2-218809756-G-T

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PP3PP5_Very_Strong

The NM_000784.4(CYP27A1):c.435G>T(p.Gly145Gly) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000093 in 1,613,166 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 (★★). Synonymous variant affecting the same amino acid position (i.e. G145G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)

Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

CYP27A1
NM_000784.4 synonymous

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7U:1

Conservation

PhyloP100: -0.482

Publications

15 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

CYP27A1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

PP3

Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

PP5

Variant 2-218809756-G-T is Pathogenic according to our data. Variant chr2-218809756-G-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 65869.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.435G>T	p.Gly145Gly	synonymous_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 link	c.435G>T	p.Gly145Gly	synonymous_variant	Exon 2 of 9	1	NM_000784.4	ENSP00000258415.4

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152166

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000192

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

GnomAD2 exomes

AF:

0.0000239

AC:

AN:

250588

AF XY:

0.0000222

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000326

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000958

AC:

AN:

1461000

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

726644

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33452

American (AMR)

AF:

0.00

AC:

AN:

44702

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26102

East Asian (EAS)

AF:

0.000353

AC:

AN:

39664

South Asian (SAS)

AF:

0.00

AC:

AN:

86222

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53388

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5762

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111358

Other (OTH)

AF:

0.00

AC:

AN:

60350

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.489

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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

AF:

0.00000657

AC:

AN:

152166

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74348

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41428

American (AMR)

AF:

0.00

AC:

AN:

15274

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.000192

AC:

AN:

5198

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10616

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68030

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000560

Hom.:

Bravo

AF:

0.0000151

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cholestanol storage disease

Pathogenic:6Uncertain:1

Mar 18, 2016

Soonchunhyang University Bucheon Hospital, Soonchunhyang University Medical Center

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:reference population

May 09, 2017

Counsyl

Significance:Uncertain significance

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.

Aug 01, 2013

GeneReviews

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:curation

May 08, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Sep 16, 2020

Natera, Inc.

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

Mar 14, 2024

Baylor Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Jun 23, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change affects codon 145 of the CYP27A1 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the CYP27A1 protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or disrupted protein product. This variant is present in population databases (rs587778796, gnomAD 0.04%). This variant has been observed in individuals with cerebrotendinous xanthomatosis (PMID: 9521761, 29321515). It has also been observed to segregate with disease in related individuals. This variant is also known as Gly112Gly. ClinVar contains an entry for this variant (Variation ID: 65869). Studies have shown that this variant results in alternative splicing and introduces a premature termination codon (PMID: 9521761). The resulting mRNA is expected to undergo nonsense-mediated decay. For these reasons, this variant has been classified as Pathogenic.

CYP27A1-related disorder

Pathogenic:1

Feb 14, 2024

PreventionGenetics, part of Exact Sciences

Significance:Likely pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

The CYP27A1 c.435G>T variant is not predicted to result in an amino acid change (p.=). This variant is predicted to alter splicing based on available splicing prediction programs (SpliceAI, Jaganathan et al. 2019. PubMed ID: 30661751) and a RT-PCR study showed this variant impacts mRNA splicing leading to a cryptic GT Donor site (Figure 5, Chen et al. 1998. PubMed ID: 9521761). This variant has been reported in the homozygous and compound heterozygous states in multiple individuals with cerebrotendinous xanthomatosis (Figure 5, Chen et al. 1998. PubMed ID: 9521761; Figure 2, Tang et al. 2020. PubMed ID: 31914338; Figure 1, Cao et al. 2020. PubMed ID: 33269283). This variant is reported in 0.033% of alleles in individuals of East Asian descent in gnomAD. It has also been described as one of the most common variants observed in Japanese individuals with cerebrotendinous xanthomatosis (Sekijima et al. 2018. PubMed ID: 29321515). This variant is interpreted as likely pathogenic.

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.55

CADD

Benign

(source)

DANN

Benign

0.63

PhyloP100

-0.48

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Mutation Taster

=98/2

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.76

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.76

Position offset: -2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over