2-219570251-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_015311.3(OBSL1):c.982A>G(p.Thr328Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000698 in 1,433,212 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. T328T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000070 (0 hom.)
• Consequence: OBSL1 NM_015311.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.99

Genes affected

OBSL1 (HGNC:29092): (obscurin like cytoskeletal adaptor 1) Cytoskeletal adaptor proteins function in linking the internal cytoskeleton of cells to the cell membrane. This gene encodes a cytoskeletal adaptor protein, which is a member of the Unc-89/obscurin family. The protein contains multiple N- and C-terminal immunoglobulin (Ig)-like domains and a central fibronectin type 3 domain. Mutations in this gene cause 3M syndrome type 2. Alternatively spliced transcript variants encoding different isoforms have been found in this gene. [provided by RefSeq, Mar 2010]

INHA (HGNC:6065): (inhibin subunit alpha) This gene encodes a member of the TGF-beta (transforming growth factor-beta) superfamily of proteins. The encoded preproprotein is proteolytically processed to generate multiple peptide products, including the alpha subunit of the inhibin A and B protein complexes. These complexes negatively regulate follicle stimulating hormone secretion from the pituitary gland. Inhibins have also been implicated in regulating numerous cellular processes including cell proliferation, apoptosis, immune response and hormone secretion. Mutations in this gene may be associated with male infertility and premature ovarian failure in female human patients. [provided by RefSeq, Aug 2016]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.37409085).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
OBSL1	NM_015311.3	c.982A>G	p.Thr328Ala	missense_variant	1/21	ENST00000404537.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
OBSL1	ENST00000404537.6	c.982A>G	p.Thr328Ala	missense_variant	1/21	1	NM_015311.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000453 AC: 1 AN: 220874 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 120374

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: 0.0000385

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000698 AC: 10 AN: 1433212 Hom.: 0 Cov.: 30 AF XY: 0.00000423 AC XY: 3 AN XY: 708916

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: 0.0000245

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000730

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000509 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000831 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 07, 2023

This variant has not been reported in the literature in individuals affected with OBSL1-related conditions. 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. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 1035173). 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 sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 328 of the OBSL1 protein (p.Thr328Ala). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.66
BayesDel_addAF	Uncertain	0.027	T
BayesDel_noAF	Benign	-0.20
Cadd	Uncertain	24
Dann	Uncertain	0.99
DEOGEN2	Benign	0.20	T;.;.;.
Eigen	Uncertain	0.36
Eigen_PC	Uncertain	0.37
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Benign	0.81	T;T;T;T
M_CAP	Benign	0.085	D
MetaRNN	Benign	0.37	T;T;T;T
MetaSVM	Benign	-0.49	T
MutationAssessor	Benign	0.15	N;.;N;N
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-4.4	D;D;.;D
REVEL	Uncertain	0.56
Sift	Benign	0.067	T;T;.;T
Sift4G	Uncertain	0.024	D;D;D;D
Polyphen		1.0	D;.;.;D
Vest4		0.41
MutPred		0.46		Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);Loss of sheet (P = 0.0817);
MVP		0.72
MPC		0.67
ClinPred		0.71	D
GERP RS		4.8
Varity_R		0.49
gMVP		0.68

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: rs759218624; hg19: chr2-220434973;