Is PIGN p.Leu424= (c.1270C>T) pathogenic?

PIGN p.Leu424= (c.1270C>T) is classified Likely benign in PIGN (ClinVar, Single submitter, 1 submitter; last evaluated 2022-12-24). Absent from gnomAD v4.1; Associated with multiple congenital anomalies-hypotonia-seizures syndrome 1.

What condition is associated with PIGN p.Leu424= (c.1270C>T)?

PIGN p.Leu424= (c.1270C>T) is associated with multiple congenital anomalies-hypotonia-seizures syndrome 1 (ClinVar).

How common is PIGN p.Leu424= (c.1270C>T) in the general population?

PIGN p.Leu424= (c.1270C>T) is absent from gnomAD v4.1 (gnomAD).

PIGN p.Leu424=

c.1270C>T · rs2513120551 · VCV2823877

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

multiple congenital anomalies-hypotonia-seizures syndrome 1

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	<0.2	all four deltas below 0.2 · G>C here scores Δ0.29 · evaluated, not missing
Constraint at this position
Conservation	phyloP 3.3	GERP 1.2, phastCons 1
Overall
CADD	6.44	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: PIGN
Protein: p.Leu424=
Coding: c.1270C>T
MANE Select: NM_176787
dbSNP: rs2513120551
Type: single nucleotide variant
Location: chr18:62113298 (GRCh38)
Gene constraint: LOEUF 1.46 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 88.33

Full PIGN gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

multiple congenital anomalies-hypotonia-seizures syndrome 1 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

PIGN c.1251+1G>A Pathogenic/Likely pathogenic ★★ same condition
PIGN c.1252-2A>G Pathogenic/Likely pathogenic ★★ same condition
PIGN c.1434+5G>A Pathogenic/Likely pathogenic ★★ same condition
PIGN c.1574+1G>A Likely pathogenic ★★ same condition
PIGN c.1674+1G>A Likely pathogenic ★★ same condition
PIGN c.1674+1G>C Pathogenic ★★ same condition
PIGN c.1675-1G>T Pathogenic/Likely pathogenic ★★ same condition
PIGN c.222-1G>A Likely pathogenic ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/pign-p-leu424 (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown