

Publications

0 publications found
Variant links:
Genes affected
LEFTY2 (HGNC:3122): (left-right determination factor 2) This gene encodes a secreted ligand of the TGF-beta (transforming growth factor-beta) superfamily of proteins. Ligands of this family bind various TGF-beta receptors leading to recruitment and activation of SMAD family transcription factors that regulate gene expression. The encoded preproprotein is proteolytically processed to generate the mature protein, which plays a role in left-right asymmetry determination of organ systems during development. The protein may also play a role in endometrial bleeding. Mutations in this gene have been associated with left-right axis malformations, particularly in the heart and lungs. Some types of infertility have been associated with dysregulated expression of this gene in the endometrium. This gene is closely linked to both a related family member and a related pseudogene. This gene encodes multiple isoforms that may undergo similar proteolytic processing. [provided by RefSeq, Aug 2016]
LEFTY2 Gene-Disease associations (from GenCC):
  • visceral heterotaxy
    Inheritance: AD Classification: LIMITED Submitted by: G2P
  • congenital heart disease
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -6 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.14570099).
BS2
High AC in GnomAdExome4 at 50 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003240.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
LEFTY2
NM_003240.5
MANE Select
c.1007C>Gp.Thr336Ser
missense
Exon 4 of 4NP_003231.2
LEFTY2
NM_001172425.3
c.905C>Gp.Thr302Ser
missense
Exon 5 of 5NP_001165896.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
LEFTY2
ENST00000366820.10
TSL:1 MANE Select
c.1007C>Gp.Thr336Ser
missense
Exon 4 of 4ENSP00000355785.5
LEFTY2
ENST00000420304.6
TSL:2
c.905C>Gp.Thr302Ser
missense
Exon 5 of 5ENSP00000388009.2
ENSG00000248322
ENST00000513672.1
TSL:2
n.23C>G
non_coding_transcript_exon
Exon 1 of 2

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152194
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000398
AC:
10
AN:
251170
AF XY:
0.0000589
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000342
AC:
50
AN:
1461702
Hom.:
0
Cov.:
29
AF XY:
0.0000344
AC XY:
25
AN XY:
727146
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.000151
AC:
13
AN:
86248
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53400
Middle Eastern (MID)
AF:
0.000178
AC:
1
AN:
5630
European-Non Finnish (NFE)
AF:
0.0000297
AC:
33
AN:
1112012
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60378
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.466
Heterozygous variant carriers
0
4
8
11
15
19
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000263
AC:
4
AN:
152194
Hom.:
0
Cov.:
32
AF XY:
0.0000403
AC XY:
3
AN XY:
74350
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41446
American (AMR)
AF:
0.0000654
AC:
1
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.488
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000282
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.0000412
AC:
5
EpiCase
AF:
0.000109
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Jun 29, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1007C>G (p.T336S) alteration is located in exon 4 (coding exon 4) of the LEFTY2 gene. This alteration results from a C to G substitution at nucleotide position 1007, causing the threonine (T) at amino acid position 336 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear.

Left-right axis malformations Uncertain:1
Aug 05, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with serine, which is neutral and polar, at codon 336 of the LEFTY2 protein (p.Thr336Ser). This variant is present in population databases (rs749823804, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with LEFTY2-related conditions. ClinVar contains an entry for this variant (Variation ID: 406797). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.096
BayesDel_addAF
Benign
-0.37
T
BayesDel_noAF
Benign
-0.48
CADD
Benign
15
DANN
Uncertain
0.98
DEOGEN2
Uncertain
0.73
D
Eigen
Benign
-0.31
Eigen_PC
Benign
-0.29
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Benign
0.39
T
M_CAP
Benign
0.018
T
MetaRNN
Benign
0.15
T
MetaSVM
Benign
-0.82
T
MutationAssessor
Uncertain
2.3
M
PhyloP100
2.7
PrimateAI
Benign
0.29
T
PROVEAN
Uncertain
-2.4
N
REVEL
Benign
0.16
Sift
Benign
0.033
D
Sift4G
Benign
0.70
T
Polyphen
0.13
B
Vest4
0.096
MutPred
0.73
Gain of disorder (P = 0.048)
MVP
0.73
MPC
0.26
ClinPred
0.13
T
GERP RS
0.42
Varity_R
0.21
gMVP
0.67
Mutation Taster
=86/14
polymorphism

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

Other links and lift over

dbSNP: rs749823804; hg19: chr1-226125235; API