6-15523022-T-C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_032122.5(DTNBP1):c.1009A>G(p.Thr337Ala) 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: DTNBP1 NM_032122.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.301

Genes affected

DTNBP1 (HGNC:17328): (dystrobrevin binding protein 1) This gene encodes a protein that may play a role in organelle biogenesis associated with melanosomes, platelet dense granules, and lysosomes. A similar protein in mouse is a component of a protein complex termed biogenesis of lysosome-related organelles complex 1 (BLOC-1), and binds to alpha- and beta-dystrobrevins, which are components of the dystrophin-associated protein complex (DPC). Mutations in this gene are associated with Hermansky-Pudlak syndrome type 7. This gene may also be associated with schizophrenia. Multiple transcript variants encoding distinct isoforms have been identified for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.06529707).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DTNBP1	NM_032122.5	c.1009A>G	p.Thr337Ala	missense_variant	10/10	ENST00000344537.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DTNBP1	ENST00000344537.10	c.1009A>G	p.Thr337Ala	missense_variant	10/10	1	NM_032122.5	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

Bravo AF: 0.0000113

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 26, 2022

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The alanine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. ClinVar contains an entry for this variant (Variation ID: 1491228). This variant has not been reported in the literature in individuals affected with DTNBP1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 337 of the DTNBP1 protein (p.Thr337Ala). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.059
BayesDel_addAF	Benign	-0.30	T
BayesDel_noAF	Benign	-0.67
Cadd	Benign	2.3
Dann	Benign	0.63
DEOGEN2	Benign	0.16	T;.;T;.
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.11	N
LIST_S2	Benign	0.57	T;T;T;T
M_CAP	Benign	0.0042	T
MetaRNN	Benign	0.065	T;T;T;T
MetaSVM	Benign	-0.96	T
MutationAssessor	Benign	1.4	L;.;.;.
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Benign	0.37	T
PROVEAN	Benign	-0.97	N;N;.;.
REVEL	Benign	0.047
Sift	Benign	0.048	D;D;.;.
Sift4G	Benign	0.21	T;T;T;T
Polyphen		0.0010	B;.;.;.
Vest4		0.062
MutPred		0.048		Gain of relative solvent accessibility (P = 0.0166);.;.;.;
MVP		0.28
MPC		0.12
ClinPred		0.023	T
GERP RS		-0.81
Varity_R		0.034
gMVP		0.040

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: rs1414074260; hg19: chr6-15523253;