rs1354718634

Variant names:

• chr11-71435526-T-G
• rs1354718634
• NM_001360.3:c.1277A>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Moderate PP5_Moderate

The NM_001360.3(DHCR7):​c.1277A>C​(p.His426Pro) variant causes a missense change. The variant allele was found at a frequency of 0.00000186 in 1,611,014 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. H426L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: DHCR7 NM_001360.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1 U:1
• Conservation: PhyloP100: 6.99
• Publications: 3 publications found

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)

ACMG classification

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

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.897
• PP5: Variant 11-71435526-T-G is Pathogenic according to our data. Variant chr11-71435526-T-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 554159.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DHCR7	NM_001360.3	c.1277A>C	p.His426Pro	missense_variant	Exon 9 of 9	ENST00000355527.8	NP_001351.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DHCR7	ENST00000355527.8	c.1277A>C	p.His426Pro	missense_variant	Exon 9 of 9	1	NM_001360.3	ENSP00000347717.4
DHCR7	ENST00000685320.1	c.692A>C	p.His231Pro	missense_variant	Exon 8 of 8			ENSP00000509319.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152194 Hom.: 0 Cov.: 33

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

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1458820 Hom.: 0 Cov.: 30 AF XY: 0.00000276 AC XY: 2 AN XY: 725872

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44702

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26116

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50886

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111622

Other (OTH) AF: 0.00 AC: 0 AN: 60314

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152194 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74350

African (AFR) AF: 0.00 AC: 0 AN: 41450

American (AMR) AF: 0.00 AC: 0 AN: 15288

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5182

South Asian (SAS) AF: 0.00 AC: 0 AN: 4836

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10628

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68020

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Smith-Lemli-Opitz syndrome Pathogenic:1 Uncertain:1

Aug 31, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces histidine, which is basic and polar, with proline, which is neutral and non-polar, at codon 426 of the DHCR7 protein (p.His426Pro). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with Smith-Lemli-Opitz syndrome (PMID: 15896653, 15954111). ClinVar contains an entry for this variant (Variation ID: 554159). 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. -

Sep 27, 2017

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	Uncertain	0.39
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	27
DANN	Uncertain	0.98
DEOGEN2	Pathogenic	0.96	D;D;D
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.96	.;D;D
M_CAP	Uncertain	0.26	D
MetaRNN	Pathogenic	0.90	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.7	H;H;.
PhyloP100		7.0
PrimateAI	Uncertain	0.52	T
PROVEAN	Pathogenic	-6.6	D;D;D
REVEL	Pathogenic	0.93
Sift	Uncertain	0.0060	D;D;D
Sift4G	Uncertain	0.0050	D;D;D
Polyphen		1.0	D;D;.
Vest4		0.96
MutPred		0.63		Gain of glycosylation at H426 (P = 0.0507);Gain of glycosylation at H426 (P = 0.0507);.;
MVP		0.99
MPC		0.71
ClinPred		1.0	D
GERP RS		5.1
Varity_R		0.92
gMVP		0.98
Mutation Taster		=0/100	disease causing

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

Other links and lift over

dbSNP: rs1354718634; hg19: chr11-71146572;