rs121909767

Positions:

chr11-71444950-C-T

Variant summary

Our verdict is Pathogenic. Variant got 20 ACMG points: 20P and 0B. PVS1PS1_ModeratePM2PP5_Very_Strong

The NM_001360.3(DHCR7):c.3G>A(p.Met1?) variant causes a start lost change. The variant allele was found at a frequency of 0.000013 in 1,613,968 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 (★★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

DHCR7
NM_001360.3 start_lost

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 3.62

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 20 ACMG points.

PVS1

Start lost variant, no new inframe start found.

PS1

Another start lost variant in NM_001360.3 (DHCR7) was described as [Likely_pathogenic] in ClinVar as 6794

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 11-71444950-C-T is Pathogenic according to our data. Variant chr11-71444950-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 6791.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-71444950-C-T 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.3G>A	p.Met1?	start_lost	3/9	ENST00000355527.8
DHCR7	NM_001163817.2 linkuse as main transcript	c.3G>A	p.Met1?	start_lost	3/9
DHCR7	XM_011544777.3 linkuse as main transcript	c.3G>A	p.Met1?	start_lost	3/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DHCR7	ENST00000355527.8 linkuse as main transcript	c.3G>A	p.Met1?	start_lost	3/9	1	NM_001360.3	P1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152196

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:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251484

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135914

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:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000116

AC:

AN:

1461772

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727206

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:

0.0000187

Gnomad4 NFE exome

AF:

0.0000135

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152196

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74332

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:

0.0000588

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000101

Hom.:

Bravo

AF:

0.0000113

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Smith-Lemli-Opitz syndrome

Pathogenic:4

Pathogenic, no assertion criteria provided	literature only	OMIM	Sep 15, 2003	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Sep 28, 2020	Variant summary: DHCR7 c.3G>A (p.Met1?; p.Met1Ile) alters the initiation codon and is predicted to result either in absence of the protein or truncation of the encoded protein due to translation initiation at a downstream codon. At-least one report describes evidence supporting alternative translation initiation from the downsteam Methionine codon 59 of the wild-type DHCR7 protein and that the first N-terminal 58 amino acids are not required for enzyme activity apriori (Wassif_1998). Another variant, c.1A>G (p.Met1?, reported as p.Met1Val) has also been reported in a patient with Smith-Lemli-Opitz Syndrome (Witsch-Baumgartner_2005). Two of three in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251484 control chromosomes. c.3G>A has been reported in the literature as a compound heterozygous genotype in at-least three individuals affected with milder clinical manifestations of Smith-Lemli-Opitz Syndrome (example, Waterham_2000, Langius_2003) and has been subsequently cited by others (example, Scalco_2005, Witsch-Baumgartner_2005, Correa-Cerro_2005, Jezela-Stanek_2008). These data indicate that the variant may be associated with disease. To our knowledge, no variant specific experimental evidence demonstrating an impact on protein function has been reported. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. One clinical diagnostic laboratory has submitted clinical significance assessment as likely pathogenic to ClinVar before 2014. Based on the evidence outlined above, the variant was classified as likely pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Sep 10, 2023	For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 6791). Disruption of the initiator codon has been observed in individual(s) with Smith‚ÄìLemli‚ÄìOpitz syndrome (PMID: 12949967). This variant is present in population databases (rs121909767, gnomAD 0.0009%). This sequence change affects the initiator methionine of the DHCR7 mRNA. The next in-frame methionine is located at codon 59. -
Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	Jul 07, 2014	- -

not provided

Pathogenic:4

Pathogenic, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, Amsterdam University Medical Center	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jul 06, 2023	As this variant changes the translation initiator Methionine codon, the resultant protein is described as p.Met1?, using a question mark to signify that it is not known if the loss of Met1 means that all protein translation is completely prevented or if an abnormal protein is produced using an alternate Methionine; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 12949967, 11111101, 23042628, 11767235, 11453964) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.62

BayesDel_noAF

Pathogenic

0.53

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Benign

0.37

T;T;.;T;T;T;T

Eigen

Uncertain

0.26

Eigen_PC

Uncertain

0.25

FATHMM_MKL

Uncertain

0.95

M_CAP

Pathogenic

0.91

MetaRNN

Pathogenic

0.86

D;D;D;D;D;D;D

MetaSVM

Pathogenic

0.89

MutationTaster

Benign

1.0

A;A

PROVEAN

Benign

-0.89

N;N;N;N;N;N;N

REVEL

Pathogenic

0.73

Sift

Pathogenic

0.0

D;D;D;D;D;D;D

Sift4G

Pathogenic

0.0

D;D;.;.;D;.;D

Polyphen

0.90

P;P;.;.;.;.;.

Vest4

0.99

MutPred

0.56

Gain of catalytic residue at M1 (P = 0.0361);Gain of catalytic residue at M1 (P = 0.0361);Gain of catalytic residue at M1 (P = 0.0361);Gain of catalytic residue at M1 (P = 0.0361);Gain of catalytic residue at M1 (P = 0.0361);Gain of catalytic residue at M1 (P = 0.0361);Gain of catalytic residue at M1 (P = 0.0361);

MVP

0.93

ClinPred

0.98

GERP RS

4.1

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.85

gMVP

0.65

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

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