rs779896782

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1PM2PM5PP3_StrongPP5

The NM_001360.3(DHCR7):c.655T>G(p.Tyr219Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,613,974 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y219H) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 34)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

DHCR7
NM_001360.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:2

Conservation

PhyloP100: 8.01

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]

DHCR7 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 11 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_001360.3

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr11-71439055-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 374209.Status of the report is criteria_provided_single_submitter, 1 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.945

PP5

Variant 11-71439055-A-C is Pathogenic according to our data. Variant chr11-71439055-A-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 430220.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=1, Likely_pathogenic=2, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
DHCR7	NM_001360.3 linkuse as main transcript	c.655T>G	p.Tyr219Asp	missense_variant	7/9	ENST00000355527.8
DHCR7	NM_001163817.2 linkuse as main transcript	c.655T>G	p.Tyr219Asp	missense_variant	7/9
DHCR7	XM_011544777.3 linkuse as main transcript	c.655T>G	p.Tyr219Asp	missense_variant	7/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DHCR7	ENST00000355527.8 linkuse as main transcript	c.655T>G	p.Tyr219Asp	missense_variant	7/9	1	NM_001360.3	P1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152240

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000796

AC:

AN:

251320

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135894

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

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:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000123

AC:

AN:

1461734

Hom.:

Cov.:

AF XY:

0.0000151

AC XY:

AN XY:

727152

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000162

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152240

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74380

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000312

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:4Uncertain:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Smith-Lemli-Opitz syndrome

Pathogenic:3Uncertain:1

Likely pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jun 15, 2023	ClinVar contains an entry for this variant (Variation ID: 430220). For these reasons, this variant has been classified as Pathogenic. 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 missense change has been observed in individual(s) with Smith-Lemli-Opitz syndrome (PMID: 18249054). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is present in population databases (rs779896782, gnomAD 0.002%). This sequence change replaces tyrosine, which is neutral and polar, with aspartic acid, which is acidic and polar, at codon 219 of the DHCR7 protein (p.Tyr219Asp). -
Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	-	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Aug 16, 2017	- -

not provided

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Apr 09, 2021

Not observed in large population cohorts (Lek et al., 2016); Missense variants in this gene are often considered pathogenic (Stenson et al., 2014); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 18249054, 23042628, 20556518) -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Jun 07, 2022

Variant summary: DHCR7 c.655T>G (p.Tyr219Asp) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 251320 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.655T>G has been reported in the literature in an individual affected with Smith-Lemli-Opitz Syndrome in the compound heterozygous state (Jezela-Stanek_2008). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Three submitters classified the variant as likely pathogenic/pathogenic while one classified as VUS. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.97

BayesDel_addAF

Pathogenic

0.55

BayesDel_noAF

Pathogenic

0.56

Cadd

Pathogenic

Dann

Uncertain

0.99

DEOGEN2

Pathogenic

0.99

D;D;D;.

Eigen

Uncertain

0.59

Eigen_PC

Uncertain

0.56

FATHMM_MKL

Pathogenic

0.99

M_CAP

Pathogenic

0.42

MetaRNN

Pathogenic

0.95

D;D;D;D

MetaSVM

Pathogenic

1.0

MutationAssessor

Uncertain

2.9

M;M;.;.

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.70

PROVEAN

Pathogenic

-5.9

D;D;D;D

REVEL

Pathogenic

0.93

Sift

Uncertain

0.0020

D;D;D;D

Sift4G

Uncertain

0.0020

D;D;D;.

Polyphen

0.92

P;P;.;.

Vest4

0.90

MutPred

0.78

Loss of stability (P = 0.1245);Loss of stability (P = 0.1245);.;.;

MVP

0.96

MPC

0.49

ClinPred

0.97

GERP RS

4.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.87

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

LitVar

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

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over