5-78128065-C-A

Variant names:

• chr5-78128065-C-A
• rs797045241
• NM_003664.5:c.1933G>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_003664.5(AP3B1):​c.1933G>T​(p.Asp645Tyr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,026 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D645N) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: AP3B1 NM_003664.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.91
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• Hermansky-Pudlak syndrome 2

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen, G2P

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.864

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003664.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AP3B1	NM_003664.5	MANE Select	c.1933G>T	p.Asp645Tyr	missense	Exon 17 of 27	NP_003655.3
	AP3B1	NM_001271769.2		c.1786G>T	p.Asp596Tyr	missense	Exon 17 of 27	NP_001258698.1
	AP3B1	NM_001410752.1		c.1933G>T	p.Asp645Tyr	missense	Exon 17 of 23	NP_001397681.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AP3B1	ENST00000255194.11	TSL:1 MANE Select	c.1933G>T	p.Asp645Tyr	missense	Exon 17 of 27	ENSP00000255194.7
	AP3B1	ENST00000519295.7	TSL:1	c.1786G>T	p.Asp596Tyr	missense	Exon 17 of 27	ENSP00000430597.1
	AP3B1	ENST00000695515.1		c.1933G>T	p.Asp645Tyr	missense	Exon 17 of 26	ENSP00000511978.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461026 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 726824

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33462

American (AMR) AF: 0.00 AC: 0 AN: 44704

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26110

East Asian (EAS) AF: 0.00 AC: 0 AN: 39660

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86224

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53386

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5760

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111356

Other (OTH) AF: 0.00 AC: 0 AN: 60364

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.68
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.28
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.82	D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.98
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Uncertain	0.18	D
MetaRNN	Pathogenic	0.86	D
MetaSVM	Uncertain	0.34	D
MutationAssessor	Pathogenic	3.4	M
PhyloP100		7.9
PrimateAI	Uncertain	0.58	T
PROVEAN	Pathogenic	-8.5	D
REVEL	Uncertain	0.58
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.85
MutPred		0.45		Gain of catalytic residue at D645 (P = 0.0191)
MVP		0.65
MPC		0.32
ClinPred		1.0	D
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.92
gMVP		0.70
Mutation Taster		=30/70	disease causing

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

Other links and lift over

dbSNP: rs797045241; hg19: chr5-77423889;