rs72551317

Variant names:

• chr2-218812681-A-G
• rs72551317
• NM_000784.4:c.776A>G
• CYP27A1 p.Lys259Arg

Your query was ambiguous. Multiple possible variants found:

• chr2-218812681-A-G
• chr2-218812681-A-C

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PS3 PM2 PP3_Moderate PP5_Very_Strong

The NM_000784.4(CYP27A1):​c.776A>G​(p.Lys259Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,614,038 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV001382860: Experimental studies have shown that this missense change does not substantially affect CYP27A1 function (PMID:17697869).". Synonymous variant affecting the same amino acid position (i.e. K259K) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: CYP27A1 NM_000784.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9
• Conservation: PhyloP100: 2.15
• Publications: 2 publications found

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]

CYP27A1 Gene-Disease associations (from GenCC):

• cerebrotendinous xanthomatosis

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, Myriad Women's Health, ClinGen, G2P, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Pathogenic. The variant received 16 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV001382860: Experimental studies have shown that this missense change does not substantially affect CYP27A1 function (PMID: 17697869).
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 2-218812681-A-G is Pathogenic according to our data. Variant chr2-218812681-A-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 65898.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000784.4. 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
	CYP27A1	NM_000784.4	MANE Select	c.776A>G	p.Lys259Arg	missense	Exon 4 of 9	NP_000775.1	Q02318

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CYP27A1	ENST00000258415.9	TSL:1 MANE Select	c.776A>G	p.Lys259Arg	missense	Exon 4 of 9	ENSP00000258415.4	Q02318
	CYP27A1	ENST00000901552.1		c.776A>G	p.Lys259Arg	missense	Exon 4 of 9	ENSP00000571611.1
	CYP27A1	ENST00000901553.1		c.794A>G	p.Lys265Arg	missense	Exon 4 of 9	ENSP00000571612.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152144 Hom.: 0 Cov.: 32

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: 0.0000159 AC: 4 AN: 251474 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000264

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461894 Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 727248

African (AFR) AF: 0.00 AC: 0 AN: 33480

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

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

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 0.00000540 AC: 6 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152144 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74328

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41426

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5198

South Asian (SAS) AF: 0.00 AC: 0 AN: 4818

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10608

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

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2090

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.0000328 Hom.: 0

Bravo AF: 0.00000756

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
6	-	-	Cholestanol storage disease (6)
3	-	-	not provided (3)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.069
BayesDel_addAF	Benign	-0.049	T
BayesDel_noAF	Benign	-0.14
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Benign	0.18	T
Eigen	Benign	-0.34
Eigen_PC	Benign	-0.18
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Benign	0.76	T
M_CAP	Benign	0.0079	T
MetaRNN	Benign	0.38	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.7	L
PhyloP100		2.2
PrimateAI	Benign	0.37	T
PROVEAN	Benign	-1.0	N
REVEL	Uncertain	0.36
Sift	Benign	0.33	T
Sift4G	Benign	0.68	T
Varity_R		0.11
gMVP		0.58
Mutation Taster		=44/56	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.98		Position offset: 1

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: rs72551317; hg19: chr2-219677404;