18-62072663-T-C

Variant names:

• chr18-62072663-T-C
• rs371187651
• NM_176787.5:c.2672+10A>G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Moderate BP6_Moderate

The NM_176787.5(PIGN):​c.2672+10A>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000438 in 1,598,878 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 30)
  • Exomes 𝑓: 0.0000035 (0 hom.)
• Consequence: PIGN NM_176787.5 intron
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 1.04
• Publications: 0 publications found

Genes affected

PIGN (HGNC:8967): (phosphatidylinositol glycan anchor biosynthesis class N) This gene encodes a protein that is involved in glycosylphosphatidylinositol (GPI)-anchor biosynthesis. The GPI-anchor is a glycolipid found on many blood cells and serves to anchor proteins to the cell surface. This protein is expressed in the endoplasmic reticulum and transfers phosphoethanolamine (EtNP) to the first mannose of the GPI anchor. Two alternatively spliced variants, which encode an identical isoform, have been reported. [provided by RefSeq, Jul 2008]

PIGN Gene-Disease associations (from GenCC):

• multiple congenital anomalies-hypotonia-seizures syndrome 1

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P, Orphanet, ClinGen, PanelApp Australia
• Fryns syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.35).
• BP6: Variant 18-62072663-T-C is Benign according to our data. Variant chr18-62072663-T-C is described in ClinVar as Likely_benign. ClinVar VariationId is 472225.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_176787.5. 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
	PIGN	NM_176787.5	MANE Select	c.2672+10A>G		intron	N/A	NP_789744.1
	PIGN	NM_001438896.1		c.2672+10A>G		intron	N/A	NP_001425825.1
	PIGN	NM_012327.6		c.2672+10A>G		intron	N/A	NP_036459.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PIGN	ENST00000640252.2	TSL:1 MANE Select	c.2672+10A>G		intron	N/A	ENSP00000492233.1
	PIGN	ENST00000400334.7	TSL:1	c.2672+10A>G		intron	N/A	ENSP00000383188.2
	PIGN	ENST00000638424.1	TSL:5	n.*640+10A>G		intron	N/A	ENSP00000491963.1

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 151476 Hom.: 0 Cov.: 30

Gnomad AFR AF: 0.0000486

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000830 AC: 2 AN: 241020 AF XY: 0.00000767

Gnomad AFR exome AF: 0.0000688

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000911

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000345 AC: 5 AN: 1447402 Hom.: 0 Cov.: 27 AF XY: 0.00000417 AC XY: 3 AN XY: 719834

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33166

American (AMR) AF: 0.00 AC: 0 AN: 43954

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25814

East Asian (EAS) AF: 0.00 AC: 0 AN: 39526

South Asian (SAS) AF: 0.00 AC: 0 AN: 83924

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53086

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5732

European-Non Finnish (NFE) AF: 0.00000363 AC: 4 AN: 1102334

Other (OTH) AF: 0.0000167 AC: 1 AN: 59866

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00567434), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 151476 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 73866

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000486 AC: 2 AN: 41144

American (AMR) AF: 0.00 AC: 0 AN: 15172

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5158

South Asian (SAS) AF: 0.00 AC: 0 AN: 4814

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10432

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67974

Other (OTH) AF: 0.00 AC: 0 AN: 2084

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.0000000000983081), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.0000329 Hom.: 0

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Multiple congenital anomalies-hypotonia-seizures syndrome 1 Benign:1

May 08, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.35
CADD	Benign	17
DANN	Benign	0.88
PhyloP100		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs371187651; hg19: chr18-59739896;