A new case of Greenberg dysplasia and literature review suggest that Greenberg dysplasia, dappled diaphyseal dysplasia, and Astley–Kendall dysplasia are allelic disorders

Abstract

Background: Greenberg dysplasia is a rare, autosomal recessive, prenatal lethal bone dysplasia caused by biallelic pathogenic variants in the lamin B receptor (LBR) gene. Pathogenic variants in LBR are also associated with Pelger–Huët anomaly, an autosomal dominant benign abnormality of the nuclear shape and chromatin organization of blood granulocytes, and Pelger–Huët anomaly with variable skeletal anomalies, a mild, regressing to moderate–severe autosomal recessive condition. Conditions with abnormal sterol metabolism and different genetic basis have clinical and radiographic features similar to Greenberg dysplasia, for example X-linked dominant chondrodysplasia punctata, Conradi–Hünermann type, and CHILD syndrome, and other conditions with unknown genetic etiology display very similar features, for example, dappled diaphyseal dysplasia and Astley–Kendall dysplasia. Methods: We present a fetus with typical clinical and radiographic features of Greenberg dysplasia, and review the literature. Results: Genetic testing confirmed the diagnosis Greenberg dysplasia: homozygosity for a pathogenic variant in LBR. Conclusion: Comparing the clinical and radiographic phenotypes of Greenberg dysplasia, dappled diaphyseal dysplasia, and Astley–Kendall dysplasia, we suggest that these are allelic disorders.