8-64616016-C-T

Position:

• chr8-64616016-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_004820.5(CYP7B1):​c.525G>A​(p.Trp175*) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CYP7B1 NM_004820.5 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 6.94

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]

ACMG classification

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 8-64616016-C-T is Pathogenic according to our data. Variant chr8-64616016-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 240074.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CYP7B1	NM_004820.5	c.525G>A	p.Trp175*	stop_gained	3/6	ENST00000310193.4	NP_004811.1
CYP7B1	NM_001324112.2	c.525G>A	p.Trp175*	stop_gained	3/7		NP_001311041.1
CYP7B1	XM_017014002.2	c.591G>A	p.Trp197*	stop_gained	4/7		XP_016869491.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CYP7B1	ENST00000310193.4	c.525G>A	p.Trp175*	stop_gained	3/6	1	NM_004820.5	ENSP00000310721.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Spastic paraplegia Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 04, 2023

This sequence change creates a premature translational stop signal (p.Trp175*) in the CYP7B1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CYP7B1 are known to be pathogenic (PMID: 9802883, 19363635, 19439420, 21541746, 21567895, 28039895). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with hereditary spastic paraplegia (Invitae). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 240074). For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Mayo Clinic Laboratories, Mayo Clinic

Jun 19, 2024

PM2, PS1, PVS1 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	35
DANN	Uncertain	0.99
Eigen	Pathogenic	0.97
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Pathogenic	0.99	D
Vest4		0.91
GERP RS		5.3

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

LitVar

Other links and lift over

dbSNP: rs794727501; hg19: chr8-65528573;