European journal of medical genetics ·10 Nov 2026 ·Added 11 Nov 2026

Larsen syndrome of La Reunion Island (B4GALT7-linkeropathy): recommendations for follow-up in the early years of life.

Odile Becquet, Brahim Boumahni, Marie-Line Jacquemont, Bérénice Doray-Roy, Mohamed El Kaissi, Fanny Ferroul, Laure Houdon, Thomas Huby, Claire Le Naour, Yael Levy, Frédérique Payet, Godelieve Morel, Mathilde Remy, Jean-Christophe Ruzic, Pierre Sabatier, Camille Schmidt, Marta Spodenkiewicz, Pauline Marzin, Silvia Iacobelli, Jean-Luc Alessandri

Biochemistry

DOI ↗

Abstract

Larsen of La Réunion Island syndrome (LRS) is an autosomal recessive disorder characterized by the association of multiple dislocation of large joints, severe dwarfism, and distinctive facial features. LRS is caused by a recurrent homozygous variant in B4GALT7 gene, which has a founder effect in La Réunion population. Proteoglycans (PG), a major component of the extracellular matrix, are composed of a core protein connected to a glycosaminoglycans side chain via a tetrasaccharide linker region. B4GALT7 encodes galactosyltransferase I, one of the enzymes involved in the biosynthesis of the linker region. Pathogenic biallelic variants in genes involved in the synthesis of this tetrasaccharide linker of PG are known as linkeropathies. Based on the retrospective study of nine patients with LRS and the literature review, we recommend management guidelines during the first years of life for patients presenting with a B4GALT7-related linkeropathy. Close multidisciplinary surveillance is recommended, focusing on osteoarticular, cervical, respiratory, cardiac, ophthalmological, growth, and psychomotor manifestations.