NM_001360.3:c.655T>C

Variant names:

• chr11-71439055-A-G
• rs779896782
• NM_001360.3:c.655T>C
• DHCR7 p.Tyr219His

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM2 PM5 PP3_Moderate PP5_Moderate

The NM_001360.3(DHCR7):​c.655T>C​(p.Tyr219His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,734 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. Y219D) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: DHCR7 NM_001360.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.01
• Publications: 2 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, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), G2P, ClinGen, Myriad Women's Health

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-71439055-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 430220.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.896
• PP5: Variant 11-71439055-A-G is Pathogenic according to our data. Variant chr11-71439055-A-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 374209.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001360.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	DHCR7	NM_001360.3	MANE Select	c.655T>C	p.Tyr219His	missense	Exon 7 of 9	NP_001351.2	A0A024R5F7
	DHCR7	NM_001425107.1		c.706T>C	p.Tyr236His	missense	Exon 8 of 10	NP_001412036.1	A0A804HI25
	DHCR7	NM_001425108.1		c.691T>C	p.Tyr231His	missense	Exon 7 of 9	NP_001412037.1	A0A804HJQ7

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	DHCR7	ENST00000355527.8	TSL:1 MANE Select	c.655T>C	p.Tyr219His	missense	Exon 7 of 9	ENSP00000347717.4	Q9UBM7
	DHCR7	ENST00000407721.6	TSL:1	c.655T>C	p.Tyr219His	missense	Exon 7 of 9	ENSP00000384739.2	Q9UBM7
	DHCR7	ENST00000685320.1		c.70T>C	p.Tyr24His	missense	Exon 6 of 8	ENSP00000509319.1	B4E1K5

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461734 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727152

African (AFR) AF: 0.0000299 AC: 1 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53278

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112004

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome Cov.: 34

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	Small for gestational age;C1849185:Elevated circulating 7-dehydrocholesterol concentration;C2677180:Primary microcephaly;C4551570:2-3 toe syndactyly (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.83
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.19
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	D
Eigen	Uncertain	0.65
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D
M_CAP	Uncertain	0.26	D
MetaRNN	Pathogenic	0.90	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.9	M
PhyloP100		8.0
PrimateAI	Uncertain	0.71	T
PROVEAN	Uncertain	-3.6	D
REVEL	Pathogenic	0.87
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0030	D
PromoterAI		0.059	Neutral
Varity_R		0.48
gMVP		0.98
Mutation Taster		=63/37	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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs779896782;

hg19: chr11-71150101;