NM_006918.5:c.17G>C

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_006918.5(SC5D):​c.17G>C​(p.Arg6Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,772 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. R6C) has been classified as Benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SC5D
NM_006918.5 missense

Scores

1
3
15

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.746

Publications

0 publications found
Variant links:
Genes affected
SC5D (HGNC:10547): (sterol-C5-desaturase) This gene encodes an enzyme of cholesterol biosynthesis. The encoded protein catalyzes the conversion of lathosterol into 7-dehydrocholesterol. Mutations in this gene have been associated with lathosterolosis. Alternatively spliced transcript variants encoding the same protein have been described. [provided by RefSeq, Jul 2008]
SC5D Gene-Disease associations (from GenCC):
  • lathosterolosis
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SC5DNM_006918.5 linkc.17G>C p.Arg6Pro missense_variant Exon 2 of 5 ENST00000264027.9 NP_008849.2 O75845A0A024R3G4
SC5DNM_001024956.3 linkc.17G>C p.Arg6Pro missense_variant Exon 2 of 5 NP_001020127.1 O75845A0A024R3G4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SC5DENST00000264027.9 linkc.17G>C p.Arg6Pro missense_variant Exon 2 of 5 1 NM_006918.5 ENSP00000264027.4 O75845

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152118
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461654
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
727154
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39682
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53404
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111826
Other (OTH)
AF:
0.00
AC:
0
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152118
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74306
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000241
AC:
1
AN:
41412
American (AMR)
AF:
0.00
AC:
0
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10600
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68022
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not provided Uncertain:1
Jul 17, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 1943675). This variant has not been reported in the literature in individuals affected with SC5D-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 6 of the SC5D protein (p.Arg6Pro). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.67
BayesDel_addAF
Uncertain
0.092
D
BayesDel_noAF
Benign
-0.11
CADD
Benign
11
DANN
Benign
0.95
DEOGEN2
Benign
0.28
T;T;T;T
Eigen
Benign
-1.1
Eigen_PC
Benign
-1.0
FATHMM_MKL
Benign
0.26
N
LIST_S2
Benign
0.79
.;T;T;T
M_CAP
Uncertain
0.096
D
MetaRNN
Benign
0.15
T;T;T;T
MetaSVM
Benign
-0.77
T
MutationAssessor
Benign
0.0
N;.;.;N
PhyloP100
0.75
PrimateAI
Benign
0.34
T
PROVEAN
Benign
0.020
N;N;N;N
REVEL
Uncertain
0.48
Sift
Benign
0.030
D;T;T;D
Sift4G
Benign
0.097
T;T;T;T
Polyphen
0.018
B;B;B;B
Vest4
0.091
MVP
0.61
MPC
0.19
ClinPred
0.40
T
GERP RS
-0.91
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.14
gMVP
0.85
Mutation Taster
=99/1
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.22
Details are displayed if max score is > 0.2
DS_AL_spliceai
0.22
Position offset: -26

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs370681255; hg19: chr11-121174101; API