ESPE Abstracts

Background: Fibrochondrogenesis 1 (FBCG1) is known as an autosomal recessive syndrome, which is related to short-limbed skeletal dysplasia. The disease is clinically characterized by a flat midface with a small nose and anteverted nares, significant shortening of all limb segments but relatively normal hands and feet, and a small bell-shaped thorax with a protuberant abdomen. Mutations in the gene encoding the α1 chain of type XI collagen (COL11A1) are seen to be the main cause of this disease. We present a case of a male patients with FBCG1, presenting facial dysmorphism, abnormal skeletal development, and severe short stature.

Case presentation: He had a characteristic appearance resembling Noonan syndrome such as hypertelorism, ptosis in the right eye, webbed neck, and micrognathia, and showed a triangular facial shape and displayed severe short stature (height SDS < -3). Radiographically, the ribs were broad, metaphyseal cupping at the ends, and the lumbar vertebral bodies looked platyspondyly. Whole exome sequencing revealed compound heterozygous variants, c.3478C>G (p.Pro1160Ala) and c.2771C>T (p.Pro924Leu), in the COL11A1 gene, the former of which is a novel variant.

Conclusions: We have reported a novel mutation in COL11A1, which represents the first Korean report of FBCG1 mimicking Noonan syndrome. This finding may provide insights into the phenotypic spectrum of FBCG1.