17-19343326-G-A

Position:

• chr17-19343326-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_015681.6(B9D1):​c.608C>T​(p.Pro203Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: B9D1 NM_015681.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.27

Genes affected

B9D1 (HGNC:24123): (B9 domain containing 1) This gene encodes a B9 domain-containing protein, one of several that are involved in ciliogenesis. Alterations in expression of this gene have been found in a family with Meckel syndrome. Meckel syndrome has been associated with at least six different genes. This gene is located within the Smith-Magenis syndrome region on chromosome 17. [provided by RefSeq, Mar 2016]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM1: In a chain B9 domain-containing protein 1 (size 203) in uniprot entity B9D1_HUMAN there are 9 pathogenic changes around while only 2 benign (82%) in NM_015681.6
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.0682978).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
B9D1	NM_015681.6	c.608C>T	p.Pro203Leu	missense_variant	7/7	ENST00000261499.11	NP_056496.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
B9D1	ENST00000261499.11	c.608C>T	p.Pro203Leu	missense_variant	7/7	1	NM_015681.6	ENSP00000261499	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Meckel-Gruber syndrome;C0431399:Familial aplasia of the vermis Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 12, 2022

This variant is not present in population databases (gnomAD no frequency). This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 203 of the B9D1 protein (p.Pro203Leu). This variant has not been reported in the literature in individuals affected with B9D1-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0". The leucine 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	0.073
BayesDel_addAF	Benign	-0.12	T
BayesDel_noAF	Benign	-0.41
CADD	Benign	18
DANN	Uncertain	0.99
DEOGEN2	Benign	0.0082	T
Eigen	Benign	-0.84
Eigen_PC	Benign	-0.84
FATHMM_MKL	Benign	0.061	N
LIST_S2	Benign	0.36	T
M_CAP	Benign	0.030	D
MetaRNN	Benign	0.068	T
MetaSVM	Benign	-0.99	T
MutationAssessor	Benign	0.29	N
MutationTaster	Benign	1.0	N;N;N;N;N
PrimateAI	Benign	0.35	T
PROVEAN	Benign	-0.53	N
REVEL	Benign	0.13
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		0.0	B
Vest4		0.17
MutPred		0.25		Loss of glycosylation at P203 (P = 0.0384);
MVP		0.30
MPC		0.79
ClinPred		0.38	T
GERP RS		2.0
Varity_R		0.048
gMVP		0.26

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		Details are displayed if max score is > 0.2

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr17-19246639;