rs1046560765

Positions:

chr11-71435581-A-G

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong

The NM_001360.3(DHCR7):c.1222T>C(p.Tyr408His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,611,300 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y408F) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 35)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

DHCR7
NM_001360.3 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 8.13

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 18 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 4 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 chr11-71435580-T-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1487172.Status of the report is criteria_provided_single_submitter, 1 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.993

PP5

Variant 11-71435581-A-G is Pathogenic according to our data. Variant chr11-71435581-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 552616.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-71435581-A-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
DHCR7	NM_001360.3 linkuse as main transcript	c.1222T>C	p.Tyr408His	missense_variant	9/9	ENST00000355527.8
DHCR7	NM_001163817.2 linkuse as main transcript	c.1222T>C	p.Tyr408His	missense_variant	9/9
DHCR7	XM_011544777.3 linkuse as main transcript	c.1356T>C	p.Thr452=	synonymous_variant	9/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DHCR7	ENST00000355527.8 linkuse as main transcript	c.1222T>C	p.Tyr408His	missense_variant	9/9	1	NM_001360.3	P1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152214

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000405

AC:

AN:

246792

Hom.:

AF XY:

0.00000744

AC XY:

AN XY:

134360

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:

0.00000896

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1459086

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

725996

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:

0.00000360

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152214

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74366

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000283

Hom.:

Bravo

AF:

0.0000189

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Smith-Lemli-Opitz syndrome

Pathogenic:4

Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	-	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Jun 23, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Aug 31, 2022	This variant is present in population databases (no rsID available, gnomAD 0.0009%). 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. ClinVar contains an entry for this variant (Variation ID: 552616). This missense change has been observed in individual(s) with Smith-Lemli-Opitz syndrome (PMID: 10677299, 10995508, 12818773, 15896653). This sequence change replaces tyrosine, which is neutral and polar, with histidine, which is basic and polar, at codon 408 of the DHCR7 protein (p.Tyr408His). -
Likely pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jan 06, 2023	Variant summary: DHCR7 c.1222T>C (p.Tyr408His) results in a conservative amino acid change located in the 4th Cytoplasmic loop/TM domain (Witsch-Baumgartner_2000) of 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 4.1e-06 in 246792 control chromosomes. c.1222T>C has been reported in the literature as a compound heterozygous genotype in individuals affected with Smith-Lemli-Opitz Syndrome (example, PMID: 10995508, 23918729, 22438180, 33890232, 15896653, 15954111, 10677299). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

not provided

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Sep 09, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Observed multiple times with a second DHCR7 variant in unrelated patients with Smithh-Lemli-Opitz syndrome in published literature, but it is not known whether the variants occurred on the same (in cis) or on different (in trans) chromosomes (Krakowiak et al., 2000; Waye et al., 2005; Lee et al., 2013); This variant is associated with the following publications: (PMID: 11942534, 12818773, 28166604, 34308104, 11767235, 11001806, 15954111, 22438180, 23042628, 10995508, 10677299, 23918729, 12914579, 11111101, 33890232, 18076100, 15896653) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.56

BayesDel_noAF

Pathogenic

0.56

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.99

D;D;D

Eigen

Pathogenic

0.79

Eigen_PC

Pathogenic

0.67

FATHMM_MKL

Uncertain

0.94

M_CAP

Pathogenic

0.66

MetaRNN

Pathogenic

0.99

D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

4.3

H;H;.

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.78

PROVEAN

Pathogenic

-4.7

D;D;D

REVEL

Pathogenic

0.95

Sift

Pathogenic

0.0

D;D;D

Sift4G

Pathogenic

0.0

D;D;D

Polyphen

1.0

D;D;.

Vest4

0.98

MutPred

0.95

Loss of stability (P = 0.0517);Loss of stability (P = 0.0517);.;

MVP

0.99

MPC

0.65

ClinPred

1.0

GERP RS

4.0

Varity_R

0.89

gMVP

0.97

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