NM_022081.6:c.57dupT

Variant names:

• chr22-26479339-G-GA
• rs281865097
• NM_022081.6:c.57dupT

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_022081.6(HPS4):​c.57dupT​(p.Leu20SerfsTer3) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: HPS4 NM_022081.6 frameshift
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.14
• Publications: 2 publications found

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]

HPS4 Gene-Disease associations (from GenCC):

• Hermansky-Pudlak syndrome 4

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, G2P, Ambry Genetics
• Hermansky-Pudlak syndrome with pulmonary fibrosis

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 61 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_022081.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HPS4	NM_022081.6	MANE Select	c.57dupT	p.Leu20SerfsTer3	frameshift	Exon 3 of 14	NP_071364.4
	HPS4	NM_001349900.2		c.57dupT	p.Leu20SerfsTer3	frameshift	Exon 3 of 15	NP_001336829.1	F1LLU8
	HPS4	NM_001349901.1		c.57dupT	p.Leu20SerfsTer3	frameshift	Exon 3 of 15	NP_001336830.1	F1LLU8

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HPS4	ENST00000398145.7	TSL:1 MANE Select	c.57dupT	p.Leu20SerfsTer3	frameshift	Exon 3 of 14	ENSP00000381213.2	Q9NQG7-1
	HPS4	ENST00000402105.7	TSL:1	c.42dupT	p.Leu15SerfsTer3	frameshift	Exon 1 of 12	ENSP00000384185.3	Q9NQG7-3
	HPS4	ENST00000439453.5	TSL:1	n.57dupT		non_coding_transcript_exon	Exon 3 of 14	ENSP00000406764.1	F8WC53

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.1
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.13		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: rs281865097; hg19: chr22-26875305; COSMIC: COSV99314413; COSMIC: COSV99314413;