22-26451546-T-C

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 0P and 14B. BP4_Strong BP6_Moderate BS1 BS2

The NM_022081.6(HPS4):c.*1687A>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00125 in 152,272 control chromosomes in the GnomAD database, including 5 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★).

• Frequency:
  • Genomes: 𝑓 0.0013 (5 hom., cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: HPS4 NM_022081.6 3_prime_UTR
• Clinical Significance: Benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.458

Genes affected

HPS4 (HGNC:15844): (HPS4 biogenesis of lysosomal organelles complex 3 subunit 2) This gene encodes a protein component of biogenesis of lysosome-related organelles complexes (BLOC). BLOC complexes are important for the formation of endosomal-lysosomal organelles such as melanosomes and platelet dense granules. Mutations in this gene result in subtype 4 of Hermansky-Pudlak syndrome, a form of albinism. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2012]

ACMG classification

Verdict is Benign. Variant got -14 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.92).
• BP6: Variant 22-26451546-T-C is Benign according to our data. Variant chr22-26451546-T-C is described in ClinVar as [Benign]. Clinvar id is 340964.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS1: Variant frequency is greater than expected in population eas. gnomad4 allele frequency = 0.00125 (191/152272) while in subpopulation EAS AF= 0.0334 (173/5178). AF 95% confidence interval is 0.0293. There are 5 homozygotes in gnomad4. There are 118 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.
• BS2: High Homozygotes in GnomAd at 5 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HPS4	NM_022081.6	c.*1687A>G		3_prime_UTR_variant	14/14	ENST00000398145.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HPS4	ENST00000398145.7	c.*1687A>G		3_prime_UTR_variant	14/14	1	NM_022081.6	P2

Frequencies

GnomAD3 genomes AF: 0.00126 AC: 192 AN: 152154 Hom.: 5 Cov.: 33

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.0333

Gnomad SAS AF: 0.00248

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00144

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 14 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 12

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00125 AC: 191 AN: 152272 Hom.: 5 Cov.: 33 AF XY: 0.00159 AC XY: 118 AN XY: 74448

Gnomad4 AFR AF: 0.0000481

Gnomad4 AMR AF: 0.000131

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.0334

Gnomad4 SAS AF: 0.00228

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00142

Alfa AF: 0.000264 Hom.: 0

Bravo AF: 0.00178

Asia WGS AF: 0.00895 AC: 31 AN: 3478

ClinVar

Significance: Benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hermansky-Pudlak syndrome 4 Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

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 and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.92
Cadd	Benign	1.0
Dann	Benign	0.53

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: rs3752588; hg19: chr22-26847512;