NM_183235.3:c.*1915A>T

Variant names:

• chr15-55203592-T-A
• rs1192254377
• NM_183235.3:c.*1915A>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_183235.3(RAB27A):​c.*1915A>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000134 in 149,144 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 (★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 26)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: RAB27A NM_183235.3 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.759
• Publications: 0 publications found

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: ClinGen, Labcorp Genetics (formerly Invitae), Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-1.01).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RAB27A	NM_183235.3	c.*1915A>T		3_prime_UTR_variant	Exon 7 of 7	ENST00000336787.6	NP_899058.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RAB27A	ENST00000336787.6	c.*1915A>T		3_prime_UTR_variant	Exon 7 of 7	1	NM_183235.3	ENSP00000337761.1

Frequencies

GnomAD3 genomes AF: 0.0000134 AC: 2 AN: 149144 Hom.: 0 Cov.: 26

Gnomad AFR AF: 0.0000246

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000666

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

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 246 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 202

African (AFR) AF: 0.00 AC: 0 AN: 2

American (AMR) AF: 0.00 AC: 0 AN: 2

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 2

East Asian (EAS) AF: 0.00 AC: 0 AN: 22

South Asian (SAS) AF: 0.00 AC: 0 AN: 2

European-Finnish (FIN) AC: 0 AN: 0

Middle Eastern (MID) AC: 0 AN: 0

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 210

Other (OTH) AF: 0.00 AC: 0 AN: 6

GnomAD4 genome AF: 0.0000134 AC: 2 AN: 149144 Hom.: 0 Cov.: 26 AF XY: 0.00 AC XY: 0 AN XY: 72638

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

African (AFR) AF: 0.0000246 AC: 1 AN: 40594

American (AMR) AF: 0.0000666 AC: 1 AN: 15004

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3452

East Asian (EAS) AF: 0.00 AC: 0 AN: 5112

South Asian (SAS) AF: 0.00 AC: 0 AN: 4714

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 9740

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67268

Other (OTH) AF: 0.00 AC: 0 AN: 2038

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000203), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.122 Hom.: 20

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Griscelli syndrome type 2 Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-1.0
CADD	Benign	3.6
DANN	Benign	0.095
PhyloP100		0.76
Mutation Taster		=100/0	polymorphism

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: rs1192254377; hg19: chr15-55495790;