Genetic Variant RAB27A:p.Ala87Thr (chr15-55228693-C-T) – ACMG Classification: Likely_pathogenic (8 pts)

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1PM2PM5PP2PP3

The NM_183235.3(RAB27A):c.259G>A(p.Ala87Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,613,508 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A87V) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

RAB27A
NM_183235.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.81

Publications

9 publications found

Variant links:

Genes affected

RAB27A (HGNC:9766): (RAB27A, member RAS oncogene family) The protein encoded by this gene belongs to the small GTPase superfamily, Rab family. The protein is membrane-bound and may be involved in protein transport and small GTPase mediated signal transduction. Mutations in this gene are associated with Griscelli syndrome type 2. Alternative splicing occurs at this locus and four transcript variants encoding the same protein have been identified. [provided by RefSeq, Jul 2008]

RAB27A Gene-Disease associations (from GenCC):

Griscelli syndrome type 2
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Orphanet

RAB27A links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_183235.3

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr15-55228692-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1348201.

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 15 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Gene score misZ: -0.51469 (below the threshold of 3.09). Trascript score misZ: 0.058062 (below the threshold of 3.09). GenCC associations: The gene is linked to Griscelli syndrome type 2.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.814

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_183235.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
RAB27A	NM_183235.3	MANE Select	c.259G>A	p.Ala87Thr	missense	Exon 5 of 7	NP_899058.1	P51159-1
RAB27A	NM_001438970.1		c.259G>A	p.Ala87Thr	missense	Exon 6 of 8	NP_001425899.1
RAB27A	NM_001438972.1		c.259G>A	p.Ala87Thr	missense	Exon 5 of 7	NP_001425901.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
RAB27A	ENST00000336787.6	TSL:1 MANE Select	c.259G>A	p.Ala87Thr	missense	Exon 5 of 7	ENSP00000337761.1	P51159-1
RAB27A	ENST00000396307.6	TSL:1	c.259G>A	p.Ala87Thr	missense	Exon 4 of 6	ENSP00000379601.2	P51159-1
RAB27A	ENST00000564609.5	TSL:1	c.259G>A	p.Ala87Thr	missense	Exon 5 of 7	ENSP00000455012.1	P51159-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152204

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000319

AC:

AN:

251174

AF XY:

0.0000147

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000145

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.00000547

AC:

AN:

1461304

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

726998

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33460

American (AMR)

AF:

0.0000895

AC:

AN:

44714

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26128

East Asian (EAS)

AF:

0.00

AC:

AN:

39684

South Asian (SAS)

AF:

0.0000348

AC:

AN:

86242

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53412

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111516

Other (OTH)

AF:

0.0000166

AC:

AN:

60380

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.419

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152204

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74348

show subpopulations

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

African (AFR)

AF:

0.00

AC:

AN:

41466

American (AMR)

AF:

0.0000655

AC:

AN:

15270

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5200

South Asian (SAS)

AF:

0.00

AC:

AN:

4838

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10602

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68036

Other (OTH)

AF:

0.00

AC:

AN:

2094

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.325

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00000907

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.0000247

AC:

ClinVar

ClinVar submissions

Significance:Uncertain significance

Revision:criteria provided, single submitter

View on ClinVar

Pathogenic

VUS

Benign

Condition

Griscelli syndrome type 2 (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.78

BayesDel_addAF

Benign

-0.0015

BayesDel_noAF

Uncertain

0.020

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.73

Eigen

Uncertain

0.52

Eigen_PC

Uncertain

0.57

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Benign

0.81

M_CAP

Uncertain

0.091

MetaRNN

Pathogenic

0.81

MetaSVM

Uncertain

-0.21

MutationAssessor

Benign

0.29

PhyloP100

7.8

PrimateAI

Pathogenic

0.87

PROVEAN

Uncertain

-3.4

REVEL

Uncertain

0.62

Sift

Uncertain

0.0070

Sift4G

Uncertain

0.050

Polyphen

0.97

Vest4

0.76

MutPred

0.80

Gain of phosphorylation at A87 (P = 0.116)

MVP

0.59

MPC

0.15

ClinPred

0.69

GERP RS

5.9

Varity_R

0.61

gMVP

0.65

Mutation Taster

=24/76

disease causing

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over