chr19-42326320-G-T

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBS1_Supporting

The NM_001271938.2(MEGF8):​c.77G>T​(p.Arg26Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000708 in 1,566,852 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000074 ( 0 hom. )

Consequence

MEGF8
NM_001271938.2 missense

Scores

19

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: -0.863

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: Likely_benign. The variant received -5 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.017957658).
BS1
Variant frequency is greater than expected in population mid. GnomAdExome4 allele frequency = 0.0000735 (104/1414522) while in subpopulation MID AF = 0.00214 (12/5598). AF 95% confidence interval is 0.00124. There are 0 homozygotes in GnomAdExome4. There are 56 alleles in the male GnomAdExome4 subpopulation. Median coverage is 30. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MEGF8NM_001271938.2 linkc.77G>T p.Arg26Leu missense_variant Exon 1 of 42 ENST00000251268.11 NP_001258867.1 Q7Z7M0-1
MEGF8NM_001410.3 linkc.77G>T p.Arg26Leu missense_variant Exon 1 of 41 NP_001401.2 Q7Z7M0-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MEGF8ENST00000251268.11 linkc.77G>T p.Arg26Leu missense_variant Exon 1 of 42 5 NM_001271938.2 ENSP00000251268.5 Q7Z7M0-1
MEGF8ENST00000334370.8 linkc.77G>T p.Arg26Leu missense_variant Exon 1 of 41 1 ENSP00000334219.4 Q7Z7M0-2
MEGF8ENST00000378073.5 linkc.-7009G>T 5_prime_UTR_premature_start_codon_gain_variant Exon 1 of 41 5 ENSP00000367313.4 F5GZG7
MEGF8ENST00000378073.5 linkc.-7009G>T 5_prime_UTR_variant Exon 1 of 41 5 ENSP00000367313.4 F5GZG7

Frequencies

GnomAD3 genomes
AF:
0.0000657
AC:
10
AN:
152212
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000196
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.0127
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.000956
GnomAD2 exomes
AF:
0.0000808
AC:
16
AN:
198142
AF XY:
0.0000723
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000892
Gnomad ASJ exome
AF:
0.000123
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000127
Gnomad OTH exome
AF:
0.000223
GnomAD4 exome
AF:
0.0000735
AC:
104
AN:
1414522
Hom.:
0
Cov.:
30
AF XY:
0.0000796
AC XY:
56
AN XY:
703882
show subpopulations
African (AFR)
AF:
0.000135
AC:
4
AN:
29574
American (AMR)
AF:
0.000181
AC:
6
AN:
33082
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24416
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35808
South Asian (SAS)
AF:
0.00
AC:
0
AN:
80146
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52710
Middle Eastern (MID)
AF:
0.00214
AC:
12
AN:
5598
European-Non Finnish (NFE)
AF:
0.0000630
AC:
69
AN:
1094784
Other (OTH)
AF:
0.000223
AC:
13
AN:
58404
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.471
Heterozygous variant carriers
0
6
12
19
25
31
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000460
AC:
7
AN:
152330
Hom.:
0
Cov.:
32
AF XY:
0.0000940
AC XY:
7
AN XY:
74494
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41572
American (AMR)
AF:
0.000196
AC:
3
AN:
15298
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00340
AC:
1
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68032
Other (OTH)
AF:
0.000946
AC:
2
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
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:
0.000145
Hom.:
0
Bravo
AF:
0.0000756
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000121
AC:
1
ExAC
AF:
0.0000830
AC:
10
Asia WGS
AF:
0.000577
AC:
2
AN:
3478

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Jan 16, 2024
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

-
Breakthrough Genomics, Breakthrough Genomics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

Inborn genetic diseases Uncertain:1
Jun 06, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.77G>T (p.R26L) alteration is located in exon 1 (coding exon 1) of the MEGF8 gene. This alteration results from a G to T substitution at nucleotide position 77, causing the arginine (R) at amino acid position 26 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

MEGF8-related Carpenter syndrome Uncertain:1
Oct 21, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 26 of the MEGF8 protein (p.Arg26Leu). This variant is present in population databases (rs377001753, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with MEGF8-related conditions. ClinVar contains an entry for this variant (Variation ID: 1394338). 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. -

MEGF8-related disorder Uncertain:1
Dec 04, 2023
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The MEGF8 c.77G>T variant is predicted to result in the amino acid substitution p.Arg26Leu. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.013% of alleles in individuals of Latino descent in gnomAD (http://gnomad.broadinstitute.org/variant/19-42830472-G-T). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.070
BayesDel_addAF
Benign
-0.50
T
BayesDel_noAF
Benign
-0.74
CADD
Benign
0.049
DANN
Benign
0.91
DEOGEN2
Benign
0.096
.;T
Eigen
Benign
-1.8
Eigen_PC
Benign
-1.8
FATHMM_MKL
Benign
0.080
N
LIST_S2
Benign
0.66
T;T
M_CAP
Benign
0.0038
T
MetaRNN
Benign
0.018
T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
0.14
N;N
PhyloP100
-0.86
PrimateAI
Benign
0.32
T
PROVEAN
Benign
-0.99
N;N
REVEL
Benign
0.020
Sift
Benign
0.29
T;T
Sift4G
Benign
0.45
T;T
Polyphen
0.0
B;.
Vest4
0.043
MVP
0.068
MPC
0.48
ClinPred
0.032
T
GERP RS
-11
Varity_R
0.055
gMVP
0.13
Mutation Taster
=92/8
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: rs377001753; hg19: chr19-42830472; COSMIC: COSV52094266; COSMIC: COSV52094266; API