Genetic Variant AP3B1:p.Gln891His (chr5-78039179-C-G) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

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

The NM_003664.5(AP3B1):c.2673G>C(p.Gln891His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,832 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

AP3B1
NM_003664.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.124

Variant links:

Genes affected

AP3B1 (HGNC:566): (adaptor related protein complex 3 subunit beta 1) This gene encodes a protein that may play a role in organelle biogenesis associated with melanosomes, platelet dense granules, and lysosomes. The encoded protein is part of the heterotetrameric AP-3 protein complex which interacts with the scaffolding protein clathrin. Mutations in this gene are associated with Hermansky-Pudlak syndrome type 2. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2012]

AP3B1 links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AP3B1	NM_003664.5 link	c.2673G>C	p.Gln891His	missense_variant	Exon 23 of 27	ENST00000255194.11	NP_003655.3	O00203-1A0A0S2Z5J4
AP3B1	NM_001271769.2 link	c.2526G>C	p.Gln842His	missense_variant	Exon 23 of 27		NP_001258698.1	O00203-3A0A0S2Z5J4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AP3B1	ENST00000255194.11 link	c.2673G>C	p.Gln891His	missense_variant	Exon 23 of 27	1	NM_003664.5	ENSP00000255194.7		O00203-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251458

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135904

show subpopulations

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:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461832

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727214

show subpopulations

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:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Hermansky-Pudlak syndrome 2

Uncertain:1

Nov 19, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamine, which is neutral and polar, with histidine, which is basic and polar, at codon 891 of the AP3B1 protein (p.Gln891His). This variant is present in population databases (rs770455413, gnomAD 0.003%). This variant has not been reported in the literature in individuals affected with AP3B1-related conditions. ClinVar contains an entry for this variant (Variation ID: 568074). 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 tolerated. 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

0.22

BayesDel_addAF

Benign

-0.14

BayesDel_noAF

Benign

-0.34

CADD

Benign

DANN

Uncertain

0.98

DEOGEN2

Uncertain

0.48

T;.

Eigen

Benign

-0.53

Eigen_PC

Benign

-0.46

FATHMM_MKL

Uncertain

0.88

LIST_S2

Benign

0.74

T;T

M_CAP

Benign

0.035

MetaRNN

Uncertain

0.62

D;D

MetaSVM

Benign

-1.0

MutationAssessor

Pathogenic

3.0

M;.

PrimateAI

Uncertain

0.57

PROVEAN

Uncertain

-2.6

D;D

REVEL

Benign

0.20

Sift

Uncertain

0.014

D;D

Sift4G

Benign

0.12

T;T

Polyphen

0.0010

B;.

Vest4

0.81

MutPred

0.49

Loss of sheet (P = 0.1158);.;

MVP

0.57

MPC

0.068

ClinPred

0.73

GERP RS

-0.31

Varity_R

0.20

gMVP

0.77

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