chr18-33666280-A-G

Variant names:

• chr18-33666280-A-G
• rs55916387
• NM_030632.3:c.478-4393A>G

Variant summary

Our verdict is Benign. The variant received -12 ACMG points: 0P and 12B. BP4_Strong BS1 BS2

The NM_030632.3(ASXL3):​c.478-4393A>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0253 in 152,290 control chromosomes in the GnomAD database, including 61 homozygotes. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.025 (61 hom., cov: 32)
• Consequence: ASXL3 NM_030632.3 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.26
• Publications: 3 publications found

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]

ASXL3 Gene-Disease associations (from GenCC):

• severe feeding difficulties-failure to thrive-microcephaly due to ASXL3 deficiency syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Illumina, Orphanet, G2P
• syndromic intellectual disability

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen

ACMG classification

Our verdict: Benign. The variant received -12 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.83).
• BS1: Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.0253 (3848/152290) while in subpopulation NFE AF = 0.0365 (2482/68012). AF 95% confidence interval is 0.0353. There are 61 homozygotes in GnomAd4. There are 1753 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
• BS2: High AC in GnomAd4 at 3848 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_030632.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ASXL3	NM_030632.3	MANE Select	c.478-4393A>G		intron	N/A	NP_085135.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ASXL3	ENST00000269197.12	TSL:5 MANE Select	c.478-4393A>G		intron	N/A	ENSP00000269197.4
	ASXL3	ENST00000696964.1		c.481-4393A>G		intron	N/A	ENSP00000513003.1
	ASXL3	ENST00000681521.1		c.478-4393A>G		intron	N/A	ENSP00000506037.1

Frequencies

GnomAD3 genomes AF: 0.0253 AC: 3846 AN: 152172 Hom.: 61 Cov.: 32

Gnomad AFR AF: 0.00647

Gnomad AMI AF: 0.0570

Gnomad AMR AF: 0.0276

Gnomad ASJ AF: 0.0922

Gnomad EAS AF: 0.000192

Gnomad SAS AF: 0.00995

Gnomad FIN AF: 0.0164

Gnomad MID AF: 0.0411

Gnomad NFE AF: 0.0365

Gnomad OTH AF: 0.0316

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome AF: 0.0253 AC: 3848 AN: 152290 Hom.: 61 Cov.: 32 AF XY: 0.0235 AC XY: 1753 AN XY: 74478

African (AFR) AF: 0.00645 AC: 268 AN: 41570

American (AMR) AF: 0.0275 AC: 421 AN: 15300

Ashkenazi Jewish (ASJ) AF: 0.0922 AC: 320 AN: 3470

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5188

South Asian (SAS) AF: 0.0106 AC: 51 AN: 4822

European-Finnish (FIN) AF: 0.0164 AC: 174 AN: 10610

Middle Eastern (MID) AF: 0.0442 AC: 13 AN: 294

European-Non Finnish (NFE) AF: 0.0365 AC: 2482 AN: 68012

Other (OTH) AF: 0.0313 AC: 66 AN: 2112

Alfa AF: 0.0297 Hom.: 69

Bravo AF: 0.0252

Asia WGS AF: 0.00722 AC: 25 AN: 3478

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.83
CADD	Benign	9.3
DANN	Benign	0.78
PhyloP100		1.3
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: rs55916387; hg19: chr18-31246244;