rs80338857

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM2PM5PP3_StrongPP5_Moderate

The NM_001360.3(DHCR7):​c.725G>T​(p.Arg242Leu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R242C) has been classified as Pathogenic.

Frequency

Genomes: not found (cov: 34)

Consequence

DHCR7
NM_001360.3 missense

Scores

16
2
1

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 6.79
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 10 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr11-71438986-G-A is described in Lovd as [Pathogenic].
PP3
MetaRNN computational evidence supports a deleterious effect, 0.989
PP5
Variant 11-71438985-C-A is Pathogenic according to our data. Variant chr11-71438985-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2748684.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
DHCR7NM_001360.3 linkc.725G>T p.Arg242Leu 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.725G>T p.Arg242Leu missense_variant Exon 7 of 9 1 NM_001360.3 ENSP00000347717.4 Q9UBM7
DHCR7ENST00000685320.1 linkc.140G>T p.Arg47Leu missense_variant Exon 6 of 8 ENSP00000509319.1 B4E1K5

Frequencies

GnomAD3 genomes
Cov.:
34
GnomAD4 exome
Cov.:
33
GnomAD4 genome
Cov.:
34

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Smith-Lemli-Opitz syndrome Pathogenic:1
Jul 31, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with DHCR7-related conditions. 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. This variant disrupts the p.Arg242 amino acid residue in DHCR7. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10405455, 10677299, 10995508, 15464432, 15954111, 26969503). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 242 of the DHCR7 protein (p.Arg242Leu). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.98
BayesDel_addAF
Pathogenic
0.56
D
BayesDel_noAF
Pathogenic
0.57
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.99
D;D;D;.
Eigen
Pathogenic
0.81
Eigen_PC
Pathogenic
0.71
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.97
.;D;D;D
M_CAP
Pathogenic
0.45
D
MetaRNN
Pathogenic
0.99
D;D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
4.2
H;H;.;.
PrimateAI
Pathogenic
0.85
D
PROVEAN
Pathogenic
-6.7
D;D;D;D
REVEL
Pathogenic
0.96
Sift
Pathogenic
0.0
D;D;D;D
Sift4G
Pathogenic
0.0
D;D;D;.
Polyphen
1.0
D;D;.;.
Vest4
0.99
MutPred
0.92
Loss of methylation at R242 (P = 0.0055);Loss of methylation at R242 (P = 0.0055);.;.;
MVP
0.97
MPC
0.63
ClinPred
1.0
D
GERP RS
4.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.91
gMVP
0.99

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr11-71150031; COSMIC: COSV62795606; COSMIC: COSV62795606; API