A Neonatal Manifestation of Geleophysic Dysplasia Type 1: A Case Report Highlighting Phenotypic Overlap With Al-Gazali Skeletal Dysplasia.

Geleophysic dysplasia type 1 is a rare skeletal dysplasia caused by biallelic pathogenic variants in ADAMTSL2. Affected children typically show a "happy-natured facial appearance," postnatal short stature with acromelic limb shortening, progressive joint contracture, and skin tightness. Most patients are diagnosed in childhood, and very little is known about the neonatal manifestation. We report a Japanese girl with Geleophysic dysplasia type 1, whose neonatal manifestations were enough to raise suspicion of the disorder on retrospective clinical and radiological review. At birth, she presented with joint contractures, short digits, mild pulmonary stenosis, and a normal facial appearance, and later developed severe short stature, camptodactyly, gait disturbance, and a round face with a flat nasal bridge and upslanting palpebral fissures. The clinical constellation led to a suspicion of Geleophysic dysplasia type 1 at age 3 years, and exome sequencing revealed variants in ADAMTSL2, a recurrent pathogenic missense variant (p.Ser635Leu) and a novel nonsense variant (p.Cys666*). On radiological grounds, she manifested with the same skeletal alterations in the neonatal period and at age 3 years, including severe brachydactyly with cone-shaped epiphyses and metaphyseal broadening. The distinctive skeletal phenotype overlapped with that of Al-Gazali skeletal dysplasia, an ADAMTSL2-associated potentially lethal skeletal dysplasia, suggesting a phenotypic continuum between both entities. The present case suggests that a subset of Geleophysic dysplasia type 1 may present with diagnostic physical and radiological manifestations in the neonatal period. Early recognition of neonatal skeletal features can facilitate prompt diagnosis and early clinical management for affected children.