19-42334083-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_001271938.2(MEGF8):​c.428C>T​(p.Pro143Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000868 in 1,613,418 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P143Q) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

MEGF8
NM_001271938.2 missense

Scores

1
4
14

Clinical Significance

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

Conservation

PhyloP100: 2.59

Publications

0 publications found
Variant links:
Genes affected
MEGF8 (HGNC:3233): (multiple EGF like domains 8) The protein encoded by this gene is a single-pass type I membrane protein of unknown function that contains several EGF-like domains, Kelch repeats, and PSI domains. Defects in this gene are a cause of Carpenter syndrome 2. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2012]
MEGF8 Gene-Disease associations (from GenCC):
  • MEGF8-related Carpenter syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: PanelApp Australia, G2P, Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae)
  • Carpenter syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.17709771).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MEGF8NM_001271938.2 linkc.428C>T p.Pro143Leu missense_variant Exon 3 of 42 ENST00000251268.11 NP_001258867.1 Q7Z7M0-1
MEGF8NM_001410.3 linkc.428C>T p.Pro143Leu missense_variant Exon 3 of 41 NP_001401.2 Q7Z7M0-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MEGF8ENST00000251268.11 linkc.428C>T p.Pro143Leu missense_variant Exon 3 of 42 5 NM_001271938.2 ENSP00000251268.5 Q7Z7M0-1
MEGF8ENST00000334370.8 linkc.428C>T p.Pro143Leu missense_variant Exon 3 of 41 1 ENSP00000334219.4 Q7Z7M0-2
MEGF8ENST00000378073.5 linkc.-6658C>T 5_prime_UTR_premature_start_codon_gain_variant Exon 3 of 41 5 ENSP00000367313.4 F5GZG7
MEGF8ENST00000378073.5 linkc.-6658C>T 5_prime_UTR_variant Exon 3 of 41 5 ENSP00000367313.4 F5GZG7

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152150
Hom.:
0
Cov.:
32
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:
0.0000943
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000403
AC:
1
AN:
247972
AF XY:
0.00000742
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000290
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000890
AC:
13
AN:
1461268
Hom.:
0
Cov.:
32
AF XY:
0.00000825
AC XY:
6
AN XY:
726950
show subpopulations
African (AFR)
AF:
0.0000597
AC:
2
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44704
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26120
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86248
European-Finnish (FIN)
AF:
0.0000188
AC:
1
AN:
53076
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000270
AC:
3
AN:
1111814
Other (OTH)
AF:
0.0000994
AC:
6
AN:
60360
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.479
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.00000657
AC:
1
AN:
152150
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74320
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41438
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.0000943
AC:
1
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.225
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.00000827
AC:
1
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

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

Submissions by phenotype

MEGF8-related Carpenter syndrome Uncertain:1
Aug 26, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces proline with leucine at codon 143 of the MEGF8 protein (p.Pro143Leu). The proline residue is weakly conserved and there is a moderate physicochemical difference between proline and leucine. This variant is present in population databases (rs765654107, ExAC 0.009%). This variant has not been reported in the literature in individuals affected with MEGF8-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The leucine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -

Inborn genetic diseases Uncertain:1
Sep 26, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.428C>T (p.P143L) alteration is located in exon 3 (coding exon 3) of the MEGF8 gene. This alteration results from a C to T substitution at nucleotide position 428, causing the proline (P) at amino acid position 143 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.17
BayesDel_addAF
Benign
-0.32
T
BayesDel_noAF
Benign
-0.62
CADD
Benign
22
DANN
Benign
0.93
DEOGEN2
Uncertain
0.54
.;D
Eigen
Benign
-0.23
Eigen_PC
Benign
-0.15
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.85
D;D
M_CAP
Benign
0.037
D
MetaRNN
Benign
0.18
T;T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
1.7
L;L
PhyloP100
2.6
PrimateAI
Uncertain
0.54
T
PROVEAN
Pathogenic
-4.8
D;D
REVEL
Benign
0.12
Sift
Benign
0.28
T;T
Sift4G
Uncertain
0.0050
D;D
Polyphen
0.0
B;.
Vest4
0.42
MutPred
0.48
Loss of disorder (P = 0.0273);Loss of disorder (P = 0.0273);
MVP
0.068
MPC
0.39
ClinPred
0.20
T
GERP RS
3.8
Varity_R
0.14
gMVP
0.64
Mutation Taster
=45/55
disease causing

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: rs765654107; hg19: chr19-42838235; API