8-64798511-G-A

Position:

• chr8-64798511-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The ENST00000310193.4(CYP7B1):​c.77C>T​(p.Ala26Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000125 in 1,355,192 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. A26A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000013 (0 hom.)
• Consequence: CYP7B1 ENST00000310193.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.263

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 Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.08259547).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CYP7B1	NM_004820.5	c.77C>T	p.Ala26Val	missense_variant	1/6	ENST00000310193.4	NP_004811.1
CYP7B1	NM_001324112.2	c.77C>T	p.Ala26Val	missense_variant	1/7		NP_001311041.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CYP7B1	ENST00000310193.4	c.77C>T	p.Ala26Val	missense_variant	1/6	1	NM_004820.5	ENSP00000310721	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000988 AC: 1 AN: 101256 Hom.: 0 AF XY: 0.0000176 AC XY: 1 AN XY: 56698

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000262

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000125 AC: 17 AN: 1355192 Hom.: 0 Cov.: 32 AF XY: 0.0000194 AC XY: 13 AN XY: 668690

Gnomad4 AFR exome AF: 0.00

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: 0.0000159

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.0000113

ExAC AF: 0.0000245 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Spastic paraplegia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 09, 2022

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 26 of the CYP7B1 protein (p.Ala26Val). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with CYP7B1-related conditions. ClinVar contains an entry for this variant (Variation ID: 458231). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Benign	-0.14	T
BayesDel_noAF	Benign	-0.44
CADD	Benign	16
DANN	Uncertain	1.0
DEOGEN2	Benign	0.13	T
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.035	N
LIST_S2	Benign	0.46	T
M_CAP	Uncertain	0.11	D
MetaRNN	Benign	0.083	T
MetaSVM	Benign	-0.96	T
MutationAssessor	Benign	0.0	N
MutationTaster	Benign	1.0	N
PrimateAI	Uncertain	0.56	T
PROVEAN	Benign	0.21	N
REVEL	Benign	0.070
Sift	Benign	0.27	T
Sift4G	Benign	0.067	T
Polyphen		0.052	B
Vest4		0.26
MutPred		0.40		Loss of disorder (P = 0.2062);
MVP		0.58
MPC		0.22
ClinPred		0.069	T
GERP RS		1.0
Varity_R		0.037
gMVP		0.46

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: rs754214163; hg19: chr8-65711068;