Genetic Variant DHCR7:p.Thr319Ala (chr11-71437820-T-C) – ACMG Classification: Likely_pathogenic (6 pts)

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate

The NM_001360.3(DHCR7):c.955A>G(p.Thr319Ala) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T319M) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 34)

Consequence

DHCR7
NM_001360.3 missense

Scores

Clinical Significance

Uncertain significance no assertion criteria provided U:1

Conservation

PhyloP100: 6.99

Publications

0 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)

DHCR7 links:

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ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM1

In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 12 uncertain in NM_001360.3

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.878

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DHCR7	NM_001360.3 link	c.955A>G	p.Thr319Ala	missense_variant	Exon 8 of 9	ENST00000355527.8	NP_001351.2	Q9UBM7A0A024R5F7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DHCR7	ENST00000355527.8 link	c.955A>G	p.Thr319Ala	missense_variant	Exon 8 of 9	1	NM_001360.3	ENSP00000347717.4		Q9UBM7
DHCR7	ENST00000685320.1 link	c.370A>G	p.Thr124Ala	missense_variant	Exon 7 of 8			ENSP00000509319.1		B4E1K5

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251174

AF XY:

0.00000736

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:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: no assertion criteria provided

LINK: link

Submissions by phenotype

Smith-Lemli-Opitz syndrome

Uncertain:1

May 04, 2018

Counsyl

Significance:Uncertain significance

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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.74

BayesDel_addAF

Pathogenic

0.53

BayesDel_noAF

Pathogenic

0.53

CADD

Pathogenic

(source)

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.98

D;D;D;D

Eigen

Uncertain

0.23

Eigen_PC

Benign

0.097

FATHMM_MKL

Uncertain

0.91

LIST_S2

Uncertain

0.92

.;D;D;D

M_CAP

Uncertain

0.15

MetaRNN

Pathogenic

0.88

D;D;D;D

MetaSVM

Pathogenic

1.0

MutationAssessor

Uncertain

2.8

M;M;.;.

PhyloP100

7.0

PrimateAI

Uncertain

0.70

PROVEAN

Pathogenic

-4.7

D;D;D;D

REVEL

Pathogenic

0.79

Sift

Pathogenic

0.0

D;D;D;D

Sift4G

Uncertain

0.0060

D;D;T;D

Polyphen

1.0

D;D;.;.

Vest4

0.90

MutPred

0.66

Loss of helix (P = 0.3949);Loss of helix (P = 0.3949);.;.;

MVP

0.96

MPC

0.54

ClinPred

0.99

GERP RS

3.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.83

gMVP

0.94

Mutation Taster

=12/88

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.10

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over