rs587778795

Variant names:

• chr2-218809754-G-A
• rs587778795
• NM_000784.4:c.433G>A

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000784.4(CYP27A1):​c.433G>A​(p.Gly145Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,028 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. G145E) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: CYP27A1 NM_000784.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 10.0

Genes affected

CYP27A1 (HGNC:2605): (cytochrome P450 family 27 subfamily A member 1) This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This mitochondrial protein oxidizes cholesterol intermediates as part of the bile synthesis pathway. Since the conversion of cholesterol to bile acids is the major route for removing cholesterol from the body, this protein is important for overall cholesterol homeostasis. Mutations in this gene cause cerebrotendinous xanthomatosis, a rare autosomal recessive lipid storage disease. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-218809755-G-A is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991
• PP5: Variant 2-218809754-G-A is Pathogenic according to our data. Variant chr2-218809754-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 65868.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
CYP27A1	NM_000784.4	c.433G>A	p.Gly145Arg	missense_variant	Exon 2 of 9	ENST00000258415.9	NP_000775.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CYP27A1	ENST00000258415.9	c.433G>A	p.Gly145Arg	missense_variant	Exon 2 of 9	1	NM_000784.4	ENSP00000258415.4

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461028 Hom.: 0 Cov.: 32 AF XY: 0.00000550 AC XY: 4 AN XY: 726658

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: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 30

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cholestanol storage disease Pathogenic:4

Jun 01, 2022

Solve-RD Consortium

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: provider interpretation

Variant confirmed as disease-causing by referring clinical team -

Aug 01, 2013

GeneReviews

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: curation

- -

Feb 15, 2024

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 06, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 145 of the CYP27A1 protein (p.Gly145Arg). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with cerebrotendinous xanthomatosis (PMID: 20402754; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 65868). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on CYP27A1 protein function. This variant disrupts the Gly145 amino acid residue in CYP27A1. Other variant(s) that disrupt this residue have been determined to be pathogenic (Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:1

Jan 01, 2018

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.80	D;T
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.89	D;D
M_CAP	Uncertain	0.15	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Uncertain	0.39	D
MutationAssessor	Pathogenic	3.5	H;.
PrimateAI	Uncertain	0.66	T
PROVEAN	Pathogenic	-7.5	D;D
REVEL	Pathogenic	0.81
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.98
MutPred		0.96		Loss of sheet (P = 0.0817);.;
MVP		0.91
MPC		0.79
ClinPred		1.0	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.95
gMVP		0.97

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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

Other links and lift over

dbSNP: rs587778795; hg19: chr2-219674477;