chr8-64615194-T-C

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong

The NM_004820.5(CYP7B1):c.889A>G(p.Thr297Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000248 in 1,613,262 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 Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. T297T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000025 ( 0 hom. )

Consequence

CYP7B1
NM_004820.5 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:9

Conservation

PhyloP100: 3.42

Publications

8 publications found

Variant links:

Genes affected

CYP7B1 (HGNC:2652): (cytochrome P450 family 7 subfamily B 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 endoplasmic reticulum membrane protein catalyzes the first reaction in the cholesterol catabolic pathway of extrahepatic tissues, which converts cholesterol to bile acids. This enzyme likely plays a minor role in total bile acid synthesis, but may also be involved in the development of atherosclerosis, neurosteroid metabolism and sex hormone synthesis. Mutations in this gene have been associated with hereditary spastic paraplegia (SPG5 or HSP), an autosomal recessive disorder. [provided by RefSeq, Apr 2016]

CYP7B1 Gene-Disease associations (from GenCC):

congenital bile acid synthesis defect 3
Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Orphanet
hereditary spastic paraplegia 5A
Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp

CYP7B1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 14 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.965

PP5

Variant 8-64615194-T-C is Pathogenic according to our data. Variant chr8-64615194-T-C is described in ClinVar as Pathogenic. ClinVar VariationId is 120179.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
CYP7B1	NM_004820.5 link	c.889A>G	p.Thr297Ala	missense_variant	Exon 4 of 6	ENST00000310193.4	NP_004811.1	O75881Q05C57
CYP7B1	NM_001324112.2 link	c.889A>G	p.Thr297Ala	missense_variant	Exon 4 of 7		NP_001311041.1	Q05C57
CYP7B1	XM_017014002.2 link	c.955A>G	p.Thr319Ala	missense_variant	Exon 5 of 7		XP_016869491.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CYP7B1	ENST00000310193.4 link	c.889A>G	p.Thr297Ala	missense_variant	Exon 4 of 6	1	NM_004820.5	ENSP00000310721.3		O75881
CYP7B1	ENST00000523954.1 link	n.163A>G		non_coding_transcript_exon_variant	Exon 2 of 5	3

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152032

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000656

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:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000279

AC:

AN:

250902

AF XY:

0.0000295

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000617

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000246

AC:

AN:

1461230

Hom.:

Cov.:

AF XY:

0.0000220

AC XY:

AN XY:

726904

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33452

American (AMR)

AF:

0.00

AC:

AN:

44608

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26116

East Asian (EAS)

AF:

0.00

AC:

AN:

39690

South Asian (SAS)

AF:

0.00

AC:

AN:

86242

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53374

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.0000315

AC:

AN:

1111638

Other (OTH)

AF:

0.0000166

AC:

AN:

60346

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.483

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:

0.0000263

AC:

AN:

152032

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74260

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41382

American (AMR)

AF:

0.0000656

AC:

AN:

15248

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5192

South Asian (SAS)

AF:

0.00

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10602

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

68002

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000988

Hom.:

Bravo

AF:

0.0000151

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ExAC

AF:

0.0000330

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000119

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hereditary spastic paraplegia 5A

Pathogenic:4

Nov 14, 2023

Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Feb 01, 2012

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

- -

Paris Brain Institute, Inserm - ICM

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 01, 2019

Institute of Human Genetics, University of Leipzig Medical Center

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Pathogenic:2

May 17, 2023

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 21214876, 19439420, 24519355, 19687010, 29246610, 31692161, 21541746, 25073475, 23180418, 22384504, 29246618, 29228183, 29126212, 34426522, 31589614) -

Mar 01, 2021

CeGaT Center for Human Genetics Tuebingen

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Spastic paraplegia

Pathogenic:1

Oct 18, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 297 of the CYP7B1 protein (p.Thr297Ala). This variant is present in population databases (rs587777222, gnomAD 0.006%). This missense change has been observed in individuals with hereditary spastic paraplegia (HSP) (PMID: 19439420, 21214876, 24519355). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 120179). An algorithm developed specifically for the CYP7B1 gene suggests that this missense change is likely to be deleterious (PMID: 21541746). For these reasons, this variant has been classified as Pathogenic. -

CYP7B1-related disorder

Pathogenic:1

Sep 19, 2024

PreventionGenetics, part of Exact Sciences

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

The CYP7B1 c.889A>G variant is predicted to result in the amino acid substitution p.Thr297Ala. This variant has been reported in individuals with spastic paraplegia (Goizet et al. 2009. PubMed ID: 19439420; Di Fabio et al. 2014. PubMed ID: 24519355; Ngo et al 2019. PubMed ID: 31692161). Computing modeling studies suggest that this variant has a direct effect on ligand binding (Siam. 2012. PubMed ID: 21541746). This variant is reported in 0.0054% of alleles in individuals of European (Non-Finnish) descent in gnomAD. This variant is interpreted as pathogenic. -

Hereditary spastic paraplegia

Pathogenic:1

Sep 10, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: CYP7B1 c.889A>G (p.Thr297Ala) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.8e-05 in 250902 control chromosomes. c.889A>G has been reported in the literature in multiple homozygous individuals affected with Hereditary Spastic Paraplegia, Type 5a (Di Fabio_2014, Benkirane_2021). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 34234304, 24519355, 19439420, 34983064, 31692161). ClinVar contains an entry for this variant (Variation ID: 120179). Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.24

BayesDel_addAF

Pathogenic

0.18

BayesDel_noAF

Pathogenic

0.21

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.72

Eigen

Uncertain

0.64

Eigen_PC

Uncertain

0.60

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Benign

0.81

M_CAP

Benign

0.039

MetaRNN

Pathogenic

0.97

MetaSVM

Uncertain

0.23

MutationAssessor

Benign

1.6

PhyloP100

3.4

PrimateAI

Benign

0.39

PROVEAN

Pathogenic

-4.7

REVEL

Pathogenic

0.73

Sift

Uncertain

0.0030

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.95

MutPred

0.83

Loss of stability (P = 0.0697);

MVP

0.92

MPC

0.37

ClinPred

0.77

GERP RS

4.8

Varity_R

0.64

gMVP

0.72

Mutation Taster

=17/83

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over