17-16217444-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_004278.4(PIGL):c.218T>C(p.Leu73Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,688 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: PIGL NM_004278.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.61

Genes affected

PIGL (HGNC:8966): (phosphatidylinositol glycan anchor biosynthesis class L) This gene encodes an enzyme that catalyzes the second step of glycosylphosphatidylinositol (GPI) biosynthesis, which is the de-N-acetylation of N-acetylglucosaminylphosphatidylinositol (GlcNAc-PI). Study of a similar rat enzyme suggests that this protein localizes to the endoplasmic reticulum. [provided by RefSeq, Jul 2008]

NCOR1 (HGNC:7672): (nuclear receptor corepressor 1) This gene encodes a protein that mediates ligand-independent transcription repression of thyroid-hormone and retinoic-acid receptors by promoting chromatin condensation and preventing access of the transcription machinery. It is part of a complex which also includes histone deacetylases and transcriptional regulators similar to the yeast protein Sin3p. This gene is located between the Charcot-Marie-Tooth and Smith-Magenis syndrome critical regions on chromosome 17. Alternate splicing results in multiple transcript variants. Pseudogenes of this gene are found on chromosomes 17 and 20.[provided by RefSeq, Jun 2010]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.918

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PIGL	NM_004278.4	c.218T>C	p.Leu73Pro	missense_variant	1/7	ENST00000225609.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PIGL	ENST00000225609.10	c.218T>C	p.Leu73Pro	missense_variant	1/7	1	NM_004278.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251144 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135712

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461688 Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4 AN XY: 727168

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: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 25, 2022

This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 73 of the PIGL protein (p.Leu73Pro). This variant is present in population databases (rs769692415, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with PIGL-related conditions. ClinVar contains an entry for this variant (Variation ID: 1430951). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.84
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
Cadd	Pathogenic	26
Dann	Benign	0.69
DEOGEN2	Uncertain	0.78	D;D;D;.
Eigen	Uncertain	0.37
Eigen_PC	Uncertain	0.24
FATHMM_MKL	Benign	0.48	N
LIST_S2	Benign	0.79	T;T;T;T
M_CAP	Uncertain	0.19	D
MetaRNN	Pathogenic	0.92	D;D;D;D
MetaSVM	Uncertain	0.44	D
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.53	T
Sift4G	Uncertain	0.0030	D;D;D;D
Polyphen		1.0	.;.;D;.
Vest4		0.81
MutPred		0.76		Loss of sheet (P = 0.0104);Loss of sheet (P = 0.0104);Loss of sheet (P = 0.0104);Loss of sheet (P = 0.0104);
MVP		0.92
MPC		0.70
ClinPred		0.96	D
GERP RS		4.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.1
Varity_R		0.96
gMVP		0.98

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: rs769692415; hg19: chr17-16120758;