Identification of a Founder GLDN Variant Associated With "Lethal" Arthrogryposis in Nunavik Inuit: Implications for Obstetrical and Long-Term Survivors' Management.

Abstract

Biallelic variants in GLDN have recently been associated with lethal congenital contracture syndrome 11 (LCCS11), a form of fetal akinesia deformation sequence (FADS) with high neonatal mortality. In this report, we describe five individuals from two Canadian Inuit families originating from different communities in Nunavik all affected with FADS and harboring a rare homozygous missense variant, [NM_181789.4:c.82G >C p.(Ala28Pro)] in GLDN. Two pregnancies presented with significant obstetrical complications including placental abruption and hemorrhage. Four infants died shortly after birth, while one survived past the neonatal period. This individual, while apparently asymptomatic during infancy, then presented with progressive neuromuscular and respiratory compromise that became more evident in adolescence. Data from a Nunavik Inuit cohort demonstrated a minor allele frequency (MAF) of 0.03571 for this variant compared to 0.00001341 in the general population, suggesting a founder effect in the Nunavik Inuit population. Our findings support the presence of a founder variant associated with LCCS11 in Nunavik Inuit populations. Our data corroborate those of other reports, demonstrating that LCCS11 is not universally lethal, but long-term survivors are at risk of progressive neuromuscular compromise. We also highlight in this report the significant obstetrical complications associated with this fetal-onset condition.