PIGN c.776T>C (p.Phe259Ser) variant present in trans with a pathogenic variant for PIGN-congenital disorder of glycosylation: Bella-Noah syndrome

Lyvia Neves Rebello Alves; Lívia Valle Dos Santos Silveira; Raquel Silva Dos Reis Trabach; Débora Dummer Meira; Eldamária de Vargas Wolfgramm Dos Santos; Iúri Drumond Louro

doi:10.1016/j.heliyon.2024.e27438

PIGN c.776T>C (p.Phe259Ser) variant present in trans with a pathogenic variant for PIGN-congenital disorder of glycosylation: Bella-Noah syndrome

Heliyon. 2024 Mar 5;10(6):e27438. doi: 10.1016/j.heliyon.2024.e27438. eCollection 2024 Mar 30.

Authors

Lyvia Neves Rebello Alves^{1

2}, Lívia Valle Dos Santos Silveira³, Raquel Silva Dos Reis Trabach¹, Débora Dummer Meira^{1

2}, Eldamária de Vargas Wolfgramm Dos Santos^{1

2}, Iúri Drumond Louro^{1

2}

Affiliations

¹ Núcleo de Genética Humana e Molecular, Departamento de Ciências Biológicas, Universidade Federal do Espírito Santo (UFES), Vitória, 29075-910, ES, Brazil.
² Programa de Pós-Graduação Em Biotecnologia, Universidade Federal do Espírito Santo, Vitória, 29047-105, ES, Brazil.
³ Centro de Ciências da Saúde, Curso de Medicina, Universidade Federal do Espírito Santo (UFES), Vitória, 29090-040, ES, Brazil.

Abstract

Glycosylation is the most common protein and lipid post-translational modification in humans. Congenital disorders of glycosylation (CDG) are characterized by both genetic and clinical heterogeneity, presenting multisystemic manifestations, and in most cases are autosomal recessive in inheritance. The PIGN gene is responsible for the addition of phosphoethanolamine to the first mannose in the glycosylphosphatidylinositol (GPI)-anchor biosynthesis pathway, a highly conserved process that enables proteins to bind to the cell surface membrane. Here, we report a family with two siblings pediatric cases with the exact same compound heterozygous variants in PIGN. The (c.776T > C) variant of uncertain significance (VUS) together with a known pathogenic variant (c.932T > G), resulting in clinical features compatible with PIGN-related conditions, more specific the CDG. This is the first time that PIGN variant c.776T > C is reported in literature in individuals with PIGN-congenital disorder of glycosylation (PIGN-CDG), and the current submission in ClinVar by Invitae® is specifically of our case. Detailed clinical information and molecular analyses are presented. Here, we show for the first time two affected siblings with one pathogenic variant (c.932T > G) and the c.776T > C VUS in trans. In honor of the family, we propose the name Bella-Noah Syndrome for disorder.

Keywords: Congenital disorder of glycosylation; Epileptic seizures; Glycosylation; Hypotonia; PIGN-CDG.