rs759720450

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_001360.3(DHCR7):​c.1057delG​(p.Val353TrpfsTer60) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000992 in 1,612,212 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 35)
Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

DHCR7
NM_001360.3 frameshift

Scores

Not classified

Clinical Significance

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

Conservation

PhyloP100: 0.525

Publications

2 publications found
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 Gene-Disease associations (from GenCC):
  • Smith-Lemli-Opitz syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Myriad Women’s Health, Laboratory for Molecular Medicine, ClinGen, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 76 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 11-71435745-AC-A is Pathogenic according to our data. Variant chr11-71435745-AC-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 551481.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
DHCR7NM_001360.3 linkc.1057delG p.Val353TrpfsTer60 frameshift_variant Exon 9 of 9 ENST00000355527.8 NP_001351.2 Q9UBM7A0A024R5F7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
DHCR7ENST00000355527.8 linkc.1057delG p.Val353TrpfsTer60 frameshift_variant Exon 9 of 9 1 NM_001360.3 ENSP00000347717.4 Q9UBM7
DHCR7ENST00000685320.1 linkc.472delG p.Val158TrpfsTer60 frameshift_variant Exon 8 of 8 ENSP00000509319.1 B4E1K5

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152242
Hom.:
0
Cov.:
35
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
GnomAD2 exomes
AF:
0.00000402
AC:
1
AN:
248962
AF XY:
0.00
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000894
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000103
AC:
15
AN:
1459970
Hom.:
0
Cov.:
37
AF XY:
0.0000110
AC XY:
8
AN XY:
726144
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33458
American (AMR)
AF:
0.00
AC:
0
AN:
44708
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26118
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39660
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86244
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52392
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.0000126
AC:
14
AN:
1111288
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60338
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.505
Heterozygous variant carriers
0
1
3
4
6
7
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152242
Hom.:
0
Cov.:
35
AF XY:
0.0000134
AC XY:
1
AN XY:
74380
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41468
American (AMR)
AF:
0.00
AC:
0
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68046
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756

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:5
Jul 19, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Val353Trpfs*60) in the DHCR7 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 123 amino acid(s) of the DHCR7 protein. This variant is present in population databases (rs759720450, gnomAD 0.0009%). This premature translational stop signal has been observed in individual(s) with Smith-Lemli-Opitz syndrome (PMID: 11111101). ClinVar contains an entry for this variant (Variation ID: 551481). This variant disrupts a region of the DHCR7 protein in which other variant(s) (p.Tyr382*) have been determined to be pathogenic (Invitae). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Dec 02, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: DHCR7 c.1057delG (p.Val353TrpfsX60) results in a premature termination codon and is expected to cause a truncation of the encoded protein, which is a commonly known mechanism for disease. Variants downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 4e-06 in 248962 control chromosomes. c.1057delG has been reported in the literature in at least one individual affected with Smith-Lemli-Opitz Syndrome (e.g. Waterham_2000). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 11111101). ClinVar contains an entry for this variant (Variation ID: 551481). Based on the evidence outlined above, the variant was classified as pathogenic. -

Mar 16, 2017
Natera, Inc.
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Apr 12, 2017
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Jan 29, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
0.53
Mutation Taster
=3/197
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs759720450; hg19: chr11-71146791; API