18-33578640-CAA-C

Variant names:

• chr18-33578640-CAA-C
• rs1599364162
• NM_030632.3:c.10_11delAA

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_030632.3(ASXL3):​c.10_11delAA​(p.Lys4GlufsTer57) variant causes a frameshift change. The variant allele was found at a frequency of 0.000000825 in 1,212,692 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 8.2e-7 (0 hom.)
• Consequence: ASXL3 NM_030632.3 frameshift
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 3.83

Genes affected

ASXL3 (HGNC:29357): (ASXL transcriptional regulator 3) This gene encodes a protein containing a plant homeodomain (PHD) zinc finger domain that plays a role in the regulation of gene transcription. The encoded protein has been shown to negatively regulate lipogenesis by binding to and inhibiting the transcriptional activity of two nuclear hormone receptors, oxysterols receptor LXR-alpha (LXRalpha) and thyroid hormone receptor beta (TRbeta). The encoded protein may also inhibit histone deubiquitination. Mutations in this gene have been identified in human patients with Bainbridge-Ropers syndrome, which is characterized by feeding difficulties, developmental delay and other features. [provided by RefSeq, May 2017]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 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 14 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 18-33578640-CAA-C is Pathogenic according to our data. Variant chr18-33578640-CAA-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 817736.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ASXL3	NM_030632.3	c.10_11delAA	p.Lys4GlufsTer57	frameshift_variant	Exon 1 of 12	ENST00000269197.12	NP_085135.1
ASXL3	XM_005258356.2	c.10_11delAA	p.Lys4GlufsTer58	frameshift_variant	Exon 1 of 13		XP_005258413.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ASXL3	ENST00000269197.12	c.10_11delAA	p.Lys4GlufsTer57	frameshift_variant	Exon 1 of 12	5	NM_030632.3	ENSP00000269197.4

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome AF: 8.25e-7 AC: 1 AN: 1212692 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 600676

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000104

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 30

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Jul 19, 2018

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.10_11delAA variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The c.10_11delAA variant is not observed in large population cohorts (Lek et al., 2016). The c.10_11delAA variant causes a frameshift starting with codon Lysine 4, changes this amino acid to a Glutamic acid residue, and creates a premature Stop codon at position 57 of the new reading frame, denoted p.Lys4GlufsX57. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. Therefore, this variant is likely pathogenic; however, the possibility that it is benign cannot be excluded. -

Computational scores

Source: dbNSFP v4.3

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: rs1599364162; hg19: chr18-31158604;