A novel homozygous stop-gain variant in LRRC32 causing cleft palate, proliferative retinopathy, and developmental delay

Abstract

The LRRC32 gene encodes GARP, a cell surface receptor that regulates the activation of TGF-$\beta$. This regulation of TGF-$\beta$ helps in various cellular processes, including immune regulation and tissue development. In this case report, we describe a male patient with a novel homozygous LRRC32 variant. He presented with features of global developmental delay, congenital blindness, corneal clouding, cleft palate, coarse facies, dry skin, thin extremities and hypotonia. Trio whole genome sequencing identified a likely pathogenic variant in LRRC32, denoted as c.1261C>T (p.Arg421*). No other disease-causing variants in genes linked to his clinical presentation were identified. This case expands the phenotype of previously reported cases of LRRC32 related disorder, incorporating skin manifestations and potentially linking LRRC32 to post infectious glomerulonephritis (PIGN).