dbSNP rs755532803: CYP27A1:p.Phe222LeufsTer13 (chr2-218812568-GTTCGAGAAACGCA-G) – ACMG Classification: Pathogenic (18 pts)

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000784.4(CYP27A1):c.666_678delCGAGAAACGCATT(p.Phe222LeufsTer13) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,614,100 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

CYP27A1
NM_000784.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 9.94

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 2-218812568-GTTCGAGAAACGCA-G is Pathogenic according to our data. Variant chr2-218812568-GTTCGAGAAACGCA-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 498394.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 link	c.666_678delCGAGAAACGCATT	p.Phe222LeufsTer13	frameshift_variant	Exon 4 of 9	ENST00000258415.9	NP_000775.1	Q02318

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CYP27A1	ENST00000258415.9 link	c.666_678delCGAGAAACGCATT	p.Phe222LeufsTer13	frameshift_variant	Exon 4 of 9	1	NM_000784.4	ENSP00000258415.4		Q02318

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152212

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000796

AC:

AN:

251402

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135884

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000342

AC:

AN:

1461888

Hom.:

AF XY:

0.00000413

AC XY:

AN XY:

727246

show subpopulations

Gnomad4 AFR exome

AF:

0.000149

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:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152212

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74374

show subpopulations

Gnomad4 AFR

AF:

0.0000724

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.0000227

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cholestanol storage disease

Pathogenic:3

Jun 20, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 21, 2024

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Phe222Leufs*13) in the CYP27A1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CYP27A1 are known to be pathogenic (PMID: 9392430, 10775536, 26937392). This variant is present in population databases (rs755532803, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with CYP27A1-related conditions. ClinVar contains an entry for this variant (Variation ID: 498394). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

not provided

Pathogenic:2

Feb 23, 2018

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

A variant that is likely pathogenic has been identified in the CYP27A1 gene. The c.666_678del13 variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The c.666_678del13 variant causes a frameshift starting with codon Phenylalanine 222, changes this amino acid to a Leucine residue, and creates a premature Stop codon at position 4 of the new reading frame, denoted p.Phe222LeufsX13. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. Furthermore, the c.666_678del13 variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016). Therefore, this variant is likely pathogenic; however, the possibility that it is benign cannot be excluded. -

Nov 06, 2017

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

CYP27A1-related disorder

Pathogenic:1

May 09, 2024

PreventionGenetics, part of Exact Sciences

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The CYP27A1 c.666_678del13 variant is predicted to result in a frameshift and premature protein termination (p.Phe222Leufs*13). To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.012% of alleles in individuals of African descent in gnomAD. Frameshift variants in CYP27A1 are expected to be pathogenic. This variant is interpreted as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over