22-18077926-G-A

Position:

• chr22-18077926-G-A

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_Strong BS1_Supporting BS2

The ENST00000329627(PEX26):​c.-203G>A variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00255 in 361,352 control chromosomes in the GnomAD database, including 14 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00067 (1 hom., cov: 32)
  • Exomes 𝑓: 0.0039 (13 hom.)
• Consequence: PEX26 ENST00000329627 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.708

Genes affected

PEX26 (HGNC:22965): (peroxisomal biogenesis factor 26) This gene belongs to the peroxin-26 gene family. It is probably required for protein import into peroxisomes. It anchors PEX1 and PEX6 to peroxisome membranes, possibly to form heteromeric AAA ATPase complexes required for the import of proteins into peroxisomes. Defects in this gene are the cause of peroxisome biogenesis disorder complementation group 8 (PBD-CG8). PBD refers to a group of peroxisomal disorders arising from a failure of protein import into the peroxisomal membrane or matrix. The PBD group is comprised of four disorders: Zellweger syndrome (ZWS), neonatal adrenoleukodystrophy (NALD), infantile Refsum disease (IRD), and classical rhizomelic chondrodysplasia punctata (RCDP). Alternatively spliced transcript variants have been identified for this gene. [provided by RefSeq, Dec 2010]

ENSG00000225335 (HGNC:):

ACMG classification

Verdict is Benign. Variant got -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.77).
• BS1: Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.00067 (102/152290) while in subpopulation SAS AF= 0.0205 (99/4822). AF 95% confidence interval is 0.0173. There are 1 homozygotes in gnomad4. There are 82 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High Homozygotes in GnomAdExome4 at 13 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
		n.18077926G>A		intergenic_region
LOC105372853	XR_001755422.2	n.*30G>A		downstream_gene_variant
LOC105372853	XR_001755423.2	n.*30G>A		downstream_gene_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PEX26	ENST00000329627	c.-203G>A		5_prime_UTR_variant	1/6	1		ENSP00000331106.5
ENSG00000225335	ENST00000607927.1	n.959C>T		non_coding_transcript_exon_variant	1/1	6

Frequencies

GnomAD3 genomes AF: 0.000664 AC: 101 AN: 152172 Hom.: 1 Cov.: 32

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: 0.0203

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.000478

GnomAD4 exome AF: 0.00392 AC: 819 AN: 209062 Hom.: 13 Cov.: 0 AF XY: 0.00558 AC XY: 647 AN XY: 116044

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000883

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000119

Gnomad4 SAS exome AF: 0.0181

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000258

Gnomad4 OTH exome AF: 0.00222

GnomAD4 genome AF: 0.000670 AC: 102 AN: 152290 Hom.: 1 Cov.: 32 AF XY: 0.00110 AC XY: 82 AN XY: 74478

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.0205

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.000473

Alfa AF: 0.0000693 Hom.: 0

Bravo AF: 0.000113

Asia WGS AF: 0.00808 AC: 28 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Peroxisome biogenesis disorder 7A (Zellweger) Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 15, 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, 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	-0.77
CADD	Benign	2.1
DANN	Benign	0.70

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: rs544836312; hg19: chr22-18560692;