rs370748173

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The ENST00000355527.8(DHCR7):​c.223A>T​(p.Ile75Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000253 in 1,613,504 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. I75I) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00027 ( 1 hom. )

Consequence

DHCR7
ENST00000355527.8 missense

Scores

3
16

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:8

Conservation

PhyloP100: -2.84
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 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.14733475).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
DHCR7NM_001360.3 linkuse as main transcriptc.223A>T p.Ile75Phe missense_variant 4/9 ENST00000355527.8 NP_001351.2
DHCR7NM_001163817.2 linkuse as main transcriptc.223A>T p.Ile75Phe missense_variant 4/9 NP_001157289.1
DHCR7XM_011544777.3 linkuse as main transcriptc.223A>T p.Ile75Phe missense_variant 4/9 XP_011543079.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
DHCR7ENST00000355527.8 linkuse as main transcriptc.223A>T p.Ile75Phe missense_variant 4/91 NM_001360.3 ENSP00000347717 P1

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
152196
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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:
0.0000882
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.000112
AC:
28
AN:
249596
Hom.:
0
AF XY:
0.000111
AC XY:
15
AN XY:
134986
show subpopulations
Gnomad AFR exome
AF:
0.000125
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:
0.000168
Gnomad OTH exome
AF:
0.000492
GnomAD4 exome
AF:
0.000274
AC:
401
AN:
1461308
Hom.:
1
Cov.:
30
AF XY:
0.000279
AC XY:
203
AN XY:
726868
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.0000896
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.0000188
Gnomad4 NFE exome
AF:
0.000348
Gnomad4 OTH exome
AF:
0.000132
GnomAD4 genome
AF:
0.0000526
AC:
8
AN:
152196
Hom.:
0
Cov.:
33
AF XY:
0.0000404
AC XY:
3
AN XY:
74348
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.000131
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000882
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000223
Hom.:
0
Bravo
AF:
0.000110
TwinsUK
AF:
0.000539
AC:
2
ALSPAC
AF:
0.000519
AC:
2
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000988
AC:
12
EpiCase
AF:
0.000273
EpiControl
AF:
0.000357

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Smith-Lemli-Opitz syndrome Uncertain:4
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpSep 27, 2022This sequence change replaces isoleucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 75 of the DHCR7 protein (p.Ile75Phe). This variant is present in population databases (rs370748173, gnomAD 0.02%). 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: 197193). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on 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. -
Uncertain significance, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 13, 2018This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
Uncertain significance, no assertion criteria providedclinical testingNatera, Inc.Mar 27, 2017- -
Uncertain significance, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsOct 31, 2018- -
not provided Uncertain:2
Uncertain significance, criteria provided, single submitterclinical testingGeneDxNov 01, 2021In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -
Uncertain significance, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Jan 05, 2015- -
not specified Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingGenetic Services Laboratory, University of ChicagoApr 15, 2019- -
Inborn genetic diseases Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingAmbry GeneticsDec 02, 2020The c.223A>T (p.I75F) alteration is located in exon 4 (coding exon 2) of the DHCR7 gene. This alteration results from a A to T substitution at nucleotide position 223, causing the isoleucine (I) at amino acid position 75 to be replaced by a phenylalanine (F). The p.I75F alteration is predicted to be tolerated by in silico analysis. 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
0.079
BayesDel_addAF
Benign
-0.090
T
BayesDel_noAF
Benign
-0.090
CADD
Benign
0.037
DANN
Benign
0.78
DEOGEN2
Uncertain
0.45
T;T;.;T;T;T;.;T
Eigen
Benign
-1.7
Eigen_PC
Benign
-1.9
FATHMM_MKL
Benign
0.030
N
LIST_S2
Benign
0.72
.;T;T;T;T;T;T;T
M_CAP
Uncertain
0.094
D
MetaRNN
Benign
0.15
T;T;T;T;T;T;T;T
MetaSVM
Benign
-0.32
T
MutationAssessor
Benign
0.91
L;L;.;.;.;.;.;.
MutationTaster
Benign
1.0
N;N
PrimateAI
Benign
0.34
T
PROVEAN
Benign
-1.5
N;N;N;N;D;N;N;D
REVEL
Uncertain
0.45
Sift
Benign
0.21
T;T;D;D;T;T;D;T
Sift4G
Benign
0.30
T;T;.;.;T;.;.;T
Polyphen
0.23
B;B;.;.;.;.;.;.
Vest4
0.22
MVP
0.52
MPC
0.34
ClinPred
0.034
T
GERP RS
-9.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.039
gMVP
0.60

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs370748173; hg19: chr11-71155137; COSMIC: COSV62794412; COSMIC: COSV62794412; API