rs148609143

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_001360.3(DHCR7):​c.719A>G​(p.Asn240Ser) variant causes a missense change. The variant allele was found at a frequency of 0.000247 in 1,614,108 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 Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00018 ( 0 hom., cov: 34)
Exomes 𝑓: 0.00025 ( 0 hom. )

Consequence

DHCR7
NM_001360.3 missense

Scores

7
10
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:12

Conservation

PhyloP100: 6.89
Variant links:
Genes affected
DHCR7 (HGNC:2860): (7-dehydrocholesterol reductase) This gene encodes an enzyme that removes the C(7-8) double bond in the B ring of sterols and catalyzes the conversion of 7-dehydrocholesterol to cholesterol. This gene is ubiquitously expressed and its transmembrane protein localizes to the endoplasmic reticulum membrane and nuclear outer membrane. Mutations in this gene cause Smith-Lemli-Opitz syndrome (SLOS); a syndrome that is metabolically characterized by reduced serum cholesterol levels and elevated serum 7-dehydrocholesterol levels and phenotypically characterized by cognitive disability, facial dysmorphism, syndactyly of second and third toes, and holoprosencephaly in severe cases to minimal physical abnormalities and near-normal intelligence in mild cases. Alternative splicing results in multiple transcript variants that encode the same protein.[provided by RefSeq, Aug 2009]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.868

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
DHCR7NM_001360.3 linkc.719A>G p.Asn240Ser missense_variant Exon 7 of 9 ENST00000355527.8 NP_001351.2 Q9UBM7A0A024R5F7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
DHCR7ENST00000355527.8 linkc.719A>G p.Asn240Ser missense_variant Exon 7 of 9 1 NM_001360.3 ENSP00000347717.4 Q9UBM7
DHCR7ENST00000685320.1 linkc.134A>G p.Asn45Ser missense_variant Exon 6 of 8 ENSP00000509319.1 B4E1K5

Frequencies

GnomAD3 genomes
AF:
0.000184
AC:
28
AN:
152232
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.000121
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000386
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000265
Gnomad OTH
AF:
0.000478
GnomAD3 exomes
AF:
0.000159
AC:
40
AN:
251374
Hom.:
0
AF XY:
0.000140
AC XY:
19
AN XY:
135908
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000116
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000308
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.000254
AC:
371
AN:
1461758
Hom.:
0
Cov.:
33
AF XY:
0.000260
AC XY:
189
AN XY:
727166
show subpopulations
Gnomad4 AFR exome
AF:
0.0000896
Gnomad4 AMR exome
AF:
0.0000894
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:
0.000308
Gnomad4 OTH exome
AF:
0.000331
GnomAD4 genome
AF:
0.000184
AC:
28
AN:
152350
Hom.:
0
Cov.:
34
AF XY:
0.000228
AC XY:
17
AN XY:
74502
show subpopulations
Gnomad4 AFR
AF:
0.000120
Gnomad4 AMR
AF:
0.000131
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.000387
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000265
Gnomad4 OTH
AF:
0.000473
Alfa
AF:
0.000273
Hom.:
0
Bravo
AF:
0.000193
TwinsUK
AF:
0.000809
AC:
3
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000582
AC:
5
ExAC
AF:
0.000157
AC:
19
EpiCase
AF:
0.0000545
EpiControl
AF:
0.000296

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:12
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:5
Jan 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

DHCR7: PP3 -

Jun 14, 2018
Eurofins Ntd Llc (ga)
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Dec 30, 2023
GeneDx
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 23603282, 24813812) -

May 08, 2017
Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Aug 09, 2021
Greenwood Genetic Center Diagnostic Laboratories, Greenwood Genetic Center
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

PP3, PM2 -

Smith-Lemli-Opitz syndrome Uncertain:4
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jun 03, 2022
Revvity Omics, Revvity
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

May 11, 2018
Natera, Inc.
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Jun 20, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 240 of the DHCR7 protein (p.Asn240Ser). This variant is present in population databases (rs148609143, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with DHCR7-related conditions. ClinVar contains an entry for this variant (Variation ID: 445437). 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 DHCR7 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. -

not specified Uncertain:1
Jun 03, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: DHCR7 c.719A>G (p.Asn240Ser) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00016 in 251374 control chromosomes (gnomAD). This frequency is not significantly higher than expected for a pathogenic variant in DHCR7 causing Smith-Lemli-Opitz Syndrome (0.00016 vs 0.0043), allowing no conclusion about variant significance. c.719A>G has been reported in the literature in one individual affected with Cardiac defect (Hauser_2018). The report does not provide unequivocal conclusions about association of the variant with Smith-Lemli-Opitz Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Eight ClinVar submitters (evaluation after 2014) cite the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Inborn genetic diseases Uncertain:1
Jan 24, 2018
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.N240S variant (also known as c.719A>G), located in coding exon 5 of the DHCR7 gene, results from an A to G substitution at nucleotide position 719. The asparagine at codon 240 is replaced by serine, an amino acid with highly similar properties. In one study that aimed to determine the allele carrier frequency of Smith-Lemli-Opitz syndrome (SLOS), this variant was identified in the ESP population database cohort (Cross JL et al. Clin. Genet., 2015 Jun;87:570-5). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this variant remains unclear. -

DHCR7-related disorder Uncertain:1
May 09, 2024
PreventionGenetics, part of Exact Sciences
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

The DHCR7 c.719A>G variant is predicted to result in the amino acid substitution p.Asn240Ser. This variant has been reported in a carrier study of the DHCR7 gene (Cross et al. 2015. PubMed ID: 24813812); however, to our knowledge, this variant has not been reported in individuals with Smith-Lemli-Opitz syndrome. This variant is reported in 0.029% of alleles in individuals of European (Non-Finnish) descent in gnomAD. 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
Uncertain
0.44
BayesDel_addAF
Benign
-0.0089
T
BayesDel_noAF
Uncertain
0.050
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.99
D;D;D;.
Eigen
Uncertain
0.67
Eigen_PC
Uncertain
0.59
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.97
.;D;D;D
M_CAP
Pathogenic
0.32
D
MetaRNN
Pathogenic
0.87
D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
2.9
M;M;.;.
PrimateAI
Uncertain
0.73
T
PROVEAN
Uncertain
-4.2
D;D;D;D
REVEL
Pathogenic
0.83
Sift
Uncertain
0.012
D;D;T;D
Sift4G
Uncertain
0.047
D;D;D;.
Polyphen
0.98
D;D;.;.
Vest4
0.94
MVP
0.97
MPC
0.32
ClinPred
0.86
D
GERP RS
4.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.53
gMVP
0.93

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.040
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.

Other links and lift over

dbSNP: rs148609143; hg19: chr11-71150037; COSMIC: COSV100831917; COSMIC: COSV100831917; API