NM_000784.4:c.1573C>T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PVS1_ModeratePM2PP5

The NM_000784.4(CYP27A1):​c.1573C>T​(p.Gln525*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,461,862 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 Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. Q525Q) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

CYP27A1
NM_000784.4 stop_gained

Scores

2
3
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:1

Conservation

PhyloP100: 2.27

Publications

4 publications found
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 Gene-Disease associations (from GenCC):
  • cerebrotendinous xanthomatosis
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, Genomics England PanelApp, G2P

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.0144 CDS is truncated, and there are 1 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 2-218815007-C-T is Pathogenic according to our data. Variant chr2-218815007-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 555220.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CYP27A1NM_000784.4 linkc.1573C>T p.Gln525* stop_gained Exon 9 of 9 ENST00000258415.9 NP_000775.1 Q02318

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CYP27A1ENST00000258415.9 linkc.1573C>T p.Gln525* stop_gained Exon 9 of 9 1 NM_000784.4 ENSP00000258415.4 Q02318
CYP27A1ENST00000494263.5 linkn.2285C>T non_coding_transcript_exon_variant Exon 7 of 7 2

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251464
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS 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:
0.00000616
AC:
9
AN:
1461862
Hom.:
0
Cov.:
32
AF XY:
0.00000688
AC XY:
5
AN XY:
727234
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
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:
86254
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:
1111984
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.514
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.0000565
Hom.:
0
Bravo
AF:
0.0000113
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:2Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Cholestanol storage disease Pathogenic:2Uncertain:1
Jan 17, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Gln525*) in the CYP27A1 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 7 amino acid(s) of the CYP27A1 protein. This variant is present in population databases (no rsID available, gnomAD 0.003%). This premature translational stop signal has been observed in individual(s) with cerebrotendinous xanthomatosis (PMID: 21404287). ClinVar contains an entry for this variant (Variation ID: 555220). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Nov 29, 2017
Counsyl
Significance:Likely pathogenic
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. -

Mar 21, 2024
Baylor Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.38
D
BayesDel_noAF
Pathogenic
0.39
CADD
Pathogenic
36
DANN
Uncertain
0.99
Eigen
Uncertain
0.43
Eigen_PC
Uncertain
0.24
FATHMM_MKL
Benign
0.69
D
PhyloP100
2.3
Vest4
0.55
GERP RS
2.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Mutation Taster
=31/169
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

Publications

Other links and lift over

dbSNP: rs374507635; hg19: chr2-219679730; API