chr19-41354720-G-A

Position:

chr19-41354720-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1PM2

The NM_030578.4(B9D2):c.508C>T(p.Arg170Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000551 in 1,613,892 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R170G) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000060 ( 0 hom. )

Consequence

B9D2
NM_030578.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.30

Variant links:

Genes affected

B9D2 (HGNC:28636): (B9 domain containing 2) This gene encodes a B9 domain protein, which are exclusively found in ciliated organisms. The gene is upregulated during mucociliary differentiation, and the encoded protein localizes to basal bodies and cilia. Disrupting expression of this gene results in ciliogenesis defects. [provided by RefSeq, Oct 2009]

B9D2 links:

TMEM91 (HGNC:32393): (transmembrane protein 91) Predicted to act upstream of or within hematopoietic progenitor cell differentiation. Predicted to be integral component of membrane. Predicted to be active in intracellular membrane-bounded organelle and membrane. [provided by Alliance of Genome Resources, Apr 2022]

TMEM91 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM1

In a chain B9 domain-containing protein 2 (size 174) in uniprot entity B9D2_HUMAN there are 6 pathogenic changes around while only 2 benign (75%) in NM_030578.4

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
B9D2	NM_030578.4 linkuse as main transcript	c.508C>T	p.Arg170Cys	missense_variant	4/4	ENST00000243578.8
B9D2	XM_011527349.3 linkuse as main transcript	c.508C>T	p.Arg170Cys	missense_variant	4/4
B9D2	XM_011527350.3 linkuse as main transcript	c.349C>T	p.Arg117Cys	missense_variant	3/3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
B9D2	ENST00000243578.8 linkuse as main transcript	c.508C>T	p.Arg170Cys	missense_variant	4/4	1	NM_030578.4	P1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152178

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.0000595

AC:

AN:

1461714

Hom.:

Cov.:

AF XY:

0.0000440

AC XY:

AN XY:

727160

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000728

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152178

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74342

show subpopulations

Gnomad4 AFR

AF:

0.0000483

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000189

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.000259

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Meckel-Gruber syndrome;C0431399:Familial aplasia of the vermis

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

May 19, 2022

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 170 of the B9D2 protein (p.Arg170Cys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with B9D2-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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

0.21

BayesDel_addAF

Uncertain

0.035

BayesDel_noAF

Benign

-0.19

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.29

Eigen

Uncertain

0.49

Eigen_PC

Uncertain

0.44

FATHMM_MKL

Uncertain

0.85

LIST_S2

Uncertain

0.96

M_CAP

Pathogenic

0.43

MetaRNN

Uncertain

0.64

MetaSVM

Benign

-0.33

MutationAssessor

Uncertain

2.0

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.53

PROVEAN

Pathogenic

-5.0

REVEL

Uncertain

0.36

Sift

Uncertain

0.0010

Sift4G

Pathogenic

0.0010

Polyphen

1.0

Vest4

0.34

MutPred

0.44

Loss of disorder (P = 0.0137);

MVP

0.67

MPC

0.82

ClinPred

0.99

GERP RS

4.1

Varity_R

0.47

gMVP

0.69

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over